Book of abstracts - SFFE

Book of abstracts
Renewable Energy Research
Conference 2010
Trondheim, Norway
7 – 8 June 2010
The Centre for Renewable Energy

Table of contents
Wind Energy.................................................... 1
Posters.................................................... 22
Solar Cells........................................................ 25
Posters.................................................... 45
Hydropower.................................................... 59
Posters.................................................... 79
Bioenergy........................................................ 88
Poster..................................................... 109
Renewable Energy in Transportation.............. 111
Posters.................................................... 137
Zero Emission Buildings................................... 150
Posters.................................................... 167
Ocean energy................................................... 173
Social Studies of Renewable Energy................. 189

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ABSTRACTS
Wind Power
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Forecasting scenarios of wind power generation for the
next 48 hours to assist decision-making in the electricity
industry
Nicholas Cutler a (n.cutler@unsw.edu.au),
Hugh Outhred a (h.outhred@unsw.edu.au)
Iain MacGill a (i.macgill@unsw.edu.au)
a University of New South Wales, Sydney, Australia
Wind power forecasts can assist decision-making in day-to-day power system operation,
and thus facilitate wind power integration. This paper will present the work in progress
for the current wind power forecasting project undertaken in collaboration with the
Australian Energy Market Operator (AEMO). The aim of the project is to develop a
visual decision support tool to forecast large rapid changes in wind power to assist the
management of power system security in the Australian National Electricity Market. The
approach is to utilise Numerical Weather Prediction (NWP) data at multiple grid points in
the vicinity of each wind farm of interest to produce automated multiple potential
scenarios for wind farm generation. Data from the ECMWF global forecast model has
been collected along with the observations from 18 wind farms in south-eastern
Australia. The methodologies and some resulting forecasts will be discussed and
compared with more conventional wind power forecasting methods and presentation
formats. The most important viewpoint is on how the information could be interpreted by
the forecast user and be used to assist decision-making.
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Wind Energy Probability Validation At Ahmednagar
Wind Farm
Mr. M. M. Hapse a (hapsemanik@rediffmail.com)
Dr. A.G. Thosar b (aprevankar@rediffmail.com)
Electrical Engineering Department
Government College Of Engineering Aurangabad
Maharashtra (India)
Abstract— The wind speed is measured with the help of three anemometers S30, 45, S60
placed at 30 m, 45 m, and 60 m height. Mean values were recorded and stored for every
hour using a Data logger. For accounting Wind Turbine Generator (WTG) tower height,
data recorded from S60 anemometer at 60 m height is used for analysis purpose. This
paper analyzes the probability distribution of wind speed data recorded of Maharashtra
Energy Development Agency (MEDA) wind farm at Ahmednagar (India). The main
objective is to validate the wind energy probability by using probability distribution
function (PDF) of available wind potential.
The energy generated from wind for any time interval is equal to area under
power curve multiply by time in hours for that time interval. To estimate the wind energy
probability hourly wind speed data for one year interval is selected. Weibull distribution
is adopted in this study to fit the wind speed data. The scale and shape parameters were
estimated by using maximum likelihood method. The goodness of fit tests based on the
Probability density function (PDF) conducted to show that the distribution adequately fits
the data. It is found from the curve fitting test that, although the two distributions are
suitable for describing the probability distribution of wind speed data, the two parameter
weibull distribution is more appropriate than the lognormal distribution.
Curve fitting for weibull and lognormal
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Small scale wind power harnessing in Colombian oil industry
facilities: Wind resource and technology issues
Mauricio Giraldo a (mauricio.giraldo@correo.upb.edu.co),
Cesar Nieto a (cesar.nieto@correo.upb.edu.co),
Ana C. Escudero a (ana.escudero@correo.upb.edu.co),
Juan C. Cobos b (juan.cobos@ecopetrol.com.co),
Fernando Delgado b (fernando.delgado@ecopetrol.com.co)
a Universidad Pontificia Bolivariana, Medellín, Colombia
b Ecopetrol, Colombia
Looking to improve its national and international standing, Colombia’s national oil
company, Ecopetrol, has set its goal on becoming involved on the production of energy
from multiple sources, most importantly, on having an important percentage of its
installed capacity from renewable sources. Part of this effort entices the evaluation of
wind power potential on its facilities, including production, transportation and
administrative, as well as identifying those technologies most suitable for the specific
conditions of an equatorial country such as Colombia.
Due to the lack of adequate site information, the first step consisted in superimposing
national data to the facilities map of the company; this allowed for the selection of the
first set of potential sites. From this set, the terminal at Coveñas-Sucre was selected
taking into account not only wind resource, but ease of access and power needs, as well
as having a more or less representative wind potential in comparison to the rest of the
country. A weather station was then installed to monitor wind variables.
Measurements taken showed high variations in wind direction, and relatively low
velocity profiles, making most commercially available wind turbines difficult to
implement. In light of the above, a series of iterative steps were taken, first considering a
range of individual Vertical Axis Wind Turbines (VAWT), given their capacity to adapt
to changing wind directions. However, wind speed variations proved to be a challenge for
individual VAWT’s, i.e. Darriues turbines do not work well with low wind speeds, and
Savonius turbines are not efficient of high wind speeds. As a result, a combined Darrieus-
Savonius VAWT was selected given the capacity to adapt to both wind regimes, while at
the same time modifying the size and shape of the blades in order to adapt to the lower
average wind speeds present at the site.
The resulting prototype is currently under construction and is scheduled to be installed
for testing on the beginning of the second semester 2010. After testing and validation, it
is expected to install the developed turbine in several other sites around the country.
Acknowledgments
This work was conducted under the support of project code 1210-471-21830, funded by
Colciencias and Ecopetrol.
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Wind Resource Analysis At Northern Region of Bangladesh
Faruk Ahmed Sohag and M. M. Alam
Dept. Of Mechanical Engineering, Bangladesh University of Engineering and
Technology, Dhaka-1000,
Email : fahmed.buet@gmail.com
Abstract:
The interest in renewable energy has been revived over last few years especially
after global awareness regarding the ill effects of fossil fuel burning. The wind has
always been a natural ally in propelling our societies forward. Bangladesh has
fairly wind energy potential, exploitation of the wind energy is still in the crawling
level. A study and statistical analysis has been carried out to identify sites with a
high wind potential to apply wind programme suitable at the sites.Here the
investigation is carried out mainly at Naogaon, Pakshy, Chapai Nawabganj at the
Northern region of Bangladesh based on data provided by Local Government
Engineering Department (LGED) in year 2003 on hourly based data and from
Bangladesh Meteorological Department(BMD) on 3 hourly based data at Rajshahi
And Ishourdi.The data provided were measured at 30 meter height from LGED and
10 meter height from BMD. The analysis was done between the months of April to
September, as study showed higher wind potential between these months. Monthly
based Weibull Shape factor and Scale factor were determined and reflected in
velocity, energy and frequency Histograms, Velocity duration curves, comparison
between observed and calculated Weibull Cumulative function and Probability
function graphs. For comparison the data provided by LGED and Bangladesh
Meteorological Department (BMD) were compared & significant variation was
noticed, as there was height and site variance between them. The data studied
showed the higher wind potential at mid day and late night and between months
June to September flowing close to 4 to 6 m/s range. At Pakshy peak average speed
occurs from 12 to 18 hours in every month. At Nawabganj peak average wind
speed occurs from 13 to 20 hours & at Naogaon from 15 to 20 hours for every
month. It is found that the value of shape factor (k) remains in between 1.1 to 3.5
and that of scale factor (c) remains between 2.5 to 5.5. At Chapai Nawabganj the
average wind power per unit area of approach was about 23.01w/m 2 which is
higher than other location. Average wind power at Pakshy and Naogaon is 15.33 &
8.02 w/m 2 respectively. The speed range was not satisfactory for wind power
generation well below it demands and also because high speed range of wind
potential showed very little duration so mainly wind pumping system is suggested
at the investigated sites at northern region of Bangladesh.
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Wake effects on wind turbine performance
Muyiwa S. Adaramola (muyiwa.adaramola@ntnu.no),
Per-Åge Krogstad (per.a.krogstad@ntnu.no)
Department of Energy and Process Engineering
Norwegian University of Science and Technology, Trondheim, Norway
Introduction
In existing wind farms, where it is impossible to change the distance between turbines, it
is likely that the overall wind farm efficiency can be improved by strategically control of
the power extraction of the individual turbines. One of the ways to achieved this is by
changing the yaw angle of the upstream turbines. This change can significantly affect the
performance of the upstream turbines and hence, their wake properties and therefore, the
performance of the turbines further downstream. This study presents a wind tunnel study
of the performance characteristics of a model wind turbine operating in the wake of
another turbine operating at yawed condition. This information might be useful for
validation of computational studies, and also provide a better understanding of the overall
flow structure, helping proper planning and designing of wind farms.
Experimental Approaches
The experiments were performed in a low-speed, closed-return wind tunnel with a testsection
of 1.9 m (height) x 2.7 m (width) x 11.0 m (length). For this study, two model
turbines with 3-bladed upwind rotors and the same rotor diameter of 0.90 m were used.
The torque generated by the wind turbine was measured directly by a torque sensor
mounted on the rotor shaft. The downstream turbine is located at three rotor diameters
from the upstream turbine and the upstream yaw angle was varied from 0 to 30 degree.
Overview of Results
It was observed that as the upstream turbine yaw angle increases there is a gradual
increase in the power coefficient of the downstream turbine at a given tip speed ratio
except within the stalled region. This is because operating the upstream turbine in yaw,
less power may be extracted from the air flow by the upstream turbine. The downstream
turbine is therefore exposed to higher wind speed compared to when the turbines are in
an in-line arrangement. This results in the improved performance of the downstream
turbine. For a constant rotor speed, it was observed that with increasing yaw angle of the
upstream turbine, the cut-in wind speed at which the downstream turbine can start
producing power is slightly reduced. The normalized maximum power coefficient shows
that the gain in relative maximum power coefficient of the downstream turbine increases
with increasing yaw angle of the upstream turbine. At a yaw angle of 10 o the gain is only
about 4% compared to when the upstream turbine is operating in non-yawed position, and
this increases to about 29% at yaw angle of 40 o (the largest yaw angle considered in this
study). In addition, it was found that by operating the upstream turbine at appropriate
yaw angle and using a relatively small distance of separation between the turbines, the
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efficiency of the wind farm (two model wind turbines) is comparable to when the
distance between them is high and the upstream turbine is not yawed. Therefore,
operating the upstream turbine at a suitable yaw angle will not only improve the total
wind farm power output but will also reduce the space required for a given wind farm.
Renewable Energy Research Conference 2010 7

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The Design of a Rotor for a Floating Offshore Wind Turbine
Karl O. Merz a (karl.merz@ntnu.no)
a Norwegian University of Science and Technology (NTNU)
Previous design and optimization studies on horizontal axis wind turbine rotors have
shown that the optimal blade design differs from that which provides maximum power
coefficient. Loads on the blade can be reduced significantly if the power coefficient is
reduced slightly. This tradeoff can lead to a moderate reduction in cost of energy.
It would seem that this tradeoff -- reducing the efficiency of the rotor in order to reduce
the loads -- would be more beneficial for a floating wind turbine than for one mounted
atop a fixed support structure. The reason is that the load path to ground is much longer
on a floating wind turbine, so it costs more to carry a "unit" of rotor load. It follows that
we should expect the optimal rotor of a floating wind turbine to have a somewhat
different geometry than the optimal rotor of a land-based wind turbine. It is the objective
of this study to determine the rotor design that gives the lowest cost-of-energy for a
floating wind turbine.
This phase of the investigation is limited to stall-regulated rotors. Stall-regulated rotors
are of interest for a floating wind turbine because they replace the active mechanical
systems of a pitch-regulated turbine, which require maintenance, with passive structures,
which do not.
Standard aerodynamic analysis methods are used, based upon the blade element
momentum method. The structural model is based upon modal dynamics. The dynamic
analysis is conducted in the frequency domain. This requires a linear model. Methods
were developed to linearize the aerodynamic behavior under stalled conditions.
A gradient-based optimization algorithm (BFGS) is used. The optimization consists of
an "outer" loop, which optimizes the geometry of the rotor, and an "inner" loop, which
optimizes the material thickness distribution along the blade for each geometry. The cost
function is estimated based upon elementary structural analysis of various components.
Collection of results is in progress.
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Flexible wind turbine rotors modelled with the
Corotational Finite Element Method
Karl Jacob Maus a (karl.maus@umb.no),
Tor Anders Nygaard ab (tor.anders.nygaard@ife.no)
a Norwegian University of Life Sciences, dept. of Mathematical Sciences and
Technology
b Institue for Energy Technology, Norway
The wind industry is building larger wind turbines, with current rotor diameters in
excess of 120m. As the blades grow longer, and the mass of the blades is further
optimized, the detailed modelling of rotor flexibility becomes more important.
One way of dealing with geometric nonlinearities is the corotational approach. We
here use a rotating wind turbine blade modelled with beam elements as an example.
The element equations for an element are stated in a coordinate system attached to
the midpoint of that element, in the current configuration. This allows use of
standard small-strain elements, also with large global deflections, given that the
element resolution is sufficient. The element equations are transformed to and
assembled in one common substructure coordinate system. In this example we use
a Cartesian coordinate system co-rotating with the rotor (here called the rotor
system). The general beams used for the investigation have 6 degrees of freedom in
each node; three rotations and three displacements. Use of the full (user-defined,
generated from standard element libraries or generated from a full 3D FEM
representation) stiffness- and mass matrices allows modelling of cross-coupling
effects caused by e.g. offset between shear- and mass centres. Recent developments
of interpolation functions tailored to rotating beams can potentially improve the
accuracy and convergence.
Time-domain solutions are obtained by the generalized-
Comparisons of the numerical results are made with selected benchmark cases.
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Performance evaluation of a hydraulic offshore wind turbine
(The Delft Offshore Turbine)
A. Jarquin Laguna (A.JarquinLaguna@student.tudelft.nl),
N.F.B. Diepeveen (N.F.B.Diepeveen@tudelft.nl),
P.S. Albers (P.S.Albers@tudelft.nl)
DUWIND, Delft University of Technology, the Netherlands
The Delft Offshore Turbines (DOTs) is a DUWIND research project that focuses on
reducing the cost of offshore wind energy by bringing a radical change in offshore wind
turbine technology. The main concept is to centralize electricity generation using
pressurized seawater from individual wind turbine pumping systems. The idea behind the
DOTs is that the high power to weight ratio from hydraulic drive systems gives the
opportunity for a reduced nacelle mass and increased reliability of components by
eliminating the use of individual geartrains and generators. This paper presents a first
evaluation of the overall performance of a single DOT using a baseline rotor (NREL 5
MW offshore wind turbine) with a possible high tip-speed operation up to 120 m/s. A
physical modelling approach was used, where the main system subcomponents from
different physical domains (mechanical, hydraulic and aerodynamics) were modelled and
integrated in a single environment with MATLAB-Simulink. The steady-state response
of the system was obtained as a function of wind speed. The main advantage of a DOT
with a high speed operation is the possibility to get more mechanical power from wind
speeds in the range of 12 to 17 m/s, with power outputs up to 8 MW. An overall system
performance of 80% was obtained (including pump/motor efficiencies, friction losses),
with a final power output of 6.4 MW (28% more than a typical 5 MW turbine). Taking
into account the wind speed probability with a typical offshore weibull distribution for
the North Sea, a gross annual energy production of 24,991 MWh was obtained (2% less
with respect to a typical 5 MW turbine), therefore it can be foreseen that the success of an
offshore hydraulic turbine will not be dictated by the energy performance but by other
potential advantages resulting in reduced cost of the overall system.
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Comparison of conventional and hydraulic drive train mass and their
influence on support structure design.
N.F.B. Diepeveen, W.E. De Vries
DUWIND, TU Delft
The Netherlands
Email: n.f.b.diepeveen@tudelft.nl, w.e.devries@tudelft.nl
As the offshore wind industry is striving to reduce the cost of energy, the size of wind
turbines is ever increasing. Currently, the maximum installed capacity per turbine
offshore is 5 MW and the maximum rotor diameter is 126 meters.
With an increase in power capacity the rotor and the drive train components such as the
gearbox, generator and power electronics also increase in size which is most notable in
terms of the increase of mass. Greater power thus leads to greater loads and larger mass
of components. In general the relation between rated power capacity and mass of
components follows a second degree polynomial.
Support structures for offshore wind turbines are designed within the soft-stiff region.
When the rotor-nacelle assembly becomes heavier, more material is required to fulfill
strength and stiffness requirements. A consequence is that the monopile is not a feasible
option for large turbines in water depths over 25 m.
From an installation and fabrication point of view, the monopile is an attractive support
structure concept compared to other concepts for intermediate water depths. Therefore it
may be desirable to expand the range of water depths for which the monopile is
applicable.
The application of a hydraulic drive train increases the power density of the rotor-nacelle
assembly and reduces the mass of the support structure.
The objective of the research presented in this paper is to demonstrate the possible
reduction of the mass of the nacelle and hence the support structure mass by making use
of fluid power drives instead of conventional systems.
In this paper two different hydraulic drive train configurations are defined. As a
reference, one conventional drive train configuration is also specified. On the basis of
trend analysis these configurations are assigned a specific mass as a function of the rotor
diameter.
For the three turbine definitions with the associated nacelle masses, monopile support
structures are designed for two reference sites and three different rotor sizes. By
comparing the results it is determined to what extent the reduction of mass in the nacelle
leads to reduction in the amount of support structure steel.
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Definition of a 10 MW reference wind turbine - rotor blades
Lars Frøyd (lars.froyd@ntnu.no),
NTNU. Dept. of Energy and Process Technology
The size of commercial wind turbines have increased from approximately 1 MW in 1990
to 5-6 MW in today's largest offshore wind turbines. When moving offshore and to
floating turbines, the increased cost of substructures and installation and maintenance
favours larger units. The economic optimal size is not known, but the floating (and
bottom fixed) offshore wind farms of tomorrow may consist of turbines with a capacity
of 10 MW or more.
The present 5-6 MW turbines are in the borderland of what is possible with today’s
technology. Moving to larger turbines requires different approaches than merely scaling
the turbine components. Large technological challenges relates to blade design to achieve
lightweight blades that are sufficiently strong and with improved dynamic characteristics
to reduce fatigue loads. Another important aspect is nacelle weight, which can be reduced
by novel direct-drive topologies and lightweight generator technology.
To facilitate research on large offshore wind turbines, a reference wind turbine will be
defined with a capacity of 10 MW. All turbine specifications and details will be
published and be freely available for other researchers and institutions. The idea is not to
create an optimal design, but to create a common reference case for further research,
based on the current state-of-the-art. The reference turbine will include one floating
configuration and one bottom mounted configuration on a jacket foundation, both sharing
the same rotor/nacelle assembly.
What is presented here, are the preliminary results of the ongoing work, which includes
definition of the rotor blades’ geometric, aerodynamic and structural properties. The
rotor blades are designed using an in-house design tool based on blade element
momentum theory, including quasi-3D effects due to rotational augmentation and tip-loss
effect. The structural properties of the blades are then determined, based on the shape of
the blade shell and definition of the blade main spar and shear webs.
Keywords: Offshore wind turbines, integrated design tools, wind turbine blades
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Development of small scale standalone Wind-Desalination
model.
(rajarajan.rathinavelu@haw-hamburg.de ),
Hamburg University of Applied Sciences, Hamburg, Germany
There is no doubt that the global freshwater level is going down with ever escalating
demand. The abundant amount of water available in the seas can be made drinkable by
desalination process. One of the major limitations of desalination process is its high
energy requirement. On the other hand the global warming is threatening the mankind
and is also the major reason for water scarcity. Unstable oil prices and the damage caused
by use of fossil fuels to the environment are collectively driving the world to resort to
renewable energy resources. But renewable energy technologies are expensive and
supply intermittent power. Since wind energy is more economic among all the other
renewable energy sources and is suitable for remote areas, it could be coupled with high
energy demanding desalination technologies. Wind-driven desalination process is one of
the most feasible uses of renewable energies for desalting seawater.
The project deals with developing concept of coupling renewable energy technologies,
particularly wind energy and desalination. In brief the project aims at developing an
economic standalone wind-RO model. Moreover the economics of the Wind-RO concept
is also analyzed comparing the real time models of such kinds. In this process the
experimental results of potable water produced at laboratory is being used for scaling up
the wind-RO unit. For this A 2.5 kW wind turbine is chosen for this study. The approach
employed to meet the objectives are to calculate cost of energy and cost of water of the
wind-RO unit. Finally the report concludes representation of with the standalone wind-
RO unit’s with its applicability, advantages and ways to improve it.
Figure 1 – This is an example figure
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This approach which combines desalination and wind energy is certainly a positive step
forward in meeting the demands of potable water without depleting fossil fuel reserves
and hence deserves careful consideration in the future efforts of desalination process.
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EFFECT OF FOUNDATION MODELING METHODOLOGY ON THE
DYNAMIC RESPONSE OF OFFSHORE WIND TURBINE SUPPORT
STRUCTURES
Eric Van Buren
Marine Technology, Department of Civil and Transport Engineering
Norwegian University of Science and Technology
Høgskoleringen 7a, 7491 Trondheim, Norway
Tel: (+47) 735 94 047, Fax: (+47) 735 94 506, eric.vanburen@ntnu.no
ABSTRACT
If offshore wind energy is to play a major role in the future of renewable energy
production, costs for the design and construction of the support structures and
foundations must be significantly reduced. As thousands of these structures are likely to
be designed and built, it is imperative that foundation design and modeling techniques are
carefully scrutinized, and if needed, updated and improved. In this young age of offshore
wind energy production, there is quite a bit of uncertainty as to what support structure
topology is the most sensible solution. Currently there is an extremely limited number of
full scale offshore wind turbines in operation, thus the only practical method for
comparing the various tower concepts is through numerical modeling. One potentially
important aspect of these models is the method chosen to represent the contribution of the
foundation of the structure. When preliminarily comparing several different tower
topologies, it is quite convenient to simply assume fixed boundary conditions at the
foundation interface. This allows for the towers to be compared regardless of the soil
conditions they will encounter, and makes the computer models much simpler to create
and much faster in computation. Alternatively, the foundations of offshore wind turbine
support structures can be represented using some simple design and analysis techniques
found in the offshore steel structure design codes. These methods utilize several rather
simplistic displacement-force techniques for determining the response of offshore
foundations. This displacement-force relationship can be modeled using a number of nonlinear
springs and implemented into a numerical model of an offshore wind turbine
support structure. The important question then is this: What is the discrepancy in the
results of a dynamic analysis of an offshore wind turbine support structure when using
fixed boundary conditions as compared to implementing a foundation model based on the
methods found in the design codes? In this work two offshore wind support structures are
modeled in the wind turbine analysis program HAWC2; a four-legged, full height lattice
tower with piled foundations, and a traditional monotower with a monopile foundation. A
dynamic analysis including turbulent wind conditions has been carried out for both
towers with various foundation models including fixed conditions and some different
representations of the foundation reaction in both clay and sand. The results are compared
based on the calculated natural frequencies of the structure, the moments and forces
experienced in the base of the towers, and the displacements experienced at the nacelle of
each structure.
KEYWORDS: offshore wind turbine, foundation modeling, piled foundation
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A comparison of existing and conceptual designs for floating wind
turbines
Anders Myhr a , Fredrik Even Hansen a , Ulrik Møller a and Tor Anders Nygaard ab
a
Department of Mathematical Sciences and Technology
Norwegian University of Life Sciences (UMB), 1432 Ås, Norway
b Institue for Energy Technology, Norway
email: anders.myhr@umb.no
Objectives:
1. Comparisons of the Taut-Line-Buoy (TLB) and Spar-Buoy (SB) concepts, by
wave tank experiments.
2. Support of computational tool development efforts, by provision of experimental
data.
Methodology:
Three experimental wind turbine floaters/towers, the SB UMB-Hywind, TLB Njord A
and TLB Njord B, have been built in scale 1:100. These platforms in full scale are
intended to support a 5MW turbine based on the IEA-OC3 project [1]. The scale models
have sensors for hub accelerations, floater motions, tension in the mooring lines and
tower bending moments. The experimental data will be compared with numerical
simulations with both ANSYS and by the 3Dfloat code that has aero-servo-hydro-elastic
capabilities.
Outline of results:
The UMB-Hywind has the same overall properties as the OC3-Hywind. The rigid-body
definition of the floater has been supplemented with a reverse-engineered steel floater
with rock and water ballast. This allows comparisons of steel masses in the different
floater designs. The TLB Njord A is marginally stable without mooring lines, allowing it
to be towed to its final destination with additional water ballast. It has a combined
tower/floater steel mass of approximately 50% of the UMB-Hywind tower/floater steel
mass. In order to obtain stability, pre-stressed mooring lines are attached at two heights.
Njord B is a light weight construction with tower/floater steel mass about one third of the
UMB-Hywind tower/floater steel mass. The first wave tank test was conducted at the
NTNU/MARINTEK MCLab in Trondheim, Norway. The three models were tested with
regular waves corresponding to full scale waves with wave heights up to 30 m.
The experimental data are to be compared with numerical analysis in ANSYS and
3Dfloat, and will hopefully be useful for development of other computational tools as
well. During the IEA-OC3 project [1], it became clear that the access to experimental
data for floating wind turbines is very limited.
1. J. Jonkman et al: “Offshore Code Comparison Collaboration within IEA Wind
Task 23: Phase IV Results Regarding Floating Wind Turbine Modeling. To be
published at 2010 European Wind Energy Conference (EWEC) 20-23 April
2010, Warsaw, Poland
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SusPlan Characterisation and Modelling
of the Outer Hebrides Energy Resource
Malcolm Murray a (malcolm.murray@lews.uhi.ac.uk),
Edward Graham a (edward.graham@lews.uhi.ac.uk),
Neil Finlayson a (neil.finlayson@lews.uhi.ac.uk),
Sinclair Gair a (sinclairgair@btinternet.com)
Ruairi Maciver b (ruairi.maciver@cne-siar.gov.uk)
a Greenspace Research, Lews Castle College UHI, Stornoway, Isle of Lewis HS2 0XR,
Scotland
b
Comhairle nan Eilean Siar, Sandwick Road, Stornoway, Isle of Lewis, HS1 2BW,
Scotland
The development of the rich renewable energy resources of the Outer Hebrides
(Scotland) is both a challenge and an opportunity. In order to build least-cost action plans
for harvesting these resources for the good of the region and in support of a greener
Europe a model is required of the existing and future energy system, including the
infrastructure. In this paper we present such a model based on results from work within
the SUSPLAN project where the Outer Hebrides is one of the regional case studies.
SUSPLAN is a European Union 7th Framework Programme. The objective of the project
is to investigate the efficient integration of renewables into the future European energy
infrastructure. Future possibilities are mapped based on a bottom-up approach for
integrated renewable energy planning scenarios at regional, national, and European
levels.
The SusPlan methodology develops four future scenarios based on negative or positive
public attitudes, and slow or rapid technology development. Regional and trans-national
case studies inform the scenarios by providing detailed input characterising the energy
resource, existing and planned infrastructure, regional and national targets, load profiles
and barriers to integration. The resulting scenario data provide inputs into a recursive
modelling process based on pricing and least-cost deployment tools.
Several significant recent Westminster (UK) and Scottish Government planning consents
and decisions (Beauly-Denny infrastructure reinforcement, Eisgen windfarm, feed-in
tariffs, renewable heating initiative, offshore-wind farms) make substantial Hebridean
energy developments highly probable in the future. Certain barriers to integration and
future developments have therefore been lifted. In this paper we examine the possible
consequential impacts of these decisions and other key factors on the long-term
development of the Hebridean energy resource.
We characterise the energy resource, outline current and likely future Scottish and
Hebridean regional plans and scenarios, reflect on capital, skills and supply chain
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challenges and present a preliminary infrastructure model which will eventually be used
to derive least cost integrated investment pathways for energy developments in our
region.
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The Renewable Energy Research Conference Abstract
Greenhouse Gas Emissions of Wind Power – state of the art
Hanne Lerche Raadal a (hlr@ostfoldforskning.no),
Ingunn Saur Modahl a (ism@ostfoldforskning.no)
a Ostfold Research, Gamle Beddingvei 2B, N-1671 Kråkerøy, Norway
Ostfold Research is currently running the project Energy Trade and Environment 2020.
The project started in February 2009 and will last until August 2012. The objective of the
project is to contribute to a significant reduction in greenhouse gas emission from energy
generation and consumption, both nationally and internationally. This is expected to
happen as a result of:
making it more profitable to invest in new, renewable energy both in Norway as
well as internationally by using environmental information in the trading system
increased competitiveness and value adding in the Norwegian energy companies
related to sales of sustainable energy resources
creation of new knowledge within the fields of R&D as a platform for researchbased
teaching through the development of a research centre for sustainable
energy trade in the counties of Østfold and Akershus.
A PhD within this field will also be carried out as a part of the project.
One part of the project is to develop consistent models for documentation of the
environmental impact from the generation and use of electricity. The Life Cycle
Assessment (LCA) and Environmental Product Declaration (EPD) methodology will be
used as a basis for this environmental documentation. The project work has started with a
review and comparison of recent greenhouse gas (GHG) emission LCAs (Life Cycle
Assessments) of wind power.
The results from this work will present the state of the art for the environmental impact
category Global Warming Potential (GWP) for different wind power plants
(onshore/offshore, capacity factor, etc). The results will be presented as total greenhouse
gas emissions per kWh generated, divided into the different life cycle stages for the
power plants (infrastructure, operation etc) to present which life cycle stages are the most
important to the overall greenhouse gas emissions. The state of the art work for wind will
be finished during spring 2009, just in time for presentation at the The Renewable Energy
Research Conference
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Hybrid life-cycle assessment of wind power
Anders Arvesen (anders.arvesen@ntnu.no),
Edgar Hertwich (edgar.hertwich@ntnu.no)
The Industrial Ecology Programme, Norwegian University of Science and Technology
Despite the renewable nature of wind power, resource use and emissions occur in the lifecycle
of wind energy systems. A systematic evaluation of the life-cycle environmental
impacts of wind power can be valuable in several ways. First, it may provide
documentation of wind power’s ability to deliver low-carbon electricity. Second, it can
help in identifying system designs and strategies for maximizing the environmental
benefits of wind power. The primary objective of our work is to quantify and assess the
life-cycle resource use and emissions associated with the supply of 1kWh electricity from
wind energy conversion. A secondary objective is to perform a scenario analysis to study
economy-wide implications of existing projections for wind power development.
At its core, our research method is based on life-cycle assessment (LCA), a standardized
tool for assessing the environmental impacts generated throughout a product’s life-cycle.
Unlike most previous LCA research on wind power, we employ a hybrid LCA
methodology. That is, we use economic input-output analysis to complete our system,
thereby avoiding systematic truncation errors.
Results from the unit-based analysis show that while wind energy systems can be
regarded as material intensive, the energy and carbon embodied in one kWh of wind
power is low compared to fossil-based alternatives. Metals production is the major
contributor to life-cycle energy use and emissions, and the tower for the wind turbine is
the most important single component. These results do not conflict with findings from
previous LCA studies on wind power. Results are sensitive to assumptions regarding
capacity factor, the lifetimes of components, and recycling at the end-of-life. The
scenario analysis provides preliminary insights into how aggregated material flows of
wind power development relates to overall flows at the societal level. It also focuses on
the potential for wind power to contribute to targeted CO 2 emissions reductions, taking
into consideration life-cycle emissions and the anticipated expansion of wind power.
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Integrating renewable energy into the electricity market: A
case study on wind generation and spot prices in the Australian
National Electricity Market
Nicholas Cutler a (n.cutler@unsw.edu.au),
Hugh Outhred a (h.outhred@unsw.edu.au)
Iain MacGill a (i.macgill@unsw.edu.au)
a University of New South Wales, Sydney, Australia
This study aims to improve our understanding of renewable energy interactions in
electricity markets, using a case study of wind generation in the Australian National
Electricity Market (NEM). The case study explores the South Australian context where
average wind power penetrations have been exceeding 10% for the last couple of years.
The methodology is to assess the interaction of wind generation, electricity demand and
regional spot prices over one recent year of market data. The analysis is intended to
provide insights into the potential implications of a greater expansion of installed wind
generation in South Australia and across the other regions of the NEM under the recently
legislated expanded Renewable Energy Target. With the current installed wind
generation in South Australia, our results suggest that while electricity demand currently
has the greatest influence on spot prices, fluctuating South Australian wind generation
levels have a significant secondary influence. The results have relevance for other
electricity markets in the world where wind penetrations and other non-storable sources
of renewable energy are growing.
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POSTER PRESENTATIONS
Wind Power
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Title: Indian Ocean Phenomenon effecting wind business
Author: Altaf Tamboli
tambolialtaf@gmail.com
Indian Ocean Dipole (IOD) is the phenomenon of Indian Ocean itself and is affecting on the
wind stress and wind speed over the ocean for both onshore and offshore. The oceanic
phenomenon gives idea to wind resource specialist or meteorologist to predict or to project
the situation for wind speed and wind potential. Here we used five Meteorological met mast
data (actual data-wind speed, pressure and temperature) and try to correlate with Indian
oceanic phenomena. Annual and seasonal variation is correlated with Indian Ocean dipole. By
using the satellite data and nearest meteorological mast we can select the wind potential site
for wind energy sector. Also this paper outlined the wind variation with geographical
locations and useful tool for wind business. We can have the judgment for wind power
generation for particular year. In this paper we try to find out the correlation of wind data over
different location of India where we have existing the Wind Mast. Also this method may use
to find the suitable wind potential site which is now very important for competition in wind
sector.
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Fabrication Challenges in Mass Production of Support Structures
for Offshore Wind Energy Turbines
Daniel Zwick (daniel.zwick@ntnu.no),
Geir Moe (geir.moe@ntnu.no)
Department of Civil and Transport Engineering
Norwegian University of Science and Technology, Trondheim
The extremely ambitious political goals concerning extensive use of offshore wind energy
result in an intense demand of research and development in this field. As an example, round 3
in UK could mean a need to install several thousands of offshore wind turbines within the
next ten years. To be able to fulfil this goal, components for offshore wind farms has to be
produced by mass production techniques and within reasonably short fabrication time.
Where offshore wind turbines are planned to be installed in the intermediate water depth of
30-70m, support structures of a lattice towers type might be used. Lattice towers are
assembled from steel tubes, where legs and bracings are welded together in tubular joints.
Today’s lattice towers, known from the offshore oil and gas industry, are mainly fabricated by
manual welding due to the complex geometry of the joints. This results in time-consuming
and expensive fabrication of the support structure.
For the introduction of mass production of support structures for offshore wind turbines, the
knowledge from fabrication of lattice towers in the oil and gas sector has to be transferred as
well as new fabrication methods and structural designs has to be developed. A key factor for
mass production is the suitability of the joints for automatic welding as well as the ability of
the fabrication facilities to handle the size and weight of the structure in an effective way.
Several possible joint geometry concepts and fabrication methods will be presented and
discussed.
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ABSTRACTS
Solar Cells
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Crystalline-Silicon Photovoltaics: Still Necessary and Sufficient
Paul A. Basore
REC Technology US Inc, Foster City, California
At the first World Conference on Photovoltaic Energy Conversion in 1994, the presenter
dared predict the future cost and growth of PV in front of a packed auditorium. Now,
more than 15 years later, it is interesting to compare those predictions to what actually
happened. The price of PV systems using crystalline-silicon technology has come down
even faster than predicted, but the price of conventional electricity in the USA has not
increased as predicted. Consequently, the point in time when unsubsidized PV electricity
costs less than utility power for American homeowners having suitable roof space has
been pushed back from the originally predicted date of 2011. Instead, it now appears that
the cross-over will occur in California beginning in 2017. Until that time, some form of
public subsidy will continue to be necessary to sustain the rapid development of PV
electric power in the USA.
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Sistruc - a PC-program that calculates back diffusion during
directional solidification of Si.
Anne Lise Dons, SINTEF Metallurgi, Alfred Getz vei 2, N-
7465Trondheim. anne.l.dons@sintef.no
Sistruc is a PC-program that does step by step Scheil type calculation in Silicon with
planar, directional solidification. The composition of the solid at the interface is found
by
C(ss) = k C(liq)
Excess solute is mixed freely in the remaining liquid Here C(ss) and C(liq) are the
compositions of the solid and liquid phase, and k is the distribution coefficient. K is
temperature dependent if we have data, otherwise constant. Multi-component
calculations are possible too, but only until the temperature becomes so low that
ternary or quaternary phases precipitates.
It is also possible to include back diffusion of alloying elements into the already
solid part of the ingot, with temperature dependent diffusion coefficients and
equilibrium at the liquid / solid interface. The temperature is assumed to be equal to
the liquidus temperature at the solidification front.
Is it necessary to do back diffusion calculations, or is the Scheil equation good
enough? Figure 1 shows two examples of concentration profiles in Silicon, with 3ppm
Al + 3ppm Cu in the liquid before solidification. The profiles are:
- without back diffusion
- back diffusion during casting of an 100 mm high ingot during 5 hours
Figure 1 shows that it is necessary to consider back diffusion for fast diffusing
elements like Cu and Ni, but not for slow diffusing elements like Al.
3ppmAl 3ppmCu Scheill og 5h diffunder støp
100
10
ppm in ingot
1
0.1
0.01
ppmAl
ppmCu
Dif f5hAl
Dif f5hCu
0.001
0 20 40 60 80 100 120
Position in casting, bottom to top
Figure 1. Concentration profiles for Al and Cu without back diffusion and with back
diffusion during casting of an 100 mm high ingot during 5 hours.
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Distribution of Cu in directly solidified Si
Zhihong Jia a (zhihong.jia@material.ntnu.no),
Chiara Modanese a (chiara@material.ntnu.no),
Anne Lisa Dons b (Anne.L.Dons@sintef.no),
Otto Lohne a (otto.lohne@material.ntnu.no)
a Department of Materials Science and Engineering, Norwegian University of Science and
Technology, Alfred Getz vei 2b, N-7491 Trondheim, Norway
b SINTEF Materials and Chemistry, N-7465 Trondheim, Norway
Solar-grade polycrystalline silicon produced by metallurgical methods may play an
important role in solar cell production, because of the low cost and environment friendly
processes. However, the amount of impurities remaining in the materials has to be
controlled in order to obtain high efficiency solar cells. In this work the Cu concentration
was measured as a function of ingot height, and compared with the calculations from
Scheil equation without and with considering the parameters of diffusion in solid,
diffusion in liquid and solidification time. The results showed that there is evicence of
back diffusion depending on the casting conditions.
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The influence of Si 3 N 4 oxidation on the wetting between silicon
and Si 3 N 4 -coated substrates
Ingvild Brynjulfsen a (ingvild.brynjulfsen@material.ntnu.no),
Astrid Bakken a
Merete Tangstad a
Lars Arnberg a
a Norges teknisk-naturvitenskaplige universitet
Crucibles for directional solidification of silicon are often coated with Si 3 N 4 . One of the
purposes is to ensure that the ingot is released from the crucible. It is therefore important
that the silicon does not wet the crucible during melting.
Si 3 N 4 -coated SiO 2 -substrates have been fired in different atmospheres and temperatures
leading to varying oxygen levels in the coating. The wettability, between silicon and
Si 3 N 4 -coated substrates with varying oxygen levels, were further investigated with the
sessile drop method. The sessile drop experiments were performed with a holding
temperature of approximately 50°C and 150°C above the silicon liquidus. It was found
that a high oxygen content in the coating led to enhanced non-wetting. Wetting angles
around 100° were achieved with oxygen concentrations higher than 14 wt.%. In contrast,
oxygen levels around 2 wt.% resulted in angles around 60°. Deoxidation and infiltration
of the coating occurred during the experiments. At high temperatures, this reaction rate
increased significantly leading to a penetration of the coating.
Wetting angle vs. oxygen concentration
110
Final wetting angle (°)
100
90
80
70
60
50
0 5 10 15
Oxygen concentration (w t. %)
Air, 900°C, 2h
Nitrogen, 900°C, 2h
Argon, 900°C, 2h
Air, 1100°C, 0.5h
Air, 1100°C, 4h
Figure 1 – Wetting angle as a function of oxygen concentration in coating.
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Subject : SOLAR CELLS
Sub-heading: Silicon for solar cells
Preferred presentation format: Oral
High Temperature Electrochemical Refining of Silicon
Espen Olsen a (espen.olsen@umb.no)
Sverre Rolseth b (sverre.rolseth@sintef.no)
a Norwegian University of Life Sciences, N-1432 Ås, Norway
b SINTEF Materials and Chemistry, N-7465 Trondheim, Norway
Objective
Electrochemical refining of aluminium is performed industrially in the so called Hoopes-process
where metllurgical grade Al is alloyed with Cu at 750°C to give a heavy alloy which is polarized
anodically under a layer of a chloride and fluoride based electrolyte. On top of these, a layer of
pure Al is deposited cathodically, completing a three-layer stack. The process yields a product
with purity in the range 99.997 - 99.9999 wt% (6N). If Si may be purified to the same level as Al
in a similar three-layer electrochemical process above the melting point of Si (1412°C), it may
fully satisfy the requirements for photovoltaic purposes. The objective of the reported work has
been to investigate if the three-layer principle may be used to purify silicon and in particular
study the purification of individual contaminants. The laboratory scale used does not provide the
physical- or time scale needed to acheive full 6N purity, however, fundamental studies have been
performed with success.
Methodology
To diminish artefacts related to small scale, a large laboratory reactor was constructed, containing
on the order of 10 kg material. The performance of the purification process with regards to
selectivity of individual contaminants was studied systematically. Experiments were performed
on the order of 24 hours of continous operation. Mass balances of impurities were calculated
based on analyses of construction materials, anode alloy, electrolyte and purified Si. Upon
completion of the experiments, cell autopsies were performed in order to study the performance
of the construction materials as well as the behaviour of the three individual layers and efficiency
of the overall process.
Results
High temperature electrorefining of metallurgical Si by in the molten state was demonstrated in a
large laboratory scale reactor with current efficiencies above 90%. Purified Si was produced on
the order of kilograms. As expected from the principle, elements more electronegative than Si
tended to accumulate in the electrolyte whereas elements less electronegative was retained in the
bottom alloy charge. Purified Si was deposited at the top. The content of most transition metals
as well as phosphorous (P), approached 1 ppmw in the purified metal. The content of Al and Cu
was somewhat higher (100ppmw) which can be be attributed to the scale of the experiments. A
high grade of purification is expected in larger, industrial scale reactors also for these elements.
Boron, as the single element, was found not to be subject to electrochemical purification.
Thermodynamic studies attributed this to fundamental properties of this element. However,
electrocatalyzed precipitation reactions involving borides have been studied and may be
performed in parallell in a common, industrial reactor enabling purification also for boron.
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Constitutive modelling of solar-grade silicon multicrystals at
high temperatures
Julien Cochard a (julien.cochard@ntnu.no),
Sylvain Gouttebroze b (sylvain.gouttebroze@sintef.no),
Mohammed M’Hamdi b (mohammed.mhamdi@sintef.no),
Zhiliang Zhang a (zhiliang.zhang@ntnu.no)
a NTNU Structural Engineering, R. Birkelands vei 1a, NO-7491 Trondheim, Norway
b SINTEF Materials and Chemistry, P.B. 124 Blindern, NO-0315 Oslo, Norway
Solar-grade silicon (SoG-Si) ingots produced by directional solidification exhibit a
multicrystalline nature that makes their mechanical analysis complicated to perform.
Silicon is brittle below 600 C approximately. Plastic deformation proceeding by
dislocation generation and multiplication happens at high temperatures only. Predicting
the amount of plastic deformation in a SoG-Si multicrystal can be of high interest since
dislocations have a deleterious effect on solar cell efficiency.
The constitutive models used until now to analyze the stress field evolution in SoG-Si
ingots assume the material to be a continuum, homogeneous single crystal [1-3]. This
approach provides with the thermally-induced, macroscopic stresses. However, the
multicrystalline nature of directionally solidified ingots leads to additional, mesoscopic
stresses owing to kinematic compatibility requirements at the grain boundaries [4, 5].
Finally, the presence of inclusions and impurities in SoG-Si implies stress peaks on a
microscopic scale [6, 7].
We introduce in this work a novel constitutive model for silicon materials able to account
for complex thermo-mechanical loading paths and the subsequent stress and dislocation
density evolutions.
We apply this constitutive model to the 3D simulation of 3-point and 4-point bending
tests of SoG-Si multicrystalline bars at high temperatures. The stress and strain
distributions are compared to the case of monocrystals.
[1] O.W. Dillon, C.T. Tsai, R.J. De Angelis, J. Appl. Phys. 60, 1784 (1986)
[2] Y.K. Kim, R.J. De Angelis, C.T. Tsai, O.W. Dillon, Acta Metall. 35, 2091 (1987)
[3] M. M’Hamdi, E.A. Meese, H. Laux, E.J. Øvrelid, Mat. Sci. Forum 508, 597 (2006)
[4] F. Barbe, L. Decker, D. Jeulin, G. Cailletaud, Int. J. Plast. 17, 513 (2001)
[5] G. Cailletaud, K. Sai, S. Forest, Mech. Mater. 38, 203 (2006)
[6] J. Cochard, S. Gouttebroze, S. Dumoulin, M. M’Hamdi, Z.L. Zhang, 24 th EUPVSEC, Hamburg (2009)
[7] M. M’Hamdi, S. Gouttebroze, 24 th EUPVSEC, Hamburg (2009)
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A study of hardness indentations on a monocrystalline silicon wafer as means to
understand more about the material removal process in wire sawing
by
Bjørnar Espe and Otto Lohne
Institute of Materials Science and Engineering
NTNU
Trondheim, Norway
Abstract
Silicon solar cells are produced from wafers that have been wire sawn from mono- or
multicrystalline blocks. The wire sawing process has a high complexity and many parametres
may influence the speed of sawing and the quality of the wafer surface. It is generally
accepted that the production of kerfs during sawing is caused by the indentation of rolling SiC
particles. The mechanisms by which the indentations produce cracks and chips are believed to
have much in common to ordinary hardness tests. Our results are from Vickers and Knoop
testing of a monocrystalline (001) silicon surface. The measured hardness, lengths of cracks,
amount of chipping and shape of chips vary with the orientation of the indentor diagonal
relative to the crystallographical directions. The results are explained by taking the phase
changes during indentation and later stress release into consideration. These results differ to
some extent from the explanations obtained by treating silicon as a completely brittle material.
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Enhancing the performance of photovoltaic devices
via the application of luminescent materials
B.S. Richards 1 , B.C. Rowan 1 , D. Ross 1 , E. Klampaftis 1 , L.R. Wilson 1 , S. Ciorba 2 ,
N. Robertson 3 , A.C. Jones 3
1 School of Engineering & Physical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS, UNITED KINGDOM
2 Dipartimento di Chimica Fisica, Università Ca' Foscari di Venezia, 30123 Venezia-Mestre, ITALY
3 School of Chemistry, University of Edinburgh, Edinburgh, EH9 3JJ, UNITED KINGDOM
There are many ways in which luminescent materials can be applied to photovoltaic (PV) devices
and modules in order to enhance the conversion efficiency and/or spectral response [1]. In this
paper we will present results from four areas, which have resulted from several collaborative
research projects that include rare-earth containing luminescent materials.
Firstly, luminescent solar concentrators (LSC) present an exciting opportunity to reducing the cost
of solar electricity by replacing expensive semiconductors with large area glass or polymeric sheets
to harvest the solar radiation and waveguide this to long, thin, high-efficiency solar cells at the edges
of the sheet [2]. Research challenges in this area include: the development of luminescent materials
i) with a large Stokes shift to avoid re-absorption losses, and ii) the ability to emit in the nearinfrared
(NIR), closely matching the bandgap of silicon. LSC sheets produced in Edinburgh
utilising a Eu 3+ -containing compound in a PMMA host have exhibited fluorescence quantum yields
(FQY) of 85% and a Stokes shift of several hundred nanometers [3]. Further results will be
presented on Yb 3+ - and Nd 3+ - containing complexes that emit in the NIR, as well as the effect on
FQY of the host polymer.
Second, we have recently luminescent down-shifting (LDS) layers can be incorporated into the
native encapsulaion layer present in the majority of PV modules, while maintaining a high FQY [4].
There is also a significant opportunity here for rare-earth compounds and first results will be
presented on both silicon and cadmium telluride (CdTe) PV modules.
Thirdly, down-conversion (DC) layers promise a much greater advantage than LDS layers since
the former are defined as having a FQY > 100%. For PV, the practical goal is to achieve good
absorption of 300-500nm light and then maximize the FQY of an emitter (e.g. Yb 3+ or Nd 3+ ) in the
NIR to be as close to 200% as possible. Many research challenges remain, both to meet this goal,
but also to not undo the decades of research that has gone in the opto-electronic optimization of PV
devices.
Fourthly, up-conversion (UC) layers offer the potential of harnessing sub-bandgap light that is
otherwise transmitted through the PV device. Given the strong dependence on excitation intensity,
this tends to be best suited towards concentrating PV systems. Previous UC results by the author
have resulted in the achievement of an external quantum efficiency (EQE) of 3.4% occurring at 1523
nm with a silicon solar cell, via NaYF 4 :Er3 + phosphors doped into a rear polymeric layer [5].
References:
[1] B.S. Richards, Solar Energy Materials & Solar Cells 90 (2006) 2329–2337.
[2] B.C. Rowan, L.R. Wilson, B.S. Richards, IEEE Journal of Selected Topics in Quantum Electronics 14 (2008) 1312-
1322.
[3] O. Moudam, B.C. Rowan, M. Alamiry, P. Richardson, B.S. Richards, A.C. Jones, N. Robertson, Chem. Commun.,
2009, 6649–6651.
[4] E. Klampaftis, B.S. Richards, Progress in Photovoltaics (accepted for publication).
[5] B.S. Richards, IEEE Trans. Elec. Dev 54 (2007) 2679-2684.
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Submitted for publication in Proceedings of Renewable Energy Research Conference,
Trondheim, Norway, 7 - 8 June, 2010.
The Need for Long-Term and Accelerated Climate Exposure and
Durability Testing of New Solar Cell Materials and Systems
Bjørn Petter Jelle ab* , Knut Noreng a , Berit Time a and Arild Gustavsen c
a Department of Materials and Structures,
SINTEF Building and Infrastructure, Trondheim, Norway.
b Department of Civil and Transport Engineering,
Norwegian University of Science and Technology (NTNU), Trondheim, Norway.
c Department of Architectural Design, History and Technology,
Norwegian University of Science and Technology (NTNU), Trondheim, Norway.
*Corresponding author: E-mail: bjorn.petter.jelle@sintef.no, Phone: 47 73 59 33 77
New Solar Cell Materials and Climate Exposure Factors
As nanotechnology is applied and new solar cell materials and systems are being developed, there
arises a need to carry out extensive testing of their ability to withstand long-term climate
exposure with satisfactory durability of several crucial properties. The materials and systems have
to resist several large and varying climate exposure factors (Fig.1, left), i.e solar radiation
(UV-VIS-NIR), ambient infrared (IR) heat radiation, high and low temperatures, temperature
changes/cycles, water (e.g. moisture and wind-driven rain), physical strains (e.g. snow loads),
wind, erosion (also from above factors), pollutions (e.g. gases and particles in air),
microorganisms and time for all the factors above to work.
Building Integrated Photovoltaics (BIPV)
The developed solar cell materials and systems may beneficially be implemented into a building’s
exterior climate screen envelope, i.e. BIPV (Fig.1, middle). A BIPV system then also has to fulfil
the requirements of a building envelope vs. the different climate exposure factors, e.g. rain, air
and wind tightness and various building physical aspects like heat and moisture transport.
Acceleration Factors and Evaluation Before, During and After Ageing
Acceleration factors are calculated in order to estimate the ageing time in the laboratory apparatus
for the accelerated climate ageing with respect to a requested lifetime, where important factors
are ultraviolet (UV) radiation, temperature, wind-driven rain and freezing/thawing cycles.
Various properties of the solar cell materials and systems have to be tested before, during and
after the accelerated climate ageing, e.g. solar cell open circuit potential, short circuit current,
maximum output power, fill factor (FF), efficiency, different mechanical properties and any
chemical changes (Fig.1, right).
An example:
0.35
polymer + oxygen
-C-C-C-C-C- + O
2
Absorbance ( log10(1/T) )
0.30
0.25
0.20
0.15
0.10
0.05
PP
QUV
Fresh
Aged QUV 1 week
Aged QUV 2 weeks
Aged QUV 4 weeks
Aged QUV 7 weeks
Aged QUV 12 weeks
Aged QUV 31 weeks
Aged QUV 38 weeks
oxidized polymer
O
-C-C-C-C-C
H
0.00
2000
1950
1900
1850
1800
1750
1700
1650
1600
1550
1500
Wave Number (cm -1 )
Fig.1.
Buildings experience various and changing climate conditions throughout their lifetime (left, photo: Samfoto). Examples of
BIPV systems (middle, Solarcentury). Accelerated climate ageing and subsequent FTIR analysis during the ageing period
depicting an oxidation of the polymer (right).
Conclusions
New materials and solutions developed within photovoltaics and nanotechnology need to be
tested with respect to their performance and long-term stability vs. climate exposure, which may
readily be carried out in accelerated climate ageing experiments in the laboratory.
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Renewable Energy Research Conference 2010 34

The Centre for Renewable Energy
NTNU - SINTEF - IFE
SUN TRACKING SYSTEM DIRECTLY CONTROLLED BY SOLAR PANELS
Habtamu B. Madessa.*, Joakim R. Flesvik, Svein I. Malde, Atle Meistad, Per Hveem, Ole J. Nydal
Department of Energy and Process Engineering, Norwegian University of Science and
Technology,
Kolbjørn Hejes vei 1A, 7491 Trondheim, Norway
Background
The amounts of energy exploited from solar concentrating systems depend upon the
exposure of the solar concentrator towards the sun. As the sun's position changes
throughout the day, the solar concentrating unit must be adjusted so that it is always
focused towards the sun. Sun-tracking systems are used to ensure the solar collector to
receive the maximum possible solar irradiation at all times and increases the performance
of the overall solar energy conversion. The most important factors on the design and
selection of sun tracking unit are the accuracy of the tracker to direct the solar
concentrator towards the sun, the cost of the tracker, its simplicity and maintainability.
There are different types of commercially available solar trackers for different
applications. The tracking systems are generally electro mechanical and uses light sensor
and programmed micro controller.
Objective
The objective of the work is to investigate the performance of a simple and direct type
single axis tracking system which is controlled by shading effects on two solar panels.
Methodology
Two equal size panels are connected directly to the tracking motor, but with opposite
polarities of each other. A plate placed between the PV panels produces a shading effect.
When the sun is exactly in focus of the solar collector, the two panels are illuminated by
the sun rays at the same time. The potential difference across the tracking motor becomes
zero and solar concentrator becomes on stall condition.
When the sun moves and the rays are not parallel to the vertical plate, shadow will cast
partially or completely on one of the panels. This time the panel that is facing towards the
sun/or illuminated by the sun will produce a higher voltage. This produce a voltage
difference across the motor and the motor will rotates in direction to reduce the shadow
and finally it ensures that both panels are perpendicular to the sun rays.
Result
The tracking error was measured during the test in the sun. The results indicate the
tracking error to within one degree. The tracking system is characterized by simple, low
maintenance requirements and ease installation and operation. It is particularly suitable
for tracking of small scale systems which are out of the reach of the electric grid.
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Renewable Energy Research Conference 2010 35

The Centre for Renewable Energy
NTNU - SINTEF - IFE
An Investigation of the opportunity to Recover Radiation
Waste Heat by the Means of Thermoelectricity
Marit Takla a , Signe Kjelstrup a,* , Leiv Kolbeinsen b
and Nils Eivind Kamfjord b
a Department of Chemistry, Norwegian University of Science and Technology, NO7491
Trondheim
b Department of Materials Science and Engineering, Norwegian University of Science and
Technology, NO7491
* Corresponding author: signe.kjelstrup@chem.ntnu.no, tel: +47 73594179
We investigate the opportunity for recovering of radiation waste heat by means of
thermoelectricity. The focus is the casting area at the silicon plant of Elkem
Salten where the liquid silicon is the source of radiation. Silicon dioxidecontaining
fume is escaping to the surroundings during casting. We examine the
possibility for running a suction fan on power generated by thermoelectric
devices. We look at one wall mounted in the casting area which heats during
casting, and we examine the possibility for using commercially available
thermoelectric devices to convert this heat into electricity. We found that
thermoelectric devices based on bismuth telluride would be convenient for the
intended application. We have calculated the minimum area of thermoelectric
devices needed to generate enough power to run a suction fan, P fan . We based
our calculations on the thermoelectric module HZ-20 from Hi-Z Technology Inc.
(USA). The area needed is found to depend highly on the temperature difference
over the module. An area of 24m 2 is needed at a T of 100 ºC while at a T of
200 ºC is the required area 7m 2 . As the total wall area is 40.5 m 2 will it be
possible to generate enough power to run a suction fan assuming that 100 ºC <
T < 200 ºC.
Senterforfornybarenergi Side1av1
Renewable Energy Research Conference 2010 36

The Centre for Renewable Energy
NTNU - SINTEF - IFE
Atomic layer deposition of copper based oxides for use in PV
applications
Mari Alnes a (mari.alnes@smn.uio.no), Helmer Fjellvåg a
(helmer.fjellvag@kjemi.uio.no) and Ola Nilsen a (ola.nilsen@kjemi.uio.no)
a Department of Chemistry, Centre for Materials Science and Nanotechnology (SMN), University
of Oslo (UiO)
There is a demand for new materials and new techniques for production of materials used in
solar cells. There are numerous challenges, such as finding a good p-type transparent conducting
oxide [1]. In 1997 Kawazoe et al. reported on the CuAlO 2 material as a suitable transparent p-
type conductor [2]. There are also other possible candidates that contain copper [1]. Good control
of stoichiometry of the material and ability to deposit uniform and pin hole free thin films are
crucial for optimal performance for the PV applications. Atomic layer deposition (ALD) is a
suitable thin film technique fulfilling these requirements [3]. The ALD technique is based on
self-limiting chemical reactions between gas phase precursors and functional groups on a surface.
The technique enables control of growth down to an atomic layer by sequential pulsing of the
reactants. The ALD technique also enables deposition at relatively low temperatures, which is
important to prevent dopant diffusion.. The inherent control of the chemical process makes the
process suitable for depositing of complex oxides and doped materials [4]. The self-limiting
nature enables deposition of uniform films on 3D structures like nanowires and carbon nanotubes
[5].
We have successfully deposited thin films of copper oxide by ALD using copper(II)
acetylacetonate and ozone as precursors. The growth rate was found to be 0.038 nm/cycle within
the temperature range 140 – 230 ºC. The films have been analyzed by x-ray reflectometry, atomic
force microscopy, and electronic resistivity by 4 point probe measurements.
We have also performed preliminary work on deposition of thin films in the CuO - Al 2 O 3 system
using trimethyl aluminum and ozone as the aluminum source. The results indicate that we have
good control of the film composition.
1. Sheng, S., G. Fang, C. Li, S. Xu and X. Zhao, Phys. Status Solidi A, 203, (2006), 1891.
2. Kawazoe, H., M. Yasukawa, H. Kyodo, M. Kurita, H. Yanagi and H. Hosono, Nature,
389, (1997), 939.
3. Ritala, M. and M. Leskelä, Chapter 2 Atomic Layer Deposition, in Handbook of thin film
materials, H.S. Nalwa, Editor, 2002, Academic Press: San Diego, 103-108.
4. Nilsen, O., E. Rauwel, H. Fjellvåg and A. Kjekshus, J. Mater. Chem. , 17, (2007), 1466.
5. Knez, M., K. Nielsch and L. Niinistö, Adv. Mater., 19, (2007), 3425.
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Renewable Energy Research Conference 2010 37

The Centre for Renewable Energy
NTNU - SINTEF - IFE
Light trapping in very thin, crystalline silicon solar cells
Erik Stensrud Marstein (erik.stensrud.marstein@ife.no), Josefine Helene
Selj, Jo Gjessing, Håvard Granlund, Solveig Rørkjær and Sean Erik Foss
Solar Energy Department, Institute for Energy Technology (IFE)
By far the largest fraction of solar cells manufactured today is made from crystalline
silicon wafers. In order to reduce the cost of solar electricity produced by such solar cells
further, there is a drive towards the use of ever thinner wafers. Several processes able to
produce large area crystalline substrates with thicknesses of well below 100 m have
been presented. However, as the thickness of a silicon wafer is reduced, losses in current
and efficiency due to optical transmission rapidly become large. As a result, structures
allowing for efficient trapping of light within the solar cell are required.
In this presentation, recent results from the IFE solar cell laboratory in this field
will be presented. Several light trapping structures have been modelled, manufactured
and characterized, including photonic crystal structures and nanostructured materials
optimized for use as anti reflection coatings and rear side reflectors.
Senterforfornybarenergi Side1av1
Renewable Energy Research Conference 2010 38

The Centre for Renewable Energy
NTNU - SINTEF - IFE
Solar Cells based on low temperature crystallization of a-Si;H on aluminium
foil substrate: Structure & Characterization
Alexander Ulyashin a , Heidi Normark c , Frode Tyholdt a , Kjell Stenstadvold b ,
Merete.Hallenstvetand b , Ingeborg Kaus c , and Massoud Javidi b .
a SINTEF Materials and Chemistry, Forskningsveien 1, NO-0314 Oslo, Norway
b Norsk Hydro ASA, Drammensveien 250, NO-0240, Oslo, Norway
c SINTEF Materials and Chemistry, NO-7465 Trondheim, Norway
This work reports on novel aluminium induced silicon lateral nano or μ-crystallization of
sputtered amorphous silicon on thin aluminium foil. The conventional method is based on layer
exchanged or metal-silicide assisted lateral polycrystalline formation aiming at producing large
grain sizes compared to the film thickness. In both methods a low-temperature crystallization of
thin Si layers sputtered at room temperature on Al substrates takes place. The advantage of the
proposed method is that the production of nano grains removes the existing challenge of
producing larger grains of the polycrystalline silicon. An additional advantage is the removal of
the etching step which is required for the residual Al on the surfaces of the sample after annealing
of Al/Si stack as in the layer exchange method.
Raman spectra and TEM images of thin Si layer directly crystallised on Al substrate are shown
below. From these figures it can be concluded that thin Si layer crystallised on Al substrate
consist of nanocrystalline Si grains in amorphous silicon regions upon a direct AIC process.
Si/Al layer
Partly crystalline areas
Some regions were partly crystalline and partly amorphous
Materials and Chemistry
13
Intensity (a.u).
14000
12000
10000
8000
6000
4000
2000
550 0 C ITO/n+ a-Si:H(200nm)/p-a-Si:H (1 µm)
550 o C,30 min, peak 517.8 cm -1
as deposited,peak 494.2 cm -1
550 o C,60 min, peak 521.4 cm -1
521 cm -1
0
400 450 500 550 600
Raman shift (cm -1 )
XTEM and Raman spectra images of Si layer crystallised on Al substrate.
Renewable Energy Research Conference 2010 39

The Centre for Renewable Energy
NTNU - SINTEF - IFE
Laser-based processes for production of high efficiency silicon
solar cells
Sean Erik Foss (sean.erik.foss@ife.no)
Solar Energy Department, Institute for Energy Technology (IFE)
Advanced solar cell designs are increasingly necessary as a means to improve the
efficiency of solar cells based on silicon wafers. This will often imply that processing
during fabrication of the cell is done locally in a given pattern. There are not many
methods for fast and robust local processing in an industrial setting that are good enough
today for high-efficiency solar cells. Here the laser comes in with several unique
properties. With the laser one may locally heat, locally remove material and locally
structure material which may enable and improve production of this type of solar cell at a
large scale. This presentation will go through some of the opportunities presented by the
laser in silicon wafer based solar cell production, as well as some examples of research
being done at IFE within this field.
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Renewable Energy Research Conference 2010 40

The Centre for Renewable Energy
NTNU - SINTEF - IFE
ZnO nanorod hybrid Organic/Inorganic Solar Cells and the
effect of surface modifications
C.C. Weigand a (Christian.weigand@iet.ntnu.no), D.J. Baker b
(dbaker@mines.edu) , J.M. Adamson b , C.G. Allen c , M.R. Bergren b , K.X.
Steirer b , D.C. Olson d , C. Ladam e , D.S. Ginley d , R.T. Collins b , and T.E.
Furtak b , H. Weman a
a Department of Electronics and Telecommunications, Norwegian University of Science
and Technology, NO-7491 Trondheim, Norway,
b Department of Physics, Colorado School of Mines, Golden, Colorado, USA
c Materials Science and Engineering, University of Arizona, Tucson, Arizona, USA
d National Renewable Energy Laboratory (NREL), Golden, Colorado, USA
and e SINTEF Materials and Chemistry, NO-7465 Trondheim, Norway
Solar power is a climate-friendly, renewable energy source, but as of today suffers from
high costs/kWh compared to fossil fuels, greatly due to high production and processing
costs for high-quality grade silicon. As an alternative approach, nanostructured hybrid
inorganic/organic solar cells are a promising candidate for achieving competitive prices
per kWh by utilizing low-cost materials and manufacturing processes. However, one of
the issues with these devices is the intercalation of the active polymer between the
inorganic nanostructures (e.g. nanowires) and reported efficiencies of such excitonic
hybrid solar cells are still very low. One approach to improving the performance is the
surface modification of the inorganic nanostructures to enhance not only intercalation of
the polymer, but also energy level offsets, carrier capture, and polymer morphology.
Here, we report on the fabrication of surface-modified hybrid inorganic/organic solar
cells using planar ZnO surfaces as well as ZnO nanowires as the inorganic acceptor and
poly(3-hexylthiophene) (P3HT) as the active organic polymer. The devices were
solution-processed in air and ZnO surfaces were modified using silane- and thiol-based
attachment schemes with octadecane- and phenyl-endgroups. Prepared devices were
characterized by scanning electron microscopy (SEM), Fourier Transform Infrared
Spectroscopy (FTIR), optical absorption, contact angles and I-V characteristics
measurements. FTIR and contact angle measurements showed that the ZnO surface was
covered with the different molecules using both attachment schemes and that the effects
of surface modification on the wetting properties increased with the nanostructure
morphology compared to planar ZnO surfaces. SEM images revealed improved polymer
intercalation over the control samples, when the ZnO nanowires were modified with
octadecane-endgroups. However, the current-voltage curves reveal a decrease in device
performance with surface modification, probably due to the modified band structure at
the donor-acceptor interface.
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Renewable Energy Research Conference 2010 41

The Centre for Renewable Energy
NTNU - SINTEF - IFE
Metal hydrides for photovoltaics
Trygve Mongstad a (trygve.mongstad@ife.no),
Smagul Karazhanov a , Charlotte Platzer-Björkman b ,
Arve Holt a , Jan-Petter Mæhlen a
a Institute for Energy Technology (IFE), Kjeller, Norway
b Uppsala University, Uppsala, Sweden
Many metal hydrides may find applications in future solar cell designs, because they
possess an open band gap. Many of the hydrides are based on cheap and abundant
elements, which is an important aspect when considering materials for photovoltaics.
Wide band gap metal hydrides may find applications as passivating anti-reflection
coatings or even as a transparent conductor. Small band gap hydrides can be used in thin
film solar cells or multiple junction cells.
We have done initial experiments with hydrides of magnesium and yttrium. Thin films
have been prepared using magnetron sputtering with a gas mixture of argon and
hydrogen. In this technique, called reactive sputtering, the hydrogen in the sputtering gas
reacts during deposition, and a hydride film can be formed in-situ. By using this process,
we avoid using additional hydrogenation steps that are usual in the preparation of hydride
films. Our experiments showed that we were able to prepare crystalline films of both
yttrium hydride and magnesium hydride.
Magnesium hydride is a wide band gap material with E g =5.6 eV, which makes the
material a candidate for a transparent conductor. However, under our deposition
conditions undesired metallic magnesium particles are formed within the magnesium
hydride thin film, and the films appear dark brown. Further attempts on synthesizing a
single phase thin film of Mg will be done future experiments.
Yttrium trihydride has a band gap of 2.63 eV, which may be suitable for transparent
conducting oxides as well as an absorber material for ultraviolet light. Our results yielded
transparent, black or metallic films of yttrium and yttrium hydride. We have strong
indications that the transparent phase is semiconducting, which makes it an interesting
material for future investigations on the application of metal hydrides for solar cells.
We acknowledge funding from the Norwegian Research Council through the
NANOMAT program.
Renewable Energy Research Conference 2010 42

The Centre for Renewable Energy
NTNU - SINTEF - IFE
Synthesis of FeS 2 for photovoltaic applications
Per Martin Rørvik* and Fride Vullum
Department of Materials Science and Engineering, Norwegian University of Science and
Technology, 7491 Trondheim, Norway
*per.martin.rorvik@material.ntnu.no
Iron pyrite (FeS 2 , E g = 0.95 eV) is of interest as a solar energy material due to its environmental
compatibility and its very high light absorption coefficient. It has for instance been
proposed to use pyrite in a p-i-n structure with pyrite as an extremely thin light-absorbing
intrinsic layer sandwiched between large gap p-type and n-type materials. Low-temperature
approaches for preparing pyrite are highly attractive because pyrite decomposes into Fe 1-x S
and sulphur at elevated temperatures. In this work we have used hydrothermal synthesis at
180-200 °C to prepare pyrite crystals and thin films. A single-source molecular precursor
containing both iron and sulphur, Fe[(C 2 H 5 ) 2 NCS(S)] 3 , was prepared from aqueous FeCl 3
and Na[(C 2 H 5 ) 2 NCS(S)] solutions. The formation of pure pyrite from this precursor was
enhanced by prolonged synthesis time and increased reaction temperature. The effect of
adding a cationic surfactant was studied. A major objective was to either avoid formation of
the marcasite polymorph of FeS 2 (E g = 0.34 eV) and greigite (Fe 3 S 4 , semimetallic) or convert
these phases into pyrite, as the lower band gaps will harm the photovoltaic performance. The
formation of thin films on glass and single-crystalline TiO 2 substrates is also reported.
Renewable Energy Research Conference 2010 43

The Centre for Renewable Energy
NTNU - SINTEF - IFE
Quantum dot density studies for quantum dot intermediate band solar cells
Sedsel Fretheim Thomassen (sedsel.thomassen@ntnu.no) 1 ,
Dayong Zhou (dayong.zhou@iet.ntnu.no) 2 , Stefano Vitelli (vitelli@stud.ntnu.no) 2 ,
Maryam Gholami Mayani (maryam.gholami@ntnu.no) 1 ,
Bjørn-Ove Fimland (bjorn.fimland@iet.ntnu.no) 2
and Turid Worren Reenaas (turid.reenaas@ntnu.no) 1
1
Department of Physics,
2
Department of Electronics and Telecommunications,
Norwegian University of Science and Technology (NTNU), NO-7491 Trondheim, Norway
Quantum dots (QDs) have been an active area of research for many years and have been
implemented in several applications, such as lasers and detectors. 1 During the last years, some
attempts have been made to increase the absorption and efficiency of solar cells by inserting QDs
into the intrinsic region of pin solar cells. 2 So far, these attempts have been successful in increasing
the absorption, but not the cell efficiency. There are probably several reasons for this lack of
efficiency increase, but we believe that one important reason is the low density of the implemented
QDs.
In this work, samples of single layer InAs QDs on n-GaAs(001) substrates have been grown by
molecular beam epitaxy (MBE) and we have performed a systematic study of how deposition
parameters affect the QD density. The aim is to achieve densities > 10 11 cm -2 . The nominal substrate
temperature (360 – 500 °C), the InAs growth rate (0.085 – 1 ML/s) and thickness (2.0 – 2.8 ML)
have been varied in a systematic way for two different deposition methods of InAs, i.e. continuous
deposition or deposition with interruptions. In addition, we have for the continuous growth samples
also varied the As-flux (0.5 – 6 10 -6 torr). Scanning electron microscopy (SEM) has been the main
characterization method to determine quantum dot sizes and densities, and atomic force microscopy
(AFM) has been used for evaluation of the quantum dot heights.
We find that the QD density increases with reduced growth temperature and that it is higher for
samples grown continuously than for samples grown with growth interruptions. The homogeneity is
also strongly affected by temperature, InAs deposition method and the As-flux. We have observed
QD densities as high as 2.5 10 11 cm -2 for the samples grown at the lowest growth temperatures.
1
S. M. Kim, in Review on recent development of quantum dots: from optoelectronic
devices to novel biosensing applications, San Jose, CA, USA, 2003 (SPIE), p. 423-430.
2
A. Marti, L. Cuadra, and A. Luque, in Quantum dot intermediate band solar cell, 2000,
p. 940-943.
Renewable Energy Research Conference 2010 44

The Centre for Renewable Energy
NTNU - SINTEF - IFE
POSTER PRESENTATIONS
Solar Cells
Renewable Energy Research Conference 2010 45

The Centre for Renewable Energy
NTNU - SINTEF - IFE
Distribution of Boron during Removal from Molten Silicon when Using CaO-SiO 2 Slags
Lars Klemet Jakobsson and Merete Tangstad
Department of Materials Science and Engineering, NTNU, NO-7491, Trondheim, Norway
E-mail: lars.klemet.jakobsson@material.ntnu.no, merete.tangstad@material.ntnu.no
Metallurgical grade silicon is the starting material for production of silicon for crystalline
silicon solar cells. This silicon has to be purified before it can be used for solar cells, and the
dominating purification process today is the Siemens process, which is an expensive and
energy demanding process. The silicon produced through this process has a purity of 9N (nine
nines), while the required purity level for crystalline solar cells is 6N. One promising method
for reaching this purity level with less cost and less use of energy is to refine metallurgical
silicon using a pyro-metallurgical approach. The main challenge with this approach is to bring
down the amount of boron and phosphorus to the required level.
This work is focusing on removal of boron by slag treatment of molten silicon, which is one
of the most promising methods for removal of this element. Boron is absorbed from the
silicon and oxidized when it goes into the slag in this method. The system will have to be kept
at reaction temperature for a certain time before reaching equilibrium, and there will be a
distribution coefficient of boron between the molten silicon and slag at equilibrium. The
amount of boron can therefore be brought down to the required level by using a certain
amount of slag and keeping the system at reaction temperature for a certain time. The
distribution coefficient and the rate of transport are important parameters to know in order to
quantify the ability of the slag to remove boron from molten silicon.
The rate of transport of boron from molten silicon into CaO-SiO 2 slags is investigated in this
work through several experiments. The slags have a CaO/SiO 2 ratio between 0.56 and 1.16
and the systems are kept at a reaction temperature of 1823 K. Both the time for the reaction to
reach equilibrium, and the distribution of boron between slag and silicon before and at
equilibrium is found. These results are important for a better understanding of boron removal
from silicon by slag treatment.
Renewable Energy Research Conference 2010 46

The Centre for Renewable Energy
NTNU - SINTEF - IFE
Effect of crystal and crucible rotations on global heat transfer
and melt convection during Czochralski silicon crystal growth
O. Asadi Noghabi a (omid.asadi@material.ntnu.no),
M. M’Hamdi a,b (mohammed.mhamdi@sintef.no)
M.Jomâa b (moez.jomaa@sintef.no)
a Norwegian University of Science and Technology, Trondheim, Norway
b SINTEF Materials Technology, Oslo, Norway
Melt convection plays a key role in the heat transfer and impurity transport in the
Czochralski process for single silicon crystals. Different driving forces affect the melt
flow inside the crucible, e.g., buoyant forces caused by thermal gradient in the melt,
thermocapillary forces caused by surface tension gradients, Coriolis and centrifugal
forces caused by crucible and crystal rotations. Numerical simulation is a useful tool for
studying the complex interactions between these driving forces.
The purpose of this study is to analyse the impact of crystal and crucible rotations on
the flow pattern and thermal field for a 6 in diameter silicon crystal. Melt flow was
assumed axisymmetric and a quasi-steady state approximation was adopted. A Number of
combinations for crystal and crucible rotations rates were applied at various crystal
positions and associated melt level heights. Other growth control parameters like pulling
rate and gas flow rate were kept constant. Consequences on the flow patterns were
studied for each position and rotation rates. Streamlines were analyzed inside the bulk
flow, near crucible wall, near melt free surface, underneath of melt crystal interface and
near the symmetric axis.
The crystal/melt interface shape was altered by changing rotation rates. Maximum
deflection and thermal gradient at the melt/crystal interface and heating power were
calculated for each set of rotation rates. It is shown that even though silicon melt is a low
Prandtl liquid, heat transfer and the temperature field are greatly affected by the flow
structure at high Grashof and Reynolds numbers. The numerical results show that it is
possible to find an optimized set of crystal and crucible rotation rates resulting in a
minimum interface deflection for a given puling rate.
Figure 1 – Temperature field and streamlines for
crystal
10 rpm
and
crucible
5rpm
.
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Renewable Energy Research Conference 2010 47

The Centre for Renewable Energy
NTNU - SINTEF - IFE
High temperature heat treatment of multicrystalline PV-silicon
A.R. Gallala a (aleksander.rise.gallala@gmail.com),
C. Modanese a (chiara@material.ntnu.no),
M. Di Sabatino b (marisa.di.sabatino@sintef.no),
L. Arnberg a (lars.arnberg@material.ntnu.no)
a Dep. Materials Science and Engineering, NTNU, Trondheim, Norway
b SINTEF Materials and Chemistry, Trondheim, Norway
This report presents an investigation of the role of oxygen in both solar grade-silicon
(SoG-Si) and electronic grade-silicon (EG-Si). The aim was to heat treat samples in order
to dissolve all oxygen precipitates present in the as-grown state and investigate the effect
on lifetime. Samples from three different ingot materials cast through directional
solidification were used. Heat treatments at the temperature of 1300°C in inert
atmosphere with subsequent quenching were performed. The impact on the concentration
of interstitially dissolved oxygen was investigated in five different vertical positions by
Fourier transform infrared red (FTIR) spectroscopy. Measurements of resistivity and
minority carrier lifetime before and after heat treatment were also performed.
An experimental set-up was established for the heat treatments. Comparison of the
material properties before and after heat treatment showed that the heat treatment had
several impacts. In all samples an increase of 20% of dissolved oxygen concentration
after heat treatment was observed. It was also confirmed that all materials had a
decreasing dissolved oxygen concentration with increasing ingot height, as observed
before the heat treatment.
The lifetime values for all the heat treated samples were measured to be lower than 0.1
s.
Present address: Dep. Materials Science and Engineering, NTNU, Trondheim, Norway
Marisa.di.sabatino@material.ntnu.no
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Renewable Energy Research Conference 2010 48

The Centre for Renewable Energy
NTNU - SINTEF - IFE
STRUCTURAL PROPERTIES OF GERMANIUM-DOPED
MULTICRYSTALLINE SILICON
G. Minozzi a (minozzi@stud.ntnu.no),
M. P. Bellmann b (martin.bellmann@material.ntnu.no),
L. Arnberg b (lars.arnberg@material.ntnu.no)
a Dipartimento di Tecnica e Gestione dei Sistemi Industriali, Università di Padova,
Stradella S.Nicola 3, 36100 Vicenza, Italy
b Institute for Materialteknologi, NTNU, Alfred Getz Vei 2, 7465 Trondheim, Norway
Presently, the efficiency of standard solar cells made from multi-crystalline silicon (mc-
Si) reaches values in the range of 16%. A main point for the achievement of higher cell
efficiencies is a significant improvement of the bulk material. Of particular relevance are
extended crystal defects such as dislocations, which are important recombination centres.
Therefore the reduction of the overall dislocation density should improve the
performance of the material. Previous results have shown that the dislocations nucleate
and multiply during crystal growth due to local stresses, which arise from differences in
the local thermal expansion. Especially, the formation of localized areas with very high
dislocation densities (up to 1*10 8 cm-2) are crucial, because these regions are particular
detrimental for the charge carrier lifetime and the material performance. A further
improvement of multi-crystalline material requires a substantial reduction of these bad
regions. The goal of the present investigation is to reduce the dislocation densities by
hindering the nucleation and motion of dislocations. Solid solution hardening by
impurities, which cause local strains, is a well known phenomenon in metals. Since
germanium is an electrically inactive element with high local strain in silicon due to the
larger size the effect on the dislocation multiplication has been studied here.
We have investigated different mc-Si materials which were intentionally doped with
germanium concentrations of up to 1% of weight. The influence of the germanium on the
distribution of oxygen, carbon and the dislocations was studied by Fourier Transform
Infrared Spectroscopy (FTIR) and PV-Scan.
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Renewable Energy Research Conference 2010 49

The Centre for Renewable Energy
NTNU - SINTEF - IFE
Reflection Reduction through Porous Textures on mc-Si
Wafers by Anodic Polarization in Aqueous KOH
Madhu Abburi a,b (madhu.abburi@norut.no),
Tobias Boström a (tobias@norut.no),
Ingemar Olefjord a (olefjord40@tele2.se),
Kemal Nisancioglu b (kemaln@material.ntnu.no)
a Norut Narvik AS, N-8504, Narvik, Norway
b Department of Materials Science and Engineering, Norwegian University of Science and
Technology, N-7491 Trondheim, Norway
Formation of light absorbing surface textures on silicon wafers is an important process
step in solar cell fabrication in order to reduce reflection and hence effectively transmit
incident light in to the cell. Commonly used wet chemical etchants to texture mc-Si
wafers have their clear disadvantages despite their widespread usage. Alkaline etchants
containing KOH or NaOH are strongly anisotropic. They are well suited for single crystal
(100) orientation wafers but not effective for mc-Si due to slow etching of (111) planes.
In contrast to alkaline etching, acidic etching with a mixture of aqueous solutions of HF-
HNO 3 -CH 3 COOH is isotropic. It forms uniform textures on mc-Si wafers. However, the
etch rate is hard to control at defects and grain boundaries and also solutions containing
HF are environmentally hazardous. In this paper, we present the formation of uniform
porous textures on mc-Si wafers by anodic polarization in aqueous KOH solution.
As-cut boron doped mc-Si wafers are chemically etched and thereafter anodically
polarised at various potentials in strong alkaline solutions. The effect of KOH
concentration, temperature, applied potential and exposure time on formation of textures
is studied. The exposed samples are analysed by X-ray photoelectron spectroscopy
(XPS), scanning electron microscope (SEM) and UV/Vis/NIR spectrophotometry.
At anodic potentials, the silicon surface is oxidised and passivated by forming an oxide
film. The thickness of the oxide increases with the potential. However, stability of the
oxide decreases with increasing the potential above oxygen evolution potentials. At high
potentials above 20V and at a high solution concentration and temperature, the oxide
starts to dissolve locally thereby initiating the pores. Pore density and propagation
increases along with the exposure time. Pre etching is carried out for 2 min at open circuit
potential (OCP) to remove the saw damaged layer prior to polarisation. By optimising the
etch parameters, uniform porous textures which resemble the textures formed by acidic
etchants are obtained with in a time frame of 5 min. Reflectance of the textured surfaces
are measured in the 350-1100 nm wavelength range and compared with the textures
formed by conventional alkaline and acidic etching methods. In comparison, the
reflectance is reduced by 50%. An average reflectance of 15% is achieved. In addition to
the experimental findings, a detailed etching mechanism is also presented.
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Inorganic photoluminescent films for the UV to Vis energy
conversion
Edita Garskaite a (edita.garskaite@umb.no),
Espen Olsen a (espen.olsen@umb.no)
a Dep. of Mathematical Sciences and Technology, University of Life Sciences (UMB),
P.O. Box 5003, Drøbakveien 31, NO-1432 Ås, Norway
Dye Sensitized Solar Cells (DSSCs) are photoelectrochemical devices that
generate electricity from light without any permanent chemical transformation. One of
the major factors currently limiting DSSCs performance is a limited spectral response of
the sensitizer dye which acts as light harvesting component. Also, exposure to UV
radiation can be deleterious for DSSCs since photooxidation of the sensitizing dye and
irreversible degradation of the electrolyte occurs [1,2].
To improve the spectral response of solar cells to short-wavelength light, the use
of luminescence down-shifting layers has been proposed. Rare earth (RE) doped oxide
materials have characteristic luminescence properties such as sharp and intense emission
bands, long radiative lifetimes and high internal quantum efficiency [3,4].
We report herein on deposition of RE doped TiO 2 /Y 2 O 3 films on FTO glass substrates
by doctor blading and spray-coating techniques (Fig.1). The influence of colloidal paste
and sol composition using different polymeric binders on the morphology and
microstructure of deposited films will be addressed. Annealing temperature, porosity and
doping concentration effect on the TiO2/Y 2 O 3 optical transmittance and reflectance
spectra will also be discussed.
Figure 1. Surface and cross sectional SEM images of TiO 2 doped Eu 2 O 3 (2%) (a)) and
TiO 2 (b) (films annealed at 450 o C).
[1] M. Gratzel, Acc. Chem. Res., 42 (11), 2009, 1781.
[2] W.M. Campbell, A.K. Burell, D.L. Officer, K.W.Jolley, Coord. Chem. Rew. 248, 2004, 1363.
[3] E. Klampaftis, D. Ross, K.R. McIntosh, B.C. Richards, Sol. Energy Mater. Sol. Cells, 93,
2009, 1182.
[4] J.Liu, Q. Yao, Y.Li, Appl. Phys. Lett., 88 (17), 2006, 173113.
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XPS, TEM and DFT studies of TCO (ITO, ZnO) thin films and TCO/Si interfaces
S.Diplas 1 (Spyros.Diplas@sintef.no), O.M.Løvvik 1 (OleMartin.Lovvik@sintef.no),
H.Nordmark 2 (Heidi.Nordmark@sintef.no), D.M Kepaptsoglou 3
(d.m.kepaptsoglou@fys.uio.no), Q.M. Ramasse 4 (qmramasse@superstem.org), C.
Ladam 2 (Cecile.Ladam@sintef.no), J.Moe Graff 1 (JoachimMoe.Graff@sintef.no),
F.Tyholdt 1 (Frode.Tyholdt@sintef.no), J.C. Walmsley 2 (John.Walmsey@sintef.no),
R. Fagerberg 2 (Ragnar.Fagerberg@sintef.no), B.S. Tanem 2 (Bjorn.S.Tanem@sintef.no),
A.E.Gunnaes 3 (eleonora@fys.uio.no) and A.Ulyashin 1 (Alexander.Ulyashin@sintef.no)
1 SINTEF Materials and Chemistry, Forskningsvn 1, NO-0314 Oslo, Norway
2 SINTEF Materials and Chemistry, Høgskoleringen 5, NO-7465 Trondheim, Norway
3 Dept of Physics, University of Oslo, P.O. Box 1048 Blindern, NO-0316 Oslo, Norway
4 SuperSTEM Laboratory, STFC Daresbury, Keckwick Lane, Warrington, WA44AD, UK.
Transparent conducting oxides (TCO) like In-Sn oxide (ITO) and ZnO are widely used in
solar cells, both as antireflection coatings and transparent conducting electrodes, due to
their attractive combination of electrical conductivity and transparency to visible light. In
heterojunction photovoltaic systems, interfaces are strongly influenced by processing
conditions and they play an important role since a significant and increasing proportion
of charge carrier loss is due to interfaces as film thickness decreases. We used x-ray
photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and electron
energy loss spectroscopy (EELS) to study ITO and ZnO films produced by e-beam,
magnetron sputtering and pulsed laser deposition as well as the TCO-Si interface. With
XPS we probed the composition, chemical state and the electronic structure of the films
and the Si-ITO interfaces at high energy resolution. With TEM/EELS we studied the
microstructure of the films and its dependence on processing parameters as well as the
morphology and composition of the ITO-Si interface at high spatial resolution. Using
density functional theory various atomistic models of ITO at the GGA level as well as a
periodic model of the ITO/Si interface, were constructed providing detailed information
about the local environment at the interface. DFT based molecular dynamics was
performed, showing how metal-oxygen bonds were broken on behalf of silicon-oxygen
bonds. Our combined theoretical and experimental results support the experimentally
established fact that degenerated n-type semiconductor ITO being deposited on n-type Si
can be used for fabrication of high-efficiency ITO/n-Si heterojunction solar cells.
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Energyconversion materials for PV applications
P-A. Hansen a , H. Fjellvåg, O. Nilsen and T. Finstad b
a Department of Chemistry, b Department of Physics, Centre for Materials Science and Nanotechnology
(SMN), University of Oslo, P.B. 1033 Blindern, 0315 Oslo, Norway.
p.a.hansen@kjemi.uio.no
Silicon solar cells are unfortunately not perfect. Two major mechanisms for losses in
present solar cells are thermalization of high energy photons and transparency to near
infraread (NIR) photons. The present work focuses on utilization of the NIR photons by
up conversion processes. Up conversion will be achieved by using a combination of
different rare earth ions such as (Pr, Nd, Dy, Er, Yb) [1, 2]. We here report on deposition
of thin films of Yb 2 O 3 by the atomic layer depositon (ALD) technique. The technique
enables deposition of materials with control of thickness at the atomic level and at
relatively low temperatures. This enables construction of layered materials where the
interplay of different rare earth elements may be investigated. The same materials have
also been deposited by spin coating for comparison.
The optical properties of these materials have been characterized by spectrophotometry
and photo luminescence.
1. Shalav, A., B.S. Richards, and M.A. Green, Luminescent layers for enhanced
silicon solar cell performance: Up-conversion. Solar Energy Materials and Solar
Cells, 2007. 91(9): p. 829-842.
2. Trupke, T., et al., Efficiency enhancement of solar cells by luminescent upconversion
of sunlight. Solar Energy Materials and Solar Cells, 2006. 90(18-19):
p. 3327-3338.
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PULSED LASER ABLATION AND DEPOSITION OF SILICON
Seong Shan Yap 1,* , Alesya Viktorovna Salomatova 1 , Cécile Ladam 2 , Øystein Dahl 2 and Turid
Worren Reenaas 1
1 Department of Physics, Norwegian University of Science and Technology, 7491 Trondheim,
Norway
2 SINTEF Materials and Chemistry, 7465 Trondheim, Norway
Abstract
A KrF laser was used to ablate a polycrystalline Si target for deposition of Si on MgO and
GaAs substrates at room temperature. The deposition was performed in 10 -8 mbar, with two
types of laser beams: a homogeneous beam being imaged onto the target, and a nonhomogeneous
which is nearly focused. Submicron to micron sized droplets was detected on
the deposited films. Raman spectroscopy showed that the micron sized droplets are crystalline
while the film is amorphous. The generation of the large droplets in the case of a nonhomogeneous
beam is most likely related to the cone structures formed on the ablated target.
We also compared cone formation on a polycrystalline Si target and a single crystalline Si
wafer, using multiple laser pulses onto a single spot.
PACS number: 81.15.Fg , 52.38.Mf, 68.55.ag , 68.55.-a
*Corresponding author, e-mail: seong.yap@ntnu.no; Fax: +4773597710
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Photovoltaic research in Southern Norway
Anne Gerd Imenes a,b (anne.g.imenes@uia.no), Deepak Verma a (deepak.verma@uia.no),
Georgi Yordanov a (georgi.yordanov@uia.no), Chee Lim Nge a (che.l.nge@uia.no), Rune
Strandberg b (rst@teknova.no), Thomas Meyer b (tme@teknova.no), Tor Oskar Sætre a
(tor.satre@uia.no), Ole-Morten Midtgård a (ole-morten.midtgard@uia.no),
a University of Agder, Groosevn. 36, 4876 Grimstad
b Teknova AS, Gimlemoen 19, 4630 Kristiansand
This paper will give an overview of the various R&D activities supported by the fastgrowing
photovoltaic groups at the University of Agder and the research institute
Teknova, located in Southern Norway. The research team now constitute a total of 10
people with activities linked to different generations of photovoltaic technology. The
overall objective is to build up competency, knowledge and technological solutions of
high international standard and competitiveness, and to collaborate with national players
in order to strengthen Norway's position as a significant contributor to the international
photovoltaic R&D community.
First generation photovoltaics refer to traditional mono- and polycrystalline silicon solar
cells. The University of Agder and Teknova are working closely with Elkem Solar, a
world-class manufacturer of solar grade silicon located in Kristiansand. Activities include
two projects funded by the Norwegian Research Council. The first, 'End use of
photovoltaic technology in Norway', is focussing on module performance and inverter
technology for grid-connected systems. The second, 'Field- and accelerated lab testing
qualifying PV modules made of solar grade silicon from a low cost energy efficient
metallurgical route', is starting up in 2010 and will look into degradation issues for silicon
solar cells exposed to long-term outdoor conditions.
Second generation photovoltaics generally refer to methods of reducing the cost of
photovoltaic technology, such as using thin film solar cells, alternative materials, or
improved light collection methods. Researchers at Teknova have investigated the use of
fluorescent solar collectors and optical filtering in order to improve system economy.
Another important aspect is the use of thinner glass with optimised material properties
and surface treatment, whether it be thin film or traditional solar cells.
Third generation photovoltaics refer to devices of improved efficiency, more specifically,
devices that can exceed the Shockley-Queisser detailed balance limit. Teknova will, in
collaboration with the University of Agder, continue the investigation of intermediate
band solar cells, which have a higher theoretical efficiency than the traditional singlebandgap
cells but so far have not been successful in laboratory.
Organic photovoltaics is categorized as an emerging technology with the potential of
becoming the cheapest alternative for photovoltaics in future. The University of Agder
has brought in international competency in this area and will work on optimized
compounds for improved light harvesting, charge collection and conversion efficiency of
such devices. Experimental facilities are in the planning and commissioning phase.
Further details on the various project activities and plans ahead will be given in the paper.
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Submitted for publication in Proceedings of Renewable Energy Research Conference,
Trondheim, Norway, 7 - 8 June, 2010.
How to Maximize Solar Efficiency during
Snow Downfall on Solar Cell Roofs ?
Bjørn Petter Jelle ab* , Knut Noreng a , Tao Gao c and Arild Gustavsen c
a Department of Materials and Structures,
SINTEF Building and Infrastructure, Trondheim, Norway.
b Department of Civil and Transport Engineering,
Norwegian University of Science and Technology (NTNU), Trondheim, Norway.
c Department of Architectural Design, History and Technology,
Norwegian University of Science and Technology (NTNU), Trondheim, Norway.
*Corresponding author: E-mail: bjorn.petter.jelle@sintef.no, Phone: 47 73 59 33 77
Introduction
Traditionally, the main purpose of roofs has been to protect the users of the buildings from the
exterior climate, including snow. However, solar cell roofs should ideally have no snow covering
the cells, in order to maximize the solar cell energy production.
Two Snow Philosophies
The two contradictory snow philosophies are:
Philosophy 1 – Keep the snow on the roofs
– Normal roof solution in order to avoid hazardous snow downfall from the roof, snow/ice roof damages and
accumulation of snow in front of entrances, pathways, etc.
Philosophy 2 – Remove the snow from the roofs
– Increased solar cell efficiency when not covered by snow.
Some possible solutions for snow philosophy 2 are:
Philosophy 2 – Remove the snow from the roofs – Possible solutions
– New advanced material/surface technology, e.g.
• ”Zero” friction for snow and ice – Immediately removal of falling snow.
• Self-heating materials (e.g. from ambient infrared radiation or solar radiation)
• Self-cleaning surface.
– New roof design
– Others?
Climate Conditions and Possible Paths towards a Snow-Free Solution
Under certain climatic conditions snow and ice may firmly adhere to solar cell and various glass
surfaces even at large inclination angles (Fig.1, left and middle). Various paths, with idea
generation (Fig.1, right) may be followed in the search for a solution with no increased energy
consumption, e.g. architectural, low friction non-sticky (nano modified) surface immediate
removal, self-cleaning surface, self-heating material or force field solutions.
Snow Crystals
Infrared Radiation
IR
Solar Radiation
UV-VIS-NIR
Solar Cells with...
Low Friction Non-Sticky Self-Cleaning
Self-Heating Material Surface ?
Force Field
Repulsive
Surface ?
What Happens on a
Molecular/Atomic Level ?
Fig.1. Solar cell panel covered by snow at an angle of 70º (left). A snow/ice slab firmly sticking to the glass surface of an insulated
window pane even at an inclination angle of 90º during a laboratory experiment (middle). Illustration of a low friction
non-sticky self-cleaning self-heating material surface solution – and with a force field – in order to generate ideas (right).
Conclusions
Various ideas and possible steps towards a solution of the problem with snow downfall on
photovoltaic solar cell roofs have been discussed, which may then in turn set in motion creative
thinking and problem solving paths within the scientific community with new follow-up articles.
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Wet Chemical Synthesis of Silicon Quantum Dots for
Photovoltaic Applications
Mustafa H. Balci (mustafa.balci@material.ntnu.no), Malin Sletnes
(malin.sletnes@material.ntnu.no), Urd S. Olden (urdsathe@stud.ntnu.no), Per Martin
Rørvik (permarr@material.ntnu.no) Tor Grande (grande@material.ntnu.no) Mari-Ann
Einarsrud (mari-ann.einarsrud@material.ntnu.no)
Norwegian University of Science and Technology, Department of Materials Science and Engineering.
Nano-material designing is a very promising approach to increase the efficiency of solar cells by utilising
more of the solar spectrum due to the quantum confinement effect. Several applications of Si quantum
dots (QDs) in photovoltaics have been suggested, such as an all silicon tandem cell, hot carrier cells, and a
photoluminescent down-conversion layer.
Wet chemical synthesis of Si QDs is attractive because it offers the possibility of high outputs with
simultaneous control of particle size and surface chemistry without the need for large investments in hightech
equipment. Several methods have been developed, but still little is known about the mechanisms
governing the particle size and size distribution. We are investigating different wet chemical routes to Si
QDs, and systematically varying the synthesis parameters to gain understanding about these mechanisms.
Our focus is also on creating environmentally friendly synthesis routes. Photoluminescence spectroscopy,
FT-IR, STEM and HR-TEM are used for the characterization of the Si QDs. Si QDs have been prepared
both by homogeneous and heterogeneous wet chemical synthesis routes. Particles with sizes ranging from
50 to 2 nm with different size distributions and particle morphologies have been synthesised. Surface
functionalization has been obtained by capping with n-octanol, n-butanol, n-hexanol and short alkyl chains,
as well as etching with hydrogen peroxide in order to make a silica shell of controlled thickness. For the
etched quantum dots vible blue luminescence has been observed with a UV lamp at 366 nm exitation
wavelength. The synthesis parameters will be further optimised for the production of Si QDs for solar cell
applications, and the concept of a down-conversion thin film layer will be tested.
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Si
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Simulation of phosphorus removal from silicon by induction
vacuum refining
Song-sheng Zheng a, b (songshen@material.ntnu.no)
T. Abel Engh b (thorvald.engh.nerja@gmail.com)
Merete Tangstad b (merete.tangstad@material.ntnu.no)
Xue-tao Luo a (xuetao@xmu.edu.cn)
a XMU Department of Materials Science and Engineering, Xiamen 361005, P R China
b NTNU Department of material technology, Trondheim 7034, Norway
[ABSTRACT]: Phosphorus can be expected to evaporate preferentially from silicon melt
by induction vacuum refining (IVR). In the present study, on the assumption of
phosphorus evaporating from silicon melt as gas species P and P2, a numerical model has
been developed for phosphorus removal by IVR, and the mass transfer coefficients for
three possible rate limiting steps are developed. According to the IVR model, the factors
affecting phosphorus removal in decreasing order are temperature, chamber pressure,
geometry of silicon melt, holding time and original phosphorus concentration. A high
phosphorus removal will be accompanied with a high silicon loss. Calculated phosphorus
removal using the IVR model shows good agreement with the present experimental data.
Keywords: induction vacuum refining, mass transfer coefficient, temperature, pressure,
phosphorus concentration, holding time
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ABSTRACTS
Hydropower
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Scenarios for hydro power development in Norway to cover peaking
and load balancing needs in a European system with increasing use of
non-regulated renewables
Maria D.Catrinu, Eivind Solvang and Atle Harby
SINTEF Energy Research, Trondheim, Norway
The future energy system in the North of Europe will probably see significant
development of non-regulated renewables like wind power (onshore/offshore) and
unregulated hydropower. This situation will increase the need for regulated (balancing)
hydropower both for peaking and as backup during periods of low wind or low
unregulated inflow.
The present hydropower system in Norway (and in the Nordic and European hydropower
system) has mainly been developed for supply of base load and energy. In principle, the
system has substantial capacity for producing more peaking power as backup during
periods of low wind or low unregulated inflow. Moreover, there is a large potential both
for upgrading and refurbishment of the existing system as well as for developing new
hydropower with reservoirs and/or pumping capacity.
Hydropower peaking and hence rapid variations in flow and reservoir levels, will bring
new challenges to the operation of the existing hydropower system, and may have
adverse effects on machinery, hydraulic structures, dams and tunnels, and also in rivers
and reservoirs.
If new hydropower capacities will be developed in Norway to cover the needs for
peaking and regulated power in the Nordic region / Europe, then significant transmission
infrastructure will have to be developed. Such a grid infrastructure might not be
motivated by the use of renewables alone. The future electricity and CO2 (green
certificates) markets and market arrangements will have to be designed to enable these
developments, supported by binding political commitments and international agreements
to stabilize the growing Pan-European grid, to provide higher security of supply, and to
foster competition.
This paper discusses scenarios for hydropower development in Norway on short and long
term (20-40 years) as a response to the future energy challenges in Europe and Norway.
We will define a set of elements that will be used in the construction of scenarios:
opportunities, barriers and possible evolutions in time. Technical, economical, social and
political premises for a ‘hydropeaking’ regime/market will be discussed.
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The paper presents ongoing work within the HydroPeak project at SINTEF and NTNU in
Trondheim, Norway. The HydroPeak project is a part of CEDREN – the Centre for
Environmental Design of Renewable Energy
(http://www.sintef.no/Projectweb/CEDREN/). The objective of the centre is to develop
and disseminate effective design solutions for renewable energy production that take
adequate account of environmental and societal issues, both locally and globally.
Authors
Maria D.Catrinu is a research scientist at SINTEF Energy Research, Department of Energy
Systems, Trondheim, Norway. She received her MSc. degree in electrical power engineering from
Politehnica University of Bucharest, Romania, in 2000, and her Ph.D. within the field multicriteria
decision aid for energy systems planning from the Norwegian University of Science and
Technology (NTNU), Trondheim, Norway, in 2006. She is working with power and energy
systems planning, risk-based asset management and decision support systems.
Eivind Solvang is a senior research scientist at SINTEF Energy Research, Department of Energy
System, Trondheim, Norway. He received his M.Sc. degree in electrical engineering from the
Norwegian Institute of Technology, Trondheim, in 1976. He is mainly working with technical and
economical optimization of maintenance and replacement, lifetime modelling and asset
management.
Atle Harby is a senior research scientist at SINTEF Energy Research, Department of Energy
System, Trondheim, Norway. He received his M.Sc. degree in Civil engineering from the
Norwegian Institute of Technology, Trondheim, in 1988. He has varied professional practice in
environmental engineering with emphasis on environmental impacts of river regulations and
water resources problems. Main interest in aquatic ecosystem modelling. Experience with stream
habitat modelling and hydrological analyses, including river modelling systems, precipitationrunoff
models, flood risk analysis.
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NORWEGIAN HYDROPOWER A VALUABLE PEAK POWER
SOURCE.
Hermod Brekke, Professor Emeritus NTNU .
SUMMARY OF CONTENT:
The paper gives a historical technical review of the development and installation of
approximately 20 000 MW of hydraulic turbines in Norway after World War II. The
non polluting production of electricity was consumed for lightening and heating for civil
consume and the growing electric furnace industry in Norway in addition to export in
rainy years.
The paper is mainly based on the authors experience in the design of large turbines, and
control systems for operation of Francis Turbines and Reversible Pump Turbines for
high and medium heads and Pelton turbines for high heads.
During the last 15 years the development of small hydro power plants has also given an
increasing contribution to the power production. A brief discussion will be given on the
choice of equipment for small hydro production with a very small winter production and
overload during the summer. The possibility of operation of a small hydropower plants
connected to an isolated grid will also briefly be presented.
In addition to the general design of turbines and control systems for large hydro plants, a
detailed description will be given of the stability analysis for the governing system which
was developed for the large high head plants with long high pressure tunnels systems.
A discussion will be included on the introduction of the air cushioned surge chambers
for fast stable operation of power plants with long tunnels, connected to isolated grids.
Also the principle of stabilizing unstable turbine governing system by means of pressure
feed back systems, will be presented and discussed. A description of such system
developed in 1992, will be given proving that stability could be obtained in a system with
long conduits connected to the turbines. However, the “governing speed” needed for
isolated operation could not be fulfilled without a fast by pass pressure relieve system
for Francis turbines, which was not installed in the case for the analysis.
Finally a discussion will be given on a possible increase of the Norwegian hydropower
peak power production to meet the growing the European demand for peak power
caused by the growing non stationary production from wind mills and ocean energy
from waves and sea current. Also building of reversible pump turbine power plants will
be discussed even if approximately 10% power will be consumed by loss in the pumping
phase compared to direct use of the water from reservoirs.
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Hydro investment analysis under new market conditions
Gerard Doorman, NTNU
A future energy system with stronger coupling to Europe and with an increased share of
non-regulated renewables will lead to increasing variability of the demand faced by the
hydro system. In a market based system these variations will be reflected by larger daily
price variations, both in the Elspot day ahead market, the Elbas intraday market and in
the balancing market. With its unique regulation capabilities, hydro power will be very
well positioned to handle these variations. However, existing model concepts for long
term hydro scheduling were not developed for this framework, and do not take the new
market conditions into account to a sufficient degree. Therefore hydro scheduling tools
used for upgrading and investment analysis as well as analysing consequences of new
environmental demands need adaptation to a finer temporal resolution, and to perform
optimisation under varying constraints and uncertain input data for inflow and electricity
prices. Focus is on investment analysis for a river system or power producer.
Existing models can be grouped in the long-term (scheduling models with a time horizon
up to 5 years) EOPS (Vansimtap), EOPS-ST (SimtapEffekt) and ProdRisk, and the shortterm
scheduling models with a typical time horizon up to a few weeks, but focus on 1-2
days (SHOP and ID-SIM). A perfect tool in the present context would combine the
properties of the long term stochastic optimisation models with the modelling details of
SHOP and/or ID-SIM. However, this is probably not possible and simplifications will be
necessary.
Some important deficiencies in the present long term models are:
Insufficiently realistic plant models in the relevant optimization models
Time delays are not handled
Handing of flexible / state dependent constraints
Handling of ramping constraints
Modelling of the cost of frequent regulations (wear and tear)
Reserve markets
As a result of these deficiencies the investment analysis does not adequately assess the
value of new capacity.
Several approaches will be considered and evaluated, among these:
Development of EOPS-ST. This model combines long term stochastic
optimization with a more detailed short term model that uses linear programming.
Development of ProdRisk, which is based on Stochastic Dual Dynamic
Programming (SDDP) that allows for more detailed modelling than the traditional
SDP approach.
A new method using simulator based hydro scheduling models, where first stage
decisions are based on deterministic equivalents. A model of this type has been
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tested for the hydro thermal market problem with good results, but so far without
the necessary level of detail.
As a first step these approaches will be compared with respect to their potential to solve
the actual tasks. The next step will be to implement necessary extensions in the most
promising model. In the final phase, the enhanced model will be used for relevant
analyses like capacity increases in existing plants, pumped storage, the effect of
constraints etc.
The presentation will include relevant examples of the impact of higher daily price
variations on the operation of the Sira Kvina system.
Renewable Energy Research Conference 2010 64

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Impact of reservoir sedimentation versus storage of new renewable
energy
Tom Jacobsen
SEDICON AS
Professor Brochs gate 2
7030 Trondheim
Norway
toja@sedicon.no
www.sedicon.no
Reservoirs will play an increasingly important role in storing energy, not least from new
renewable sources such as wind, wave and solar. Energy from these courses is unreliable
and / or unevenly distributed in time. At the same time, substantial reservoir volume is
lost to sedimentation, often in the very regions that has high population density and
limited water end energy supply.
The paper presents a general overview of reservoir sediment problems on a global scale
and the consequences it has especially versus the increasing need for storage of new
renewable energy. Relevant cases of reservoir sedimentation in countries such as the
Philippines, Nepal, Peru and Iran, and how these problems have been dealt with up to
now.
The paper finishes with a presentation of different reservoir design philosophies,
reservoir operation strategies and technologies that can be used to reduce the long term
impact of reservoir sedimentation.
The Author
T. Jacobsen graduated in Hydraulic engineering from NTNU, the University of Science and Technology in
Trondheim, Norway in 1990. He then worked for a construction company Skanska for two years. In 1997
he defended his doctoral thesis “Sediment Problems in reservoirs – control of sediment deposits”. From
1999 and onwards has been working for the Norwegian company SediCon as consultant, developer of
sediment handling technologies and with implementation of sediment removal projects both offshore well
as for hydropower projects.
Renewable Energy Research Conference 2010 65

The Centre for Renewable Energy
NTNU - SINTEF - IFE
NORHARD - game changing drilling contractor.
Askhjell Tonstad, NorHard AS
Company presentation
Drilling contractor for onshore tunnels in hard rock
Game changing and patented technology
Own production of critical components
Full service drilling contractor
Market
Priority: Small Hydro plants
Next step: Transmission Lines, Infrastructures and Geothermal wells
Technology
Drilling from bottom
Fully electric operated
Direction and position control
Online communication
Process control
No polluting waste
Planned diameter range: 380 mm – 2000 mm
Long distance drilling. Up to several km.
Renewable Energy Research Conference 2010 66

The Centre for Renewable Energy
NTNU - SINTEF - IFE
Abrasion resistant turbines
By
Ole Gunnar Dahlhaug, The Norwegian University of Science and Technology
Abstract submitted to
Renewable Energy Research Conference
Renewable Energy Beyond 2020
Trondheim 7 th –8 th June 2010
There are many hydro power plants that are affected by large amounts of sediments
during the rainy/ monsoon season. Himalaya in Asia and Andes in South America are
examples of large regions where there are hydro turbines which experience heavy
sediment erosion every year. Turbine manufacturers have been developing new materials
and coatings that can be used in turbines. The most successful solution seems to be
wolfram based coatings. In Francis turbines, the coating has been applied to the cover,
guide vanes and some parts of the runner. The coating of the whole Francis runner has
been difficult because there is simply not room for the equipment to apply the coating to
the surface.
DynaVec, which is a spin out company from NTNU, have developed a new production
method that allows them to apply the coating to the whole surface of the runner vanes.
This has been applied to a runner at Cahua Power Plant in Peru. The Power Plant has two
Francis turbines where each has a power output of 23 MW. The head is 215 meter and the
sediment erosion in the turbines is severe. The turbines are operated at maximum 5000
ppm sediment concentration and the sediment the passes the turbine has about 30%
quartz and 30% feldspar content. This means that the turbine has a maximum sediment
load of 50 kg/s and 60% of this is minerals that are harder than the base material of the
turbine.
The first runner and guide vanes were installed in February 2009 and the second one was
installed in February 2010. DynaVec has carried out efficiency measurements and visual
inspection of the turbine through the rainy season in the spring 2009. The results from
these measurements and visual inspections will be presented at the conference.
Renewable Energy Research Conference 2010 67

The Centre for Renewable Energy
NTNU - SINTEF - IFE
Reversible Pumped Hydro – benefits and challenges
Torbjørn K. Nielsen (torbjorn.nielsen@ntnu.no)
Eve C. Walseth (eve.c.walseth@ntnu.no)
a Norwegian University of Science and Technology, Trondheim, Norway
The Norwegian hydro power system is dominated with high head turbines, Pelton and
Francis with high capacity in the reservoirs. Originally they were built for secure energy
supply. In the system there are also reversible pump turbine (RPT) plants where in times
with spare energy, made it possible to pump water from the lower reservoir to the higher.
Again the idea was to secure energy supply, which meant pumping in early autumn to fill
the reservoirs for winter.
In the recent years, a more active use of the RPT plants has been actualized. The free
market made price difference between night and day interesting, hence a more frequent
pumping was desirable. In the coming years, new-renewable energy sources will utterly
enhance a more active use of the RPT plants.
More active use of the RPT plants means more frequent starts and stops, both in pumping
and in turbine mode. There are a lot of challenges in adopting a new strategy for
operating the machinery. More effective start equipment is required. The machinery will
be exposed to more frequent dynamic loads; the turbines will be run at part- and full load.
The existing RPT plants are connected to huge reservoirs. That means the RPTs are not
only for short sighted power regulations, as many RPT-plants in Europe, but are also
capable for a substantial energy production.
In Norway, the nature is very suitable for RPT plants, both in connection with existing
power plants, were reservoirs and conduits are already established, and standing alone
with a minimum of energy production.
RPTs are, as a design, a compromise between effective generating and stable as well as
effective pumping. Stable pumping often results in very steep flow-speed characteristics
when operating as a turbine. When dealing with hydraulic transients these characteristics
cause a higher change in flow and torque leading to instability during start-up and
possible off-design operation point. The instability slows down the synchronization
process during start-up in turbine mode, which is undesirable when the goal is to increase
the flexibility.
The introduction of the free market and increased focus on non-regulative renewable
energy sources has led to a need for new operating patterns in the Norwegian hydro
power system. Reversible pump turbines can increase both the flexibility and stabilize the
grid with increased production from non-regulative renewable energy sources.
Renewable Energy Research Conference 2010 68

The Centre for Renewable Energy
NTNU - SINTEF - IFE
A tool to assess morphological changes in a delta due to hydropower
regulation
Peggy Zinke a (peggy.zinke@ntnu.no)
Nils Ruether a (nils.ruther@ntnu.no)
Nils Reider B. Olsen a (nils.r.olsen@ntnu.no)
a Norwegian University of Science and Technology, Trondheim, Norway
The paper introduces a three dimensional numerical model being able to calculate flow
and morphological changes in a delta of a confluence of three rivers with downstream
reservoir. The delta is the largest fresh water delta in northern Europe. The sediments of
the three incoming rivers Glomma, Leira and Nitelva have formed a group of islands with
lagoon-like structures covering an area of about 9 km2. In recent years, successive
regulation phases have gradually reduced the amplitude of seasonal variations in water
stage from the natural range of 8 m and resulted in an extended period of high and more
constant water level. Local sediment redistribution within the delta has decreased over
the years, reducing the downstream extent of the sedimentation zone. To assess the
environmental impacts of the hydropower regulations, there is a need to evaluate the
impact of changes in the operational directives for the power station on the processes of
delta erosion and sedimentation. The paper presented preliminary results of the
simulation of flow in the delta including a
detailed analysis of the discharges in each
of the side arms and a comparison to
measured velocity data. I addition it
presents preliminary results of the
simulation of bed changes over time in a
natural river bed covered with dunes. The
initial geometry was taken from high
resolution bathymetric data obtained by an
interferometric multibeam, and covered a
length of 120 meters in the 50 meters wide
river. The data set indicated a predominant
structure of three dimensional bed forms.
Measurements were taken with 24 hour
intervals, showing the dune movement.
The numerical model computed
reasonable velocity field and bed shear
stress profile over the dunes. The
computation of the dune movements also
showed similarities with the field
measurements.
Figure 1 – This is an example figure
Renewable Energy Research Conference 2010 69

The Centre for Renewable Energy
NTNU - SINTEF - IFE
Greenhouse Gas Emissions of Hydro Power – state of the art
Hanne Lerche Raadal a (hlr@ostfoldforskning.no),
Ingunn Saur Modahl a (ism@ostfoldforskning.no)
a Ostfold Research, Gamle Beddingvei 2B, N-1671 Kråkerøy, Norway
Ostfold Research is currently running the project Energy Trade and Environment 2020.
The project started in February 2009 and will last until August 2012. The objective of the
project is to contribute to a significant reduction in greenhouse gas emission from energy
generation and consumption, both nationally and internationally. This is expected to
happen as a result of:
making it more profitable to invest in new, renewable energy both in Norway as
well as internationally by using environmental information in the trading system
increased competitiveness and value adding in the Norwegian energy companies
related to sales of sustainable energy resources
creation of new knowledge within the fields of R&D as a platform for researchbased
teaching through the development of a research centre for sustainable
energy trade in the counties of Østfold and Akershus.
A PhD within this field will also be carried out as a part of the project.
One part of the project is to develop consistent models for documentation of the
environmental impact from the generation and use of electricity. The Life Cycle
Assessment (LCA) and Environmental Product Declaration (EPD) methodology will be
used as a basis for this environmental documentation. The project work has started with a
review and comparison of recent greenhouse gas (GHG) emission LCAs (Life Cycle
Assessments) of hydro power.
The results from this work will present the state of the art for the environmental impact
category Global Warming Potential (GWP) for different hydro power plants (reservoir
and run-of-river). The results will be presented as total greenhouse gas emissions per
kWh generated, divided into the different life cycle stages for the power plants
(infrastructure, operation etc) to present which life cycle stages are the most important to
the overall greenhouse gas emissions. The state of the art work for hydropower will be
finished during spring 2009, just in time for presentation at the The Renewable Energy
Research Conference.
Renewable Energy Research Conference 2010 70

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NTNU - SINTEF - IFE
Assessing the impact of hydropower and climate change on the fish
fauna in Alpine rivers
Andreas Melcher, Günther Unfer and Stefan Schmutz
IHG - Institute of Hydrobiology and Aquatic Ecosystem Management
WAU - Department of Water, Atmosphere and Environmen,
BOKU - University of Natural Resources and Applied Life Science,Vienna, Austria
Contact: email: andreas.melcher@boku.ac.at Tel.: +43-1-47654-5223, Fax: +43-1-47654-5217
Water temperature is amongst other factors a driver of fish community composition in
rivers. Climate change and human pressures caused by hydropower can change the
temperature regime and cause alterations of the fish fauna.
In this paper we (1) use observed water temperature data from 1976 to 2005 to develop
multiple linear regression models and to predict water temperature based on other abiotic
parameters. Three variables, altitude, mean monthly flow rate, and distance from the
source are able to describe up to 80% of the variance of mean monthly water
temperatures during summer. Analyses of water temperature timelines showed a warming
trend over the last 30 years.
Furthermore (2), we use ecological models driven by monthly water temperature and
human pressures to evaluate their impact on fish communities. We found significant
correlations between human impacts and fish response.
For water bodies dominated by European grayling (Thymallus thymallus), which are
mainly influenced by hydropower, the typical mean water temperature for August ranges
from 12 to 14°C. Salmonid species are cold water species with limited tolerance against
high water temperatures. Several case studies show lowered densities, biomass and a shift
of the fish species composition due to hydropeaking, impoundment and the change of
water temperature.
Derived conclusions concerning habitat quality and in particular water temperature will
provide important information for the planning of future restoration and mitigation
measures in hydromorphologically impacted rivers under the respect of climate change.
Renewable Energy Research Conference 2010 71

The Centre for Renewable Energy
NTNU - SINTEF - IFE
Environmental redesign of hydropower. Potential and examples.
Atle Harby a (atle.harby@sintef.no)
Torbjørn Forseth b (torbjorn.forseth@nina.no)
a SINTEF Energy Research, 7465 Trondheim, Norway
b Norwegian Institute for Nature Research, 7485 Trondheim, Norway
Most of the Norwegian hydropower system was designed more than 30 years ago when
environmental concern was lower and the focus was on energy supply security. In the
recent years, environmental impacts have gained more focus and we have obtained more
knowledge about the function of aquatic ecosystems and their relationship to changes
caused by river regulation. The energy system has been operated as a free marked for
many years and the future scenarios with integration of an increased amount of
intermittent energy sources will lead to changes in the operation of regulated rivers. On
top of this, climate change is another factor that has both direct and indirect impacts on
the operation of hydropower systems.
The combination of more focus on environmental impacts, changes in operation
strategies and climate change may create possibilities to increase both the power
production income and the environmental conditions in regulated rivers. If this is
combined with upgrading and refurbishment, the potential of creating “win-win” for both
power production and the environmental conditions is even higher. The principle for winwin
situations will be drawn and some examples of this will be shown.
In order to mitigate the negative impacts of hydropower development in the River Surna
in Mid-Norway, several options are investigated to optimize the mitigation. In the section
with reduced flow, a small hydropower plant may release diverted water back into the
river. The amount and timing of flow released through the small hydropower plant are
studied to increase fish production. Fish growth in summer is affected by cold water
release from the reservoir, and several alternative intake solutions are investigated in
order to increase fish growth. Due to hydro operations, potential stranding of fish are
investigated. Results will also include the cost and gains of each alternative.
Scenarios of climate change and possible changes in air temperature, water temperature
and discharge in the regulated river Orkla in Norway was studied in order to predict
possible impacts on Atlantic salmon (salmo salar) populations. Results indicates
increased hydropower production, less spill of water, higher discharge in winter, reduced
periods with surface ice cover, higher water temperature in spring and early summer,
increased energy consumption in salmon and then higher mortality in winter, increased
growth of salmon during spring and better conditions for fish migration in regulated
rivers. The overall results indicates increased production of energy and salmon.
Renewable Energy Research Conference 2010 72

The Centre for Renewable Energy
NTNU - SINTEF - IFE
Assessment of small versus large hydro-power developments –
A Norwegian case study
Tor Haakon Bakken a (tor.haakon.bakken@sintef.no),
Atle Harby b (atle.harby@sintef.no)
a SINTEF Energy Research
b SINTEF Energy Research
The era of new, large hydro-power development projects seems to be over in Norway.
Partly as a response to this, a large number of applications for the development of smallscale
hydro power projects up to 10 MW overflow the Water Resources and Energy
Directorate, resulting in an extensive development of small tributaries and water courses
in Norway. This study has developed a framework for the assessment and comparison of
several small versus many large hydro-power projects based on a multi-criteria analysis
(MCA) approach, and further tested this approach on planned or developed projects in the
Helgeland region, Norway.
Multi-criteria analysis is a decision-support tool aimed at providing a systematic
approach for the comparison of various alternatives with often non-commensurable and
conflicting attributes. At the same time, the technique enables complex problems and
various alternatives to be assessed in a transparent and simple way. The MCA-software
was in our case equipped with 2 overall criteria (objectives) with a number of subcriteria;
Production with sub-criteria like volume of energy production, installed effect,
storage capacity and economical profit
Environmental impacts with sub-criteria like fishing interests, biodiversity,
protection of unexploited nature
The data used in the case study is based on the planned development of Vefsna (large
project) with the energy/effect production estimated and the environmental impacts
identified as part of the feasibility studies (the project never reached the authorities’
licensing system with a formal EIA). The small-scale hydro-power projects used for
comparison are based on realized projects in the Helgeland region and a number of
proposed projects, upscaled to the size of the proposed Vefsna-development.
The results from the study indicate that a large number of small-scale hydro-power
projects need to be implemented in order to balance the volume of produced
electricity/effect from one large project. The possible accumulated environmental impacts
from a portfolio of small-scale projects might go far beyond the estimated impacts from
one large projects developed.
Renewable Energy Research Conference 2010 73

The Centre for Renewable Energy
NTNU - SINTEF - IFE
Assessment of the river ice conditions in Lundesokna, a small hydropeaked
river in central Norway
Håkon Sundt a (hakon.sundt@sintef.no),
Tor Haakon Bakken a (tor.haakon.bakken@sintef.no)
a SINTEF Energy
Ice formation and break-up is expected to play a major role and possibly being a critical
factor in river ecology in steep rivers (Prowse and Culp 1 , 2003 and Stickler et al. 2 , 2009).
As the ice formation also might change the conveyance capacity of the river, it can also
have major technical implications as it can increase the risk of flooding. Lundesokna is a
small and river located approximately 30km south of Trondheim in central Norway being
exposed to frequent and rapid changing flow (‘hydro-peaking’). As part of the
EnviPEAK-project 3 the ice conditions were studied in Lundesokna during the severe
winter season of 2009/2010.
In Lundesokna, automatic registrations of water level and water temperature are being
conducted at three specific locations downstream the river outlet of Sokna power plant.
The Lundesokna river catchment is regulated by several power plants and reservoirs,
which influences the flow pattern in different reaches.
Preliminary analysis of the monitoring data indicate that winter rating curves during ice
formation show deviation from summer rating curves at specific locations. Rating curves
deviate longitudinal along the river reach, possibly due to dissimilar build-up of ice at the
different locations investigated, as shown in Figure 1 for year 2010, indicating deviating
water level variations on the 20 th of February.
Figure 1 – Water level registration at three locations in Lundesokna
1 Prowse, T.D. and Culp, J.M. Ice break-up: a neglected factor in river ecology. Can. J. Civ. Eng. 30: 128-
144. 2003.
2 Stickler, M. Alfrdsen, K.T., Linnansaari, T. and Fjeldstad, H-M. The influence of dynamic ice formation
on hydraulic heterogeneity in steep streams. River Research and Applications. 2009.
3 The EnviPEAK-project is a project organized within the Centre for Environmental Design of Renewable
Energy (www.cedren.no)
Renewable Energy Research Conference 2010 74

The Centre for Renewable Energy
NTNU - SINTEF - IFE
Simulation of stranding risk of juvenile fish due to hydropeaking using
the habitat model CASiMiR
Markus Noack a (markus.noack@iws.uni-stuttgart.de),
Matthias Schneider b (schneider@sjeweb.de)
Silke Wieprecht a (wieprecht@iws.uni-stuttgart.de)
a Universitaet Stuttgart, Institute of Hydraulic Engineering, Germany
b sje – Schneider & Jorde Ecological Engineering GmbH, Germany
Extreme fluctuations in daily discharge caused by hydropower plant operations, also
known as hydropeaking, are used to cover peak power demand. Hydropeaking can cause
rapid flow fluctuations in downstream rivers with drastic impacts on river ecology. One
potential impact is the stranding of fish. This article presents an approach to simulate
stranding risk of juvenile grayling qualitatively and quantitatively using a multistep
fuzzy-logical approach that is implemented in the habitat simulation tool CASiMiR.
In a first step, the basic habitat suitability is calculated using the parameters water depth,
flow velocity and substrate size. This gives information about the distribution of habitat
use over a range of different flow conditions. After simulating the basic suitability of
juvenile habitats, the influence of rapid flow reduction is incorporated in a second step by
defining a tolerable down-ramping rate for juvenile fishes. This depresses the rapid flow
reduction to a level where the juveniles are able to follow the decreasing water level. The
critical ramping rate, the information about the habitat shift combined with a required
minimum water depth allows the determination of stranding risk areas in the downstream
river reach.
The third step determines the potential stranding risk in inundated areas which have been
cut off from the main channel. River side arms and sunken areas along gravel banks are
inundated during the high flow period and become completely disconnected during the
flow reduction. Fishes in these areas have no possibility to return to the main channel,
and thus remain trapped.
As long as juvenile fish were able to follow the decreasing water level, the rapid flow
reduction and separation of wetted areas may not pose a problem. However the presence
of both stranding risks significantly increases the likelihood of mortality for juvenile
fishes which is considered in the last step of the approach.
The developed approach was applied in three study sites of the River Saane in
Switzerland. The investigated fish species were juvenile graylings and bullheads. Based
on the results of this approach critical discharge ranges in the operational mode of the
hydropower plant could be identified with regards to fish stranding. Furthermore, the
results could be used to develop several management scenarios for hydropeaking to
optimize the interests of both ecology and economy.
Renewable Energy Research Conference 2010 75

The Centre for Renewable Energy
NTNU - SINTEF - IFE
A Procedure for Assessing Climate Change Impacts on Hydropower
Hamududu B a , Jjunju E b ,Killingtveit Å c , Alfredsen K d
a,b,c,d
Norwegian University of Science and Technology(NTNU), Faculty of Engineering
Science and Technology, Department of Hydraulic and Environmental Engineering
Ever since climate change was highlighted as an important issue in water related projects,
various procedures have been used by different researchers to gain indications of likely
impact of climate change on hydropower. Though all methods give results, comparisons
of these results is not ideal and may be difficult due to large differences in methods used.
This paper is an attempt to propose an ideal procedure or process of estimating the impact
of climate change on hydropower production in a basin. The paper describes where to
begin, what future climate change projections are necessary, and where to get such data.
It also shows highlights various techniques that are available and could be applied to
climate projections in order to downscale the large scale projections from global climate
models to site or basin climate. Another technique that has been applied is the delta
approach or perturbation methods that transfer changes in meteorological variables
between the control and the scenario simulations from the regional climate model to a
database of observed meteorological data. Further it highlights various ways of
transforming basin climate variables that can be used in hydrological modeling to
produce runoff series. The paper also discusses applicability of hydrological modeling
strategies for climate predictions in relation to stationarity in models and how this will
influence climate predictions. The runoff is the input into hydropower systems and
hydropower simulations to get the desired hydropower production in the future. In all
these steps, different approaches for processing are highlighted. The paper ends with a
section on different sources of uncertainties in climate projections. Finally some
concluding remarks are given on the reliability of the results from various methodologies.
A case study on Zambezi River basin is given towards the end illustrating the differences
resulting from different methodologies.
Key words: Climate Change, Impact Assessment, Hydropower, Procedures,
Hydrological Modeling, Hydropower simulations,
Renewable Energy Research Conference 2010 76

The Centre for Renewable Energy
NTNU - SINTEF - IFE
Sustainable implementation of village level hydropower in
Eastern and Southern Africa
Wim Jonker Klunne a (wklunne@csir.co.za)
a Council for Scientific and Industrial Research (CSIR)
PO Box 395, Pretoria 0001, South Africa
Local village level small hydropower schemes can play an important role in energising
rural areas in Africa, in particular those areas far away from the national electricity grid.
The large knowledge base on technical aspects of small scale hydropower indicates a
proper understanding of the technology involved. However, at the same time the number
of hydro projects implemented does not reflect the enormous potential that exists in
Africa, suggesting that other barriers than the technology itself are still persistent.
Studies on rural electrification conclude that technology issues are only part of the reason
why energy access is still very low in certain areas. The way new (energy) technology is
introduced in rural areas and the systems set up for operation and maintenance are
equally important.
Although small hydropower projects have been implemented in several countries on the
continent, information on the current state of affairs is scattered, incomplete and
sometimes even inconsistent. To a limited extent information is available on technical
details of implemented projects; however, information on implementation models
followed and their successfulness is lacking in most cases
The paper will focus on Eastern and Southern Africa and does give an overview of past,
current and future small hydropower developments. It will look into the role of national
legislation and policies towards the promotion of renewable energy in general and small
hydropower in particular. The paper will also highlight a number of developments in
other regions of Africa that could be of importance to small hydro initiatives in the
Eastern and Southern African region.
Through the analysis of specific hydro schemes in the countries concerned the paper will
evaluate the role of institutional and management arrangements and practices adopted by
developers to ensure the smooth long-term operation of these systems.
The paper will draw conclusions towards methods that will increase the sustainability of
hydro systems, with an emphasis on institutional design and practices incorporated. In
this way the article will contribute to a better understanding of preferred implementation
methods and assist in unlocking the hydro potential of the continent to the benefit of
remote rural populations on the continent.
Renewable Energy Research Conference 2010 77

The Centre for Renewable Energy
NTNU - SINTEF - IFE
The Impacts of climate change on a Norwegian high-head hydropower
plant
Haregewoin Haile Chernet a (haregewoin.chernet@ntnu.no),
Knut Alfredsen a (knut.alfredsen@ntnu.no)
Ånund Killintveit a (anund.killingtveit@ntnu.no)
a Norwegian University of Science and Technology,NTNU
Abstract
Norway relies on hydropower for 99 percent of the electricity production and thus
Hydropower is important for Norway today and in the future energy system. The work
presented in this paper shows how a high-head hydropower system in Norway will be
affected in the future climate. The Aurland Hydropower system, operated by E-Co
Vannkraft, Norway is the test case for the study. The Aurland hydropower system has
many reservoirs and transfer systems and is considered to be one of the complex systems
in Norway, but also a typical example of a Norwegian high head system. The nMAG
Hydropower simulation model, which has been developed at the Norwegian Hydro
technical Laboratory, is used to simulate the hydropower system. Historical and future
inflow series were transposed from the neighbouring catchment Flåmselvi using scaling
based on area and specific runoff, as there is no discharge station in Aurland catchment
with long unregulated inflow series to set up the model and to be used for developing
future climate scenarios.
To generate the future inflow series for the analysis, the HBV hydrological model is
calibrated for the Flåmselvi catchment. The model is then used to generate future inflow
series of using the Hadley GCM (HADAm3) and A2, B2 climate scenarios. The
operation of the hydropower system is then simulated for the period 2071 -2100 to see
how future power production is affected by the change in the inflow conditions. The
HBV model is also used to see how snow accumulation will be affected in the future as
snowmelt is important for Norwegian reservoir and hydropower systems.
The Hydrologic scenarios under climate change imply an average increase in runoff for
the system. Snow accumulation will decrease with sooner snowmelt and more winter
precipitation as rain. The hydropower simulation results show that associated with the
increase in runoff there is an increase in energy generation with 10-20% under the current
reservoir operation strategies.
Keywords: Hydropower, Norway, high-head, climate change, simulation
Renewable Energy Research Conference 2010 78

The Centre for Renewable Energy
NTNU - SINTEF - IFE
POSTER PRESENTATIONS
Hydropower
Renewable Energy Research Conference 2010 79

The Centre for Renewable Energy
NTNU - SINTEF - IFE
Minimum discharge and landscape
Priska Helene Hiller, Sweco Norge AS
priska.hiller@sweco.no
The aim of the project is to combine hydrology and evaluations concerning the landscape.
In relation to hydropower, there are often discussions about how much water a power
station has to release without affecting the perception of the river in a negative way.
Systematically taken pictures of different rivers at different discharges will be presented
and compared. Existing data from several different hydropower projects will be
presented. Main focus is paid to the appearance of the rivers at low discharges.
This is an ongoing project and we are going to present the project as well as preliminary
results in terms of picture series. The project is a research project within NVEs FoU
program “miljøbasert vannføring” and will be finished in 2011.
Renewable Energy Research Conference 2010 80

The Centre for Renewable Energy
NTNU - SINTEF - IFE
THE FLUSHING PROCESS AS A POSSIBILITY
TO ADVANCE THE SEDIMENT REMOVAL
IN HYDROPOWER RESERVOIRS
Stefan Hauna (Stefan.Haun@ntnu.no)
a Department of Hydraulic and Environmental Engineering
The Norwegian University of Science and Technology; S. P. Andersens vei 5,
N-7491 Trondheim
Sediments filling reservoirs is a common problem in the world today. It is estimated that 1 - 2
% of the capacity of the hydropower reservoirs in the world is lost annually due to
sedimentation. One of the most used techniques for reducing sedimentation problems in
reservoirs is by flushing. During a flood the water level is drawn down and the increased
velocities cause erosion and transport of the sediment. However, during flushing some water
in the reservoir will be lost, causing big economical implications for the reservoir owner. The
success of the method depends also on several parameters, like water discharge, sediment
properties, grain size distribution and reservoir geometry.
The successful application of flushing will be shown on the basis of several cases, with
different reservoir capacity and rating. Like the Cachi reservoir (size 51 Mio. m3) and the
Angostura reservoir (11 Mio. m3) in Costa Rica with 285,8 MW total output. Also the
successful flushing on smaller hydropower plants, like the Kali Gandaki reservoir in Nepal
(reservoir size 0,4 Mio. m3 and 15 MW capacity) and the Bodendorf reservoir in Austria
(reservoir size 0,9 Mio. m3 and 7 MW capacity) have been considered in this paper.
A fast and reliable method to predict the flushing process is required to get better estimations
of cost and procedure benefits. The current paper gives a short introduction to the research of
Computational Fluid Dynamics (CFD) as a modern method to predict reservoir flushing
processes. Through the application of new grid types and new algorithms numerical
modelling of sediment erosion can be an alternative to plan and optimize the flushing process
for complex reservoir shapes.
Renewable Energy Research Conference 2010 81

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RESERVOIR BATHYMETRIC MAPPING FOR OPTIMUM OPERATION OF
HYDROPOWER PLANTS
Kiflom Belete
Norwegian University of Science and Technology (NTNU)
S.P. Andersen Svei 5
N 7491,
Trondheim
Norway.
Email: kiflom.belete@ntnu.no
Water reservoirs and natural lakes are built in a river system to allow water energy to be stored
during high inflow flood period and to be used for power generation during less inflow season.
This means that knowledge of the change in water storage capacity of those reservoirs and lakes
is particularly important to evaluate the balance between availability and utilization of regulated
water energy and optimize the operation of hydropower plants. Moreover, for reservoirs built on
sediment loaded river system, repeated monitoring and analysis of deposited sediment in
reservoirs and lakes provide information on volume change to evaluate long-term changes in
storage capacity and assess potential reduction of benefits.
The presentation will focus on the techniques, methodologies and application challenges of
remote sensing based underwater mapping of reservoirs and natural lakes.
Renewable Energy Research Conference 2010 82

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Baseline Mapping of hydropower Resources for Climate Change and
other studies in a sparsely investigated catchment
Jjunju E a , Killingtveit Å b
a,b,
Norwegian University of Science and Technology(NTNU), Faculty of Engineering Science and
Technology, Department of Hydraulic and Environmental Engineering
The development of Renewable Energy resources such as hydropower is envisioned as a
key element for sustainable economic development, energy security and as part of the
solutions for curtailing the impacts of climate change. Hydropower as a renewable energy
source with proven performance is strongly advocated for developing countries where the
undeveloped potential is still high. However in many developing nations, access to
credible resource data still remains a challenge and inhibits the making of sound planning
decisions. Recent improvements in GIS and in the spread and spatial resolution of GIS
data provide an opportunity to improve the mapping of the hydropower resources. Such a
mapping in addition to being useful for comparing the economic feasibility of
hydropower vis-à-vis other renewable energy alternatives such as wind and solar also
provides a baseline for studying the impacts of climate change on the hydropower
system. This paper uses innovations in GIS to map hydropower resources using a case
study on the upper white Nile in eastern and central Africa. The results are compared to
existing site-specific records of hydropower potential for validation. A simple water
balance calculation for the past and for a future scenario under climate change is made
and the results compared to earlier coarse studies on the impact of climate change on
hydropower.
Keywords: Hydropower potential, GIS, Climate Change impact assessment baseline
Renewable Energy Research Conference 2010 83

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NTNU - SINTEF - IFE
European Hydropower Production Capacity – Study of the Correlation
between the Scandinavian system and Hydropower in the Alps, Balkan
and Iberia Regions.
By Ånund Killingtveit
Dep. of Hydraulic and Environmental Engineering, NTNU, Norway
Hydropower constitutes an important part of the electrical energy production system in
Europe. Scandinavia, the Alps region and Balkan have a high percentage of hydropower
compared to the total electrical production capacity. It is well known that hydropower
production can vary significantly, a result of highly variable hydrological conditions. This
was demonstrated very dramatically during the extremely dry autumn 2002 in
Scandinavia, where power price at NordPool rose to record levels during the end of the
year. The same situation seem to be reappearing now again in the winter 2009/2010.
Similar but less extreme events can be seen in the German power market where the
hydrological conditions in the Alps region can give significant effects on power price, in
particular during extreme dry/cold or wet/mild events. A modeling system has been
established in order to monitor and forecast hydropower production and hydrological
balance in these regions. Based on this model, a correlation study have been possible,
comparing energy inflow, hydrological storages and hydropower production capacity
within each region and between the regions. The analysis is based on >30 years of energy
inflow data compiled from Scandinavia (Norway and Sweden), the Alps region (Austria,
Switzerland, Germany and France) and the Balkan region.
Renewable Energy Research Conference 2010 84

The Centre for Renewable Energy
NTNU - SINTEF - IFE
Assessing the Water Temperature Variations and Ice
Conditions in Lundesokna: A Norwegian case study
Christophe Degouy a (christophe.degouy@gmail.com) 1 ,
Tor Haakon Bakken b (tor.haakon.bakken@sintef.no)
a ENSAM Paris Tech
b SINTEF Energy Research
Water temperature is recognized being an important factor for many biological processes
in riverine ecosystems (Caissie, 2003 2 ). River regulations change per se the natural flow
variation, in the very most cases changing also the natural water temperature regime. This
will, however, vary very much from case to case, depending on factors such as type of
regulation, location of reservoir, operational strategy, season and residual flow. Hydropeaking
is an extreme variant of hydro-power production introducing rapid and frequent
changes in the water flow possibly also causing similar rapid and frequent changes to the
water temperature. The objective is to focus on a practical case study to highlight the
correlation between anthropogenic activities and water temperature variations.
This case study is from Lundesokna, a small hydro-peaked river located approximately
30 kms south of Trondheim in Norway, extensively monitored during the severe winter
2009/2010. The 2.5 km long river were equipped with water level and temperature
loggers at 3 different locations from the outlet of Sokna hydro-power plant to the
downstream end at the confluence with river Gaula, logging at intervals as fine as 1
minute. These data were analyzed and compared with meteorological data and production
data (flow) from the upstream hydro-power plants. Moreover, manual mapping of the ice
production in the entire river was repeatedly carried out during the cold period and a GISdatabase
for further spatial analysis was established.
The study has documented the relation between the hydro-power operation and the
ambient water temperature in Lundesokna during a winter period with hydro-peaking.
Furthermore, a principle component analysis (PCA) has been carried out in order to
assess the importance of the various factors determining the water temperature and ice
conditions, and as a basis for the development of a statistical model. The study discussed
which statistical model suits better to the modeling of water temperature variations,
according to its specificities in terms of time scale and periodical ice presence.
Finally, the study has also assessed different ice mapping methods and discussed them in
terms of accuracy and rapidity.
1 This study was carried out as a master thesis with SINTEF Energy Research as the host institute and part
of the EnviPEAK-project (www.sintef.no/Projectweb/CEDREN/ENVIPEAK).
2 Caissie, D. 2006. The thermal regime of rivers: a review. Freshwater Biology vol 51, p. 1389–1406.
Renewable Energy Research Conference 2010 85

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A link between biological embeddedness factors and grain size
distribution for the evaluation of habitat quality of juvenile salmon
Stefan Jochama (stefan.jocham@gmail.com),
Tor Haakon Bakkenb (tor.haakon.bakken@sintef.no)
aUniversity of Stuttgart
bSINTEF Energy Research
A number of different physical parameters are used for the assessment of habitat quality
for juvenile salmon in running waters, i.e. substrate composition (Bovee, 19821). An
important characteristic of the substrate quality is embeddedness that can be regarded as a
spatial distribution of the underlying grain size distribution. Different approaches have
been developed to determine embeddedness with basically two different kinds of results;
ratios between the sample areas covered by finer and coarser material, and ratios between
the height of the layer of fine grain size sediments and the larger grain size sediments.
Although embeddedness was initially chosen as a parameter to measure habitat space for
juvenile stages of fish in running water, the results of the methods do not give direct
output to the requirements of fish. Thus it is of higher interest to measure directly the
interstitial spaces in the substrate in respect of habitat requirements. In this context
Finstad et al. (20072) developed a method to measure shelter for fish in running waters as
a parameter of embeddedness in a biological relevant aspect.
The goal of this study has been to develop a correlation between measured shelter and the
underlying grain size distribution in order to assess the long-term development of the
substrate quality by use of predictive models. The approach of finding the correlation
between shelter and grain size distribution was conducted by gathering data in
representative places for both shelter numbers using the Finstad method and grain size
distributions using a photo-sieving approach.
Candidate parameters for comparing data and establishing correlations are characteristic
grain sizes like D50 and D90 related to the grade of fines. This is implemented in the
skewness of a typical grain size distribution curve. These parameters can be regressed
with found shelter spaces regarding the number and depth.
The findings of this study3 contribute to the general understanding of morphological
processes and their potential ecological impacts and can be used for the development
ofassessment and management tools for hydro-peaked rivers.
1 Bovee, K.D. 1982. A guide to stream habitat analysis using the Instream Flow Incremental Methodology.
U.S. Fish and Wildlife Service FWS/OBS-82/26. 248 pp.
2 Finstad, A.G., S. Einum, T. Forseth. & O. Ugedal. 2007. Shelter availability affects behaviour, sizedependent
and mean growth of juvenile Atlantic salmon. Freshwater Biology, Vol 52 Issue 9, Pages 1710 - 1718.
3 The work is carried out as a diploma thesis with SINTEF Energy Research as the host institute and as part
of the EnviPEAK-project (www.sintef.no/Projectweb/CEDREN/ENVIPEAK)
Renewable Energy Research Conference 2010 86

The Centre for Renewable Energy
NTNU - SINTEF - IFE
Comparison of Evapotranspiration derived from GCM Latent heat flux
with that from land-use characteristics and meteorological records.
Emmanuel Jjunju 1 , Ånund Killingtveit 2 , Knut Alfredsen 3
123 Norwegian University of Science and Technology
Modelling the impacts of climate change on stream-flow under future climate-change
scenarios relies on downscaled precipitation and temperature data from Global Climate
Models. Evapotranspiration is also important especially for many tropical and subtropical
areas. Most of the current GCMs do not provide direct estimates of potential Evaporation
(PE) but provide the latent heat flux (hfls) at the respective models' resolutions from
which evaporation can be estimated at the model's spatial resolution. However within an
individual GCM grid-cell, the land cover may vary spatially and for modelling exercises
focusing on areas which are much smaller than a GCM's model resolution, the
evapotranspiration based on the large grid cells may not be very representative. Besides,
GCMs do not incorporate the effects of land use change which are known to to have an
impact on the hydrological cycle especially on evaporation (through controlling surface
and aerodynamic resistance). Herein a case study from Uganda is used to compare GCM
derived estimates of evapotranspiration with locally computed values derived using the
Penman Monteith approach on meteorological data and land cover characteristics. The
study is relevant for deciding how to incorporate land-use change in impact studies of
future climate change that rely on hydrological modelling.
Renewable Energy Research Conference 2010 87

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NTNU - SINTEF - IFE
ABSTRACTS
Bioenergy
Renewable Energy Research Conference 2010 88

The Centre for Renewable Energy
NTNU - SINTEF - IFE
Abstract title: Variations in Norwegian biomass quality
Author(s): Judit Sandquist
Organisation: SINTEF Energy Research
Biomass is the second greatest renewable source of energy, and it is mostly used to give heat
(and electicity) by combustion. Biomass applications are dependent on biomass
characteristics, and the smaller the plant the more dependent it will be. Biomass combustion
gives an impact on not only the environment but the combustion plant itself. This impact is
dependent on not only the conversion technology but the raw material as well. Firstly, the
different biomass species and biomass parts has different characteristics and secondly,
biomass fuels are special fuel as they are living organisms and need nutritions to grow. The
nutrition levels are dependent on for example, soil, precipitation, climate and fertilisation, and
even the same species can give different combustion characteristics if they are grown on
different locations due to different levels of trace elements.
Trace elements, as K, Ca, S, P, Si, Mg, etc. influence both the ash composition and corrosion
and fouling in the process plant. NO x and SO x emissions are mostly determined by the N and
S levels of the fuel, respectively. The main element compositions show variations mainly in
different biomass parts and species.
The aim of this literature study is to map the variations in Norwegian biomass quality and
quality variations based on available publiced information. The quality variation
determination will be approached by the element levels in biomasses and biomass ashes
mostly. Comparison between the different biomass species, parts, locations and fertilisation
methods will be shown.
Renewable Energy Research Conference 2010 89

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NTNU - SINTEF - IFE
Effect of whole-tree thinning on long-term forest growth
Kjersti Holt Hanssen and Bjørn Tveite
Norwegian Forest and Landscape Institute, P.O. Box 115, NO-1431 Ås, Norway
kjersti.hanssen@skogoglandskap.no, bjorn.tveite@skogoglandskap.no
Introduction
The demand for forest biomass for bioenergy is increasing, and the use of logging residues for
forest chips is encouraged in many countries in Europe. However, as needles and branches are
nutrient rich, this whole-tree harvesting (WTH) increases the export of nutrients from the site.
There is concern that removal of logging residues may cause a long-term reduction in soil
nutrient availability, reducing forest growth in the remaining stand. Some studies have shown
growth reduction after WTH in thinnings as well as in final harvesting (Jacobson et al 2000,
Egnell and Valinger 2003), while others have not found significant effects on growth (Egnell
and Leijon 1997, Mård 1998). The response seems to be variable, and site- as well as speciesspecific.
There is a need for long-term growth results to assess the sustainability of intensive
biomass harvesting. The objective of this study was to quantify the long-term growth response
of Norway spruce (Picea abies) and Scots pine (Pinus silvestris) to whole-three harvesting at
first thinning.
Methods
In 1972-1977 a series of eight field experiments was set up in young Norway spruce and
Scots pine sites in SE Norway. In the stands, thinning plots using both conventional (CH) and
whole-tree harvesting were established, with five replicates of each treatment. The pine stands
were thinned to 800 trees ha -1 , while the spruce stands were thinned to 1100 trees ha -1 . The
amount of dry matter and nutrients removed in the thinning was computed, and tree growth
was measured each 5 th year. Growth increment was analysed separately for spruce and pine
plots, using analyses of variance to compare the two treatments.
Results
For spruce, WTH has lead to a decrease in forest growth in all sites after 25 years. On
average, the reduction is around 10 % compared to CH, if adjusted for initial differences in
standing volume. The difference is statistically significant. In the pine stands, the results were
more variable between stands and periods. After 25 years there was a non-significant average
growth reduction of 3 %, adjusted for initial differences in standing volume.
The results show that growth reduction in spruce stands after WTH is present at least 25 years
after thinning. Also Jacobson et al (2000) and Egnell and Leijon (1999) found a more explicit
growth reduction after WTH in spruce compared to pine stands. When transferring the results
to practical silvicultural measures, one should consider that these results are generated under
experimental conditions. In practice, a share of the residues is left on site during harvesting,
decreasing nutrient loss compared to a total removal of branches and tops.
References:
Egnell, G. and Leijon, B. 1997. Scand J For Res 12: 17-26.
Egnell, G. and Leijon, B. 1999. Scand J For Res 14: 303-311.
Egnell, G. and Valinger, E. 2003. For Ecol Manage 177: 65-74.
Jacobson, S., Kukkola, M., Mälkönen, E. and Tveite, B. 2000. For Ecol Manage 129: 41-51.
Mård, H. 1998. Scand J For Res 13: 317-323.
Renewable Energy Research Conference 2010 90

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BioEnergy Planning – Optimization under Uncertainties
Dipl.-Kfm. Harald Uhlemair a (harald.uhlemair@wiwi.uni-goettingen.de),
Prof. Dr. Jutta Geldermann a (geldermann@wiwi.uni-goettingen.de)
a Georg-August-Universität Göttingen
Increasing CO 2 emissions and the emerging scarcity of fossil raw materials bring
resource efficient concepts more and more into the focus of public interest. One resource
efficient concept was realized in the German ‘bio-energy village’ Jühnde by using
biomass instead of conventional energy sources to meet the electricity and heat demand.
Electricity and heat are produced by burning biogas in a combined heat and power
generator (CHP). Liquid manure and crops, cultivated on the agricultural land around the
village, are the feedstock for the generation of biogas in an anaerobic digestion plant. The
electricity is fed to the national electricity grid. The idea of a nearly self-sustaining
village based on biomass energy sources could be an important basis for a resource
efficient energy strategy.
For estimating the economic consequences of a bio-energy village, techno-economic
optimization models can be used. They provide the ‘cost optimal’ energy supply over a
given planning horizon. A linear programming optimization model is used, in which the
size of the biogas plant and the heat network are optimized simultaneously. To start with,
the model optimizes the process for a specific village. In a second step, this model is used
to extract a more generalized optimization model, which then can be customized for other
regions.
Furthermore, any modeling is subject to various sources of uncertainty, like “data
uncertainties”, “parameter uncertainties” and “model uncertainties” (spatial variability,
temporal variability and variability of sources). Therefore, different types of uncertainties
related to the use of biomass are analyzed and reflected in the model.
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Renewable Energy Research Conference 2010 92

The Centre for Renewable Energy
NTNU - SINTEF - IFE
Apparent Pyrolysis Rate of Large Biomass Particle in High
Temperature Steam Flow
Kentaro Umeki (kent.ume@gmail.com),
Amit Kumar Biswas (akbiswas@kth.se),
Weihong Yang (weihong@kth.se)
Royal Institute of Technology (KTH)
Objective: To investigate the apparent pyrolysis rate of large biomass particles when
biomass is heated by highly preheated steam. To develop the simple, but practical rate
expression of apparent reaction rate after investigating the significance of the effect of the
chemical reaction rate, internal heat transfer (conduction), and external heat transfer
(convection and radiation).
Methodology
Cylindrical-shaped wood particles with different diameters were used in this
research. The diameters of sample are 20, 25 and 30 mm, and the length is 50 mm.
The experimental setup mainly consists of a burner, a combustion chamber, a
boiler, a ceramic heat storage bed, a gasification chamber and a gas exhaust. At first, the
ceramic heat storage and the gasification chamber were heated by combustion gas of
natural gas and air. When the temperature of 100-150 K above the desired temperature
was observed at the thermocouple located in the gasification chamber, the burner was
turned off and steam started to be fed into the gasification chamber through the heat
storage bed. After the gasification chamber was purged by steam, sample held in the
wire-mesh basket was put into the gasification chamber. The temperatures of gasifying
agent and the particle centre and the residual mass of the sample basket were measured
every second during the gasification experiments.
Outline of results
From the experimental investigation, particle was heated at a high heating rate
and lost its mass faster when the particle size was small and the steam temperature was
high. The final temperature of the particle centre was affected only by the steam
temperature. The heating rate of the particle centre was limited mainly by the external
heat transfer for the particle of 20 mm in diameter, while it was limited by the internal
heat conduction for the particle of 30 mm in diameter. The pyrolysis time was shorter at
a smaller sample size and a higher steam temperature. The char yield decreased as the
steam temperature increased. The char yield was not affected by the sample size in this
study. The apparent pyrolysis rate was calculated by applying the shrinking core model.
The model showed good agreements with experimental results. Predicted Biot number
indicated the transition of the rate limiting step from the external heat transfer to the
internal heat conduction when the particle diameter increased.
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Study of the slow batch pyrolysis of mixtures of pine, plastics and
tires. Application of Response Surface Methodology.
Filipe Paradela a (filipe.paradela@lneg.pt), Filomena Pinto a
(filomena.pinto@lneg.pt), Ana M. Ramos b (ana.ramos@dq.fct.unl.pt) and Ibrahim
Gulyurtlu a (ibrahim.gulyurtlu@lneg.pt)
a Laboratório Nacional de Energia e Geologia
b Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa
The aim of this work was to optimise pyrolysis experimental conditions of three types of waste in
a batch reactor, particularly the influence of the reaction time, temperature, initial pressure and
waste mixture composition in the yield and composition of liquid products. The wastes studied
were. biomass (pine), used tyres and recycled plastic, whose main components were polyethylene
(PE), polypropylene (PP) and polystyrene (PS).
Experimental tests were made in a 1L stainless steel autoclave, in which the experimental
conditions like: initial pressure, waste mixture composition, temperature and time of reaction
were varied and optimized. The three product fractions obtained (liquids, solids and gases) were
collected and analyzed. Two immiscible liquid phases were formed whenever pine was
pyrolysed, one being mainly water with traces of compounds commonly produced by fast
biomass pyrolysis, and the other being a less dense organic phase. Liquids were distilled into
three fractions. The lighter one distilled between 35 and 150 °C, the next fraction distilled
between 150 and 270 °C, whilst the other presented a distillation range higher than 270 °C. Each
fraction was analyzed by Gas Chromatography (GC) and GC/MS (Mass Spectrometry) to
identify their main compounds. Gases were also analyzed by GC and its density was also
measured. The remaining liquid in the solid phase was extracted with solvents and analyzed by
GC.
Liquid products yield and composition were affected by experimental conditions. Previous
studies (1) showed that the rise of reaction temperature decreased liquid yields, by increasing
solids and gases yields. The increase of initial pressure did not lead to significant variations in
products yields and composition. The increase or pyrolysis reaction time led to a small decrease
in liquids formation, favouring the production of lighter liquid compounds. The optimisation of
experimental parameters was done by response surface methodology (RSM), which allowed
identifying the inter-relations between the experimental variables and optimising simultaneously
the three variables studied. Experiment Factorial Design was used and the experimental results
for the yield of liquids were fitted with a linear model by the method of least squares with good
correlation and high statistical significance. According to the model, the production of pyrolysis
liquids is maximized when the following conditions are used: reaction temperature of 450ºC,
reaction time of 23 minutes and initial pressure of 0.51MPa for a waste mixture consisting of
80% plastics, 10% pine and 10% tires.
(1) Filipe Paradela, Filomena Pinto, Ana M. Ramos, I. Gulyurtlu, I. Cabrita, J. Anal. Appl.
Pyrolysis 85 (2009) 392–398.
Renewable Energy Research Conference 2010 94

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Molten Salt Pyrolysis of Biomass
Heidi S. Nygård a (heidi.nygard@umb.no),
Espen Olsen a (espen.olsen@umb.no)
a Department of Mathematical Sciences and Technology
Norwegian University of Life Sciences
1432 Ås, Norway
Molten salt pyrolysis of biomass is a concept based on dispersion of biomass particles in
a molten salt bath in the absence of oxygen. The inorganic salts used in the process have
very high heat capacities and good thermal stability at high temperatures, qualities that
promote flash pyrolysis in order to give high yields of bio-oil. The catalytic properties of
the salts will also give simpler product mixes compared to other pyrolysis methods. In
addition, molten salts will retain noxious contaminants, which makes it possible to use
difficult convertible- and/or contaminated biomass as feedstock. An experimental setup
for the process is shown in figure 1.
Figure 1 – Experimental setup for pyrolysis of biomass in molten salts
We present a review of results from published studies and preliminary results from the
construction of a laboratory reactor.
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Renewable Energy Research Conference 2010 95

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NTNU - SINTEF - IFE
Status for standards on wood- and pellet stoves and needed
improvements
Edvard Karlsvik, Bjarne Malvik, Franziska Goile
SINTEF Energy Research, , Sem Sælands vei 11, NO-7465, Trondheim, Norway
There is increasing interest for solid bio fuels like wood logs and pellet, as a substitute
for fossil fuels used in domestic heating appliances. Small stoves and fireplaces,
burning wood logs and not pellet, are characterized by batch fuel loading and a
varying combustion cycle. A consequence may be periods with high flue gas
emissions, especially regarding condensed combustion particles. In densely built up
areas, cold days with extensive use of wood burning appliances, may cause reduced
ambient air quality and be a treat to public health.
A review of existing standards for type testing of small wood and pellet stoves, both
national and international, have shown that test procedures and requirements
concerning fuel loads, emissions and efficiency are different. The differences
between standards may seem small, but when including the options for individual
practice and judgment, the result can be emission factors differing by more than five
times for the same product. This should call for action, aiming at better harmonized
test procedures.
Even if type testing after different standards/test procedures gives the same results,
the fact that all test methods are not approved in all markets is an obstacle to market
access. The promotion of free competition, especially within the EU-area, should
speed up the harmonisation work. However, national permissions to practice stricter
regulations and the existence of voluntary certification schemes focusing on
environmental impacts seem to be both pressing the emission limits and forcing the
manufacturers to test their products for every market they want access to.
Needed measures to achieve adequate documentation of combustion efficiency and
emission of pollutants at different loads may be:
Further tightening of the standards for small wood heating appliances in order
to avoid interpretations of given requirements and thereby allowing for “local
routines” in the test laboratories.
Reducing the number of standards or harmonize standards.
Testing at low loads should be mandatory, especially for particulate emissions.
Testing at low loads in order to achieve a better documentation of the real life
combustion efficiency.
Agreeing on one common method for measuring particles. This is important
for documenting emissions of respirable particles from small wood log and
pellet burning appliances.
All test methods should describe procedures for determination of particles,
CO, OGC. In the years to come, the number of pollutants will have to be
extended (PAH, dioxins e.g.).
Renewable Energy Research Conference 2010 96

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AE&E Group
Elmar Offenbacher
Director Global Sales – Nordics & Baltics
NTNU - SINTEF - IFE
Abstract for Renewable Energy Research Conference 2010:
Sustainable Generation of Bioenergy
in Fluidised Bed Boilers
These days, reflecting a growing demand of heat and power, increasing cost for fossil
fuels and more environmental issues (limitation of greenhouse gases, regulations for
landfill etc.), the sustainable conversion of renewable fuels to bioenergy is becoming
increasingly important. Renewable fuels cover a wide range, from traditional wood,
bark, harvesting residues to all kind of sludges, and contain a remarkable calorific
value that can easily compete with fossil fuels such as brown coal and lignite. The
combustion of these renewable fuels does not create any greenhouse gases.
The favourable technology for combusting renewable fuels is the fluidised bed
technology, bubbling fluidised bed and circulating fluidised bed, as this system
provides maximum fuel flexibility combined with high combustion efficiency and
low emissions. Neither a variation of the water content and the heating value nor
different sources of the material streams have a negative impact on the combustion.
Fluidised bed boilers can switch from one fuel to the other quiet easily and can also
be fired with conventional fuels that ensure a smooth and reliable generation of
process heat and/or power in any case.
The reasons that make fluidised bed boilers the most sustainable combustion
technology for renewable fuels are various: The main feature of this technology is
the principle of staged combustion of the fuel: The oxygen level in the fluidised bed
is limited and hence only a part of the fuel is combusted, whereas the rest of the fuel
is gasified. The staged combustion concept results in a homogenous temperature
profile of less than 850°C in the furnace and low NOx emission as a consequence.
The turbulences in the furnace result and an efficient combustion that is combined
with very low CO and TOC emissions in the flue gas.
This paper will describe design features of the latest fluidised bed technology
especially suitable for firing renewable fuels, and the research results of further
reducing the emission levels. Beside that the paper will also informs about the
experience gained in several reference plants with various fuels, including the
world’s first fluidised bed boiler to burn poultry litter and one of the world’s most
efficient power plants to exclusively burn biomass, demonstrating that fluidised bed
boilers are the most sustainable technology for generating bioenergy.
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Tubular reactor for gasification of sawdust and powder biomass for Energy
applications
Dr.K.C.Mohite, Email: kcmohite@gmail.com
1.Director, University of Pune , UAE Campus, RAs Al Khaimah,UAE
2.Adjunct Professor, School of energy Studies, University of Pune, India
ABSTRACT
Biomass has already recognized as an ideal resource for the decentralized energy systems, due to
its availability in the remotest of the locales. Direct combustion of biomass has been an old
practice. Among various agro residues, light biomass has vast potential but not utilized up to its
full extent. However, the conversion of raw biomass into energy for variety of applications
through biological and Thermo-chemical conversion processes is relatively a recent
phenomenon. The gasification and pyrolysis of solid materials have been used extensively to
produce fuels such as charcoal, coke and town or producer gas. In the case of charcoal for
millennia and coke for something like the last 200 years.
The Gasification of biomass is greatly influenced by its physicochemical nature, ash properties,
content and rate of evolution of volatiles, moisture content, fixed carbon, etc. The biomass
feedstock for gasification should have low moisture contents (up to 10 %), low volatile matter,
low ash content (up to 10%), but high ash fusion temperatures (above 1200 C).In applications
requiring maximum conversion of feedstock to gas, the tubular reactor has several advantages
over other conversion technologies. The tubular reactor subjects the feedstock to very rapid
heating rates, of the order of 10000 0 C /s thereby minimizing char and tar production and
maximizing gas production especially the valuable unsaturated hydrocarbons.
A versatile, compact and economical down flow entrained tubular reactor is designed and
developed for these studies. The wood particles used in the experiment consists of a seasoned
sawdust. Feed rate of 40 gm/min is used. The elemental analysis and characterization of the feed
and effluent products are made. The purpose of this study is to develop the process chemistry for
the rapid pyrolysis of biomass which include agricultural products with both reactive (H 2 , CO,
CO 2 , CH 4 , C 2 H 4 , & C 2 H 6 ) and not reactive (N 2 ) gases for the production of gaseous
hydrocarbon fuels and feedstock.
The Feeding rate of sawdust/wood particles is 40 gm/min and the quality of the gas obtained is in
the category of Low Joule value (L.J.V) gas. Calorific values, 4.45, 4.63 and 4.89 MJ/m3 are
observed at the system temperatures 800, 900 and 1000 0 C respectively The conversion efficiency
and overall efficiency of the tubular reactor at 900 0 C zone temperature are 84.70% and is ~ 77.40
% respectively.
This paper deals with the study of potential of biomass as source of energy and Challenges in
carbonization and gasification of biomass for Energy applications.
Key Words: Thermo chemical route, Powder Biomass, Gasification, Pyrolysis
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Using Biomass for Combined Heat and Power as a method for
improving Energy Efficiency in Serbian Industry
Marta Trninic a (trninic@stud.ntnu.no),
Morten Grønli a (morten.g.gronli@ntnu.no),
Øyvind Skreiberg b (oyvind.skreiberg@sintef.no),
Goran Jankes b (gjankes@mas.bg.ac.rs),
Mirjana Stamenic b (mstamenic@mas.bg.ac.rs)
a Department of energy and process Engineering, Norwegian University of Science and
Technology (NTNU), Kolbjørn Hejes vei 1A, NO-7491 Trondheim, Norway
b SINTEF Energy Research, NO-7465, Trondheim, Norway
Serbia has highly import dependence of primary energy sources, 3.020 million teo (oil and
natural gas), while on the other hand, biomass resources represent a significant potential of
primary energy source, but it is insufficiently used. The overall biomass energy potential in
the Republic of Serbia is estimated at 2.7 Mtoe per year. Agricultural residues are the main
biomass renewable sources. The most widely planted agricultural crops in Serbia are corn.
The possible thermochemical conversion of biomass is gasification. This paper presents
environmental and economic benefit of using biomass instead of fossil fuels in order to meet
energy demand with combined heat and power production. Surveying the biomass potential,
one concept of using biomass as energy is to design and construct the demo plant for biomass
gasification with combined heat and power generation with installed power of 1MW. Material
and energy balance of gasification plant shows that the efficiency of gasifier up to 90% can be
expected, while the efficiency of cogeneration plant can be in range of 77-80%.
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APP – Fiborgtangen Vekst,
Biomass Energy from Waste Project
Technology base and rationale for the process
In response to the challenges associated with global climate change, the European
Commission has set ambitious legislative targets, which member states are obliged to
achieve, to greatly increase the proportion of electricity generated from renewable
sources. The Commission has also sought to encourage best practice in the management
of wastes which includes reducing the proportion of biodegradable material sent to
landfill and the recovery of recyclates and (renewable) energy from the waste.
Against this background, APP has developed an advanced thermal conversion technique,
(Gasplasma), capable of treating a wide range of organic containing wastes. In the twostage
thermal process, the fluidised bed gasifier (FBG) converts the waste to a crude
syngas containing significant levels of char, ash, tars and other liquid organic
contaminants. This gas stream, together with the char and ash product from the gasifier,
is then treated in a high temperature plasma converter unit to produce a reformed and
consistent quality synthetic gas (syngas) which (after tertiary cleaning of the acid gases
and particulates) is suitable for high efficiency generation of power in a gas engine or gas
turbine. The inorganic ash fraction is vitrified in the plasma converter unit to produce a
dense, environmentally stable vitrified product (Plasmarok).
The hydrogen rich syngas from the process contains very low levels of tars which (in
addition to high efficiency power generation) would alternatively be suitable for the
production of liquid fuels or renewable hydrogen.
An important aspect of the design concept was to employ commercially tried and proven
techniques. The breakthrough innovation stems from how these technologies have been
effectively integrated to enable the economic production of a clean syngas and secondary
aggregate.
Main steps in the development of the demonstration plant
The initial technical approach considered was to employ a single stage thermal plasma
process, where gasification of the solid fuel, vitrification of the ash and refining of the
syngas occurred within the same vessel. Pilot tests showed that although this approach
was technically feasible, the productivity of the gasifier in this configuration was low
which meant that the power requirement and capital cost for a projected commercial plant
would have been prohibitively high.
A fundamental rethink of the entire thermal process was instigated which led to the
concept of the twin stage design for Gasplasma (as described above). The rationale that
underpins the Gasplasma process is that the operating conditions within the FBG ensure
the high heat transfer and reaction rates required to efficiently gasify the solid fuel, whilst
the plasma converter provides a high temperature and intense UV light environment for
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cracking and reforming of tars/chars and also for vitrification of the ash forming fraction
of the fuel. A thermodynamic computational model of the process was also developed at
this stage, where it was established that there would additionally be significant technical
and economic benefits by using oxy-steam rather than air at the gasification and plasma
converter stages.
In initial “proof of concept” pilot tests that were conducted, the gas was analysed
downstream of the plasma converter before being combusted in a thermal oxidiser. This
work showed that:
It was possible to produce from an RDF feedstock a consistent, reproducible
and acceptable quality of syngas (i.e. suitable for use as a feed to a gas engine
or gas turbine) with high gasification yields. There was also good correlation
between observed and theoretically derived values in respect of the syngas
composition and flowrates.
The vitrified product generated from the process was environmentally stable,
with end use potential. In particular the material complied with the leachate
standard BS EN 12457, as specified under the Waste Acceptance Criteria
(WAC) for inert landfill.
Subsequently, a new demonstration facility was designed and installed, when APP
moved to their current site in Swindon, which is a fully integrated plant similar in design
and operation to the planned commercial Gasplasma facility. The extensive trial work
that has been undertaken on this plant has demonstrated that syngas of a consistent,
predictable and controllable quality for feeding to the gas engine is generated.
Furthermore, the progressive implementation of automated systems has improved the
controllability of the system and has greatly reduced the degree of human intervention
required in running the process.
Main technology challenges
The electrical conversion efficiency that can be achieved using a gas engine is c.40%
compared to 25% for a steam turbine system (at an equivalent thermal input). In the past,
it has been the problem of tar and char contamination of the syngas, associated with
conventional gasifiers, that has prevented the widespread adoption of waste gasification
to power gas engines and turbines.
One of the major technical challenges that has been met in the operation of the Swindon
facility has been in demonstrating the integration of the main process elements, namely
the gasifier, plasma converter, gas cooling/clean-up and the engine to achieve a complex
interdependent system that meets the plant design specification and most critically,
produces a syngas that can be utilised directly in a gas engine/turbine.
The challenge faced with scale-up of the technology has been addressed in the
engineering of the commercial plant. The technological risk has been greatly reduced by
incorporating operating units (ie gasifier, plasma converter and gas engine) that have
individually been tested at similar ratings proposed for the commercial plant. Extensive
Computational Fluid Dynamic (CFD) modelling has been undertaken to develop an
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optimal design for the plasma converter, especially in ensuring high capture efficiency of
ash particles and avoidance of any short circuiting of syngas exiting the converter offtake.
There are also significant opportunities for utilising the syngas in other applications, for
example, in the production of bio-jet fuels using syngas as a precursor in a Fischer
Tropsch (FT) process. In this case there would be a number of technical challenges to
overcome in developing a robust commercial solution. For example, further refining of
the syngas would have to be undertaken, reducing the sulphur gas impurities to the
extremely low (ppb) levels required in the synthesis reaction. In addition, conditioning of
the gas using the Water gas shift reaction will be needed to produce the required H2/CO
ratio for the FT reactor. The integration of multiple Gasplasma trains would also be
necessary in order to attain acceptable economies of scale.
Integration with a large scale bio-power plant as in Norske Skog Skogn
The Norske Skog Skogn paper mill needs approximately 600 GWh of heat in addition to
that which is produced as heat recovery from the TMP process. The excess heat
generated by the Gasplasma process will partially offset this additional demand and will
be utilised to supplement the sites process steam requirements, which range in quality up
to 55 bar and 500 o C, to low grade heat in the form of hot water for district heating.
Production of electrical power locally in the NO3 area will have a significantly positive
effect on the extremely tight supply situation in the national grid. The residual heat
within the exhaust gases will be recovered by further processing in the existing CHP
biomass boiler plant.
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Research results from a prototype for power generation from
low temperature heat sources in small and medium sized
sawmills
Tor-Martin Tveit a (tmt@sppower.no),
Arne Høeg a (ah@sppower.no),
Trond-Atle Asphjell a (taa@sppower.no),
Henning Horn b (henning.horn@treteknisk.no)
a Single-Phase Power AS, Jacob Neumanns vei 15, NO- 1384 Asker, Norway
b Treteknisk, Forskningsveien 3B, P.O. Box 113 Blindern, NO-0314 Oslo
In this paper we present research results from a low temperature power generation unit
prototype, SPP 2-67A, installed at the timber company Moelven Eidsvold Værk in
Norway. The power generation unit is a stirling cycle reciprocating engine connected to
a generator, which is designed to combine the mature technology for high temperature
stirling engines (as seen for instance as air independent propulsion (AIP) units in
submarines) and recent academic work on low temperature stirling engines.
The power generation unit is installed in a boiler room at the Moelven Eidsvold Værk
plant and uses steam at approximately 1.5 bar pressure as a heat source. The steam is
generated in the 5.5 MW biomass-fuelled boiler, where bark of Norway spruce (Picea
abies) is the main biofuel. The installation has been intended both to use hot water as a
heat sink to demonstrate CHP operation, and cold water from the grid to demonstrate
maximum power generation from surplus steam.
Figure 1 – Picture of the power generation unit installed at the sawmill.
The installation is part of a research project partly financed by the Research Council of
Norway, with the goal of testing new technology to improve the use of bioenergy
resources and conversion of heat from biofuels to power.
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Ash related behavior in staged and non-staged combustion of biomass fuels and
fuel mixtures
Øyvind Skreiberg 1,1 , Dusan Todorovic 2 , Roger A. Khalil 1 , Rainer Backman 1 , Michaël
Becidan 1 , Franziska Goile 1 , Alexandra Skreiberg 1 , Alexander Jovovic 2 and Lars
Sørum 1
1) SINTEF Energy Research, Sem Sælands vei 11, NO-7465, Trondheim, Norway
2) University of Belgrade, 11000 Belgrade, Serbia
Abstract
The fate of selected biomass ash elements are investigated for three biomasses (wood,
demolition wood and coffee waste) and six mixtures of these as pellets both with and
without air staging in a grate fired laboratory reactor. In order to get a complete
overview of the combustion products, both online and offline analytical methods are
used. Information is collected about: flue gas composition, particle (fly ash) size
distribution and composition, bottom ash composition and melting properties. The
main findings are: (a) complex interactions are taking place between the mixed fuels;
(b) the mode of occurrence of an element as well as the overall structure of the fuel
are important for speciation; (c) the pelletization process, by bringing chemical
elements into intimate contact, may affect overall chemistry (partitioning and
speciation); (d) the differentiated experimental behaviors of the two alkalis in biomass
(with staging and mixing) is clearly shown in this study; it has never been reported to
our knowledge; (e) a given technique (staging, mixing) might simultaneously have
positive and negative effects on operation; (f) staging affects the governing
mechanisms of aerosols formation; (g) experimental challenges are many but do not
prevent from discovering strong underlying trends.
Keywords: Biomass, Fuel mixtures, Staged combustion, Bottom ash, Fly ash, Gas
composition, ELPI, Particle size distribution
1 Corresponding author: Oyvind.Skreiberg@sintef.no
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Emission Control through Primary Measures in Biomass
Combustion
Ehsan Houshfar a (ehsan.houshfar@ntnu.no),
Øyvind Skreiberg b (oyvind.skreiberg@sintef.no),
Terese Løvås a (terese.lovas@ntnu.no)
a Norwegian University of Science and Technology
b
SINTEF Energy Research
Biomass as one of the renewable sources of energy and the only carbon containing
renewable resource is known as a collective term for many different forms of combustible
material derived from plant sources. It can be material that has been taken from a primary
production process (chip wood from forestry) or re-claimed material (such as used, clean
untreated pallets, waste …). To utilize biomass, the conversion pathway could be done in
three different ways: thermochemical, biological and physical. Thermochemical technology
(including pyrolysis, gasification and combustion) is the most widely used technology to
utilize biomass.
In addition to the three main elements: O, H and C as the major part, there are also some
other minor or trace elements included in the biomass structure such as N, S, Cl and ash
elements, contributing to emissions and operational problems (e.g. corrosion and fouling)
To avoid emissions, both primary measures and secondary measures can be used. Primary
measures are used to avoid creation of these emissions, while secondary measures remove
the emissions from the exhaust gas. Thus primary measures are dealing with the
combustion zone and improvements to this area, while secondary measures look at the exit
of combustion chamber, i.e. the flue gas, to reduce the emission levels.
Incomplete combustion of biomass will lead to carbon monoxide, hydrocarbons, particulate
matter and polycyclic aromatic hydrocarbons, while complete combustion will lead to NOx
and SOx emissions. SCR and SNCR are common secondary measures to reduce NOx
emissions.
LCA studies have shown that the main pollutant from wood combustion will be NOx, with
an emission impact factor as high as 38.6%. Staging technologies (i.e., air-staging and fuelstaging)
and flue gas recirculation are possible primary measures to reduce the NOx
emission level from biomass combustion. Staged air combustion is maybe the most
effective method of NOx emission reduction by primary measures. It can reduce the NOx
emission level with up to 50-70 percent at an optimum primary excess air ratio.
In the present work, primary measures for emission reduction in biomass combustion
technologies such as air-staging, with emphasis on NOx, and the effect of each measure is
identified both experimentally and numerically in a comparative study.
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Life Cycle Assessment of bio-fuelled Combined Heat and Power
Plants— Centralized versus Decentralized deployment strategies.
Geoffrey Guest*
Ryan Bright
Francesco Cherubini
Ottar Michelsen
Anders Hammer Strømman
*corresponding author: geoffrey.guest@ntnu.no
NorwegianUniversityofScience&Technology
DepartmentofEnergyandProcessEngineering
IndustrialEcologyProgramme
Høgskoleringen5,7491Trondheim,Norway
The growing and accumulating boreal forest stocks of Norway over the past several
decades and the need for renewable energy has created an increased drive for Norway to
develop its bioenergy sector. One technological option that this research considers is
combined heat and power (CHP). Norway’s space heating and electricity needs are
predominantly fuelled by their vast hydro power resources. CHP from biomass however,
offers a renewable, non-intermittent, base-load energy source which not only reduces
electricity derived space heating needs but also offers increased low-carbon electricity
exports to the rest of Western Europe of whom have an electricity mix dominated by
fossil fuels. This study focuses on a local regional perspective situated in middle-
Norway’s Nord- and Sør-Trøndelag counties. Life cycle assessment methodology is used
to compare the environmental impacts of three differing scales of CHP production—
medium (50 MW el.cap ), small (1 MW el.cap ) and micro (0.1 MW el.cap ). Additionally, a
measure to compare the socio-economical benefits to a community is offered as a way of
quantifying the relative communal prosperity of each scale of energy source. By
comparing the impacts that these three CHP units have from utilizing locally sourced
biomass, the pros and cons of each scale was determined. The most characteristic
differences in impact will be due to differences in transportation distances needed for
biomass procurement and electricity distribution due to electricity grid losses at differing
voltage levels. The results from such an analysis are expected to aid in determining the
most environmentally sustainable heat and power plant scales for implementation in
sparsely populated regions with surplus wood residue resources.
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Review of Additives Used for Abating Ash Related Problems in
Biomass Combustion
Liang Wang a (liang.wang@ntnu.no),
Johan E. Hustad a (Johan.e.hustad@ntnu.no),
Geir Skjevrak a (GSS@statoil.com),
Christer Heen Skotland b (christer.heen.skotland@ntnu.no)
a Department of Energy and Process Engineering, Norwegian University of Science and
Technology
b Centre for Renewable Energy
Biomass combustion has a remarkable potential in meeting the energy demand with an
additional importance concerning the global warming, since it is CO 2 neutral. However,
the ash from biomass with high alkali metals and chlorine could lead to ash related
problems e.g. agglomeration, slagging, fouling deposits and high temperature corrosion.
These problems have been often observed in biomass fired plants and resulted in high
costs cleaning and/or shutdown with reduced publicity of biomass combustion. As one of
effective solutions, numerous publications are concerned with additives introduced in
biomass combustion process in order to abate or eliminate the ash related problems. This
work is a survey on current knowledge and status about the selection and application of
additives for different biomass combustion technologies. An updated list of additives
used in various research activities is provided for further summarization and comparison.
The anticipated effects from various additives have been reported or can be suspected: 1)
chemical adsorption of alkali metals into new compounds with high melting points, 2)
physical adsorption of vapour and melted species by additives with high porosity, 3)
reduction of ash melted fraction and the melting process with inert elements dilution, and
4) restraining the contact and accumulation of ash melts with grindable and powdering
effects from additives. Special emphasis is given to the minimizing of additives on
biomass ash related issues by chemical reaction/interaction. The efficiency of different
additives strongly depends on the mass/mol ratio between the reactive components in the
additives and problematic elements in the biomass ash, as well as the atmosphere and
combustion technologies. The size distribution and specific surface areas have the extra
influence on additives performance used alkali getter in CFB boilers.
Key words: Biomass combustion, Ash, Additives
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The effect of kaolin and peat ash on the combustion of demolition wood under
well controlled conditions
Roger A. Khalil 1,1 , Dusan Todorovic 2 , Øyvind Skreiberg 1 , Rainer Backman 1 ,
Franziska Goile 1 , Alexandra Skreiberg 1 and Lars Sørum 1
1) SINTEF Energy Research, NO-7465, Trondheim, Norway
2) University of Belgrade, 11000 Belgrade, Serbia
Abstract
In an attempt to look at means for corrosion reduction in boilers, combustion
experiments were performed on demolition wood with kaolin and peat ash as additive.
The fuel was reduced in size by grinding and mixed with kaolin prior to pelletization.
The combustion experiments were performed in a multi-fuel reactor with continuous
feed of the pellets by applying staged air combustion. In general a good control over
parameters that influence the combustion process in terms of fuel and air supply and
reactor temperature was obtained. In addition, the gas concentration and the particle
distribution in the flue gas was monitored. A total characterization of the elemental
composition of the fuel, the bottom ash and some particle size stages of fly ash was
also performed. This was done in order to follow the fate of some of the problematic
compounds in demolition wood as a function of kaolin and peat ash addition and other
combustion related parameters. In particular chlorine and potassium distribution
between the gas phase, the bottom ash and the fly ash is reported as a function of
increased additive addition, reactor temperature and air staging.
Kaolin addition of 5 and 10 % were found to give the least aerosol load in the fly
ash. In addition, the chlorine concentration in aerosol particles was at its lowest levels
for the same addition of kaolin, although the difference between 5 and 10 % addition
was minimal. The reactor temperature was found to have a minimal effect on both the
fly ash and bottom ash properties. Leaner oxygen conditions on the combustion grate
was also found to produce less particle load and aerosols with less chlorine content.
The results of adding 1-10 % peat ash to the demolition wood show that the
concentrations of zinc and lead are very high in the fly ash samples. A considerable
part of these metals are chemically bound to chlorides and sulfates together with
potassium and sodium indicating extensive volatilization of both zinc and lead.
Although it was not possible to determine quantitatively the effect of peat addition,
the experiments show that the reactions of potassium, zinc and lead are the metals
most affected. Thus, higher concentrations of zinc and lead are found in the aerosols.
Simultaneously the chloride content in the aerosols decreases with increased peat ash
addition. This will have an inhibiting effect on corrosion, but the higher Zn and Pb
concentrations may lead to lower melting points of the aerosol particles. This, again,
may promote deposition on heat transfer surfaces in the flue gas channel.
Keywords: Demolition wood, Combustion, Kaolin additive, Bottom ash, Fly ash,
Gas composition, ELPI, peat ash, lead, zinc
1 Corresponding author: roger.khalil@sintef.no
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POSTER PRESENTATIONS
Bioenergy
Renewable Energy Research Conference 2010 109

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THERMOCALORIMETRIC ANALYSIS OF FOREST WASTE
S. Pérez (perezrs@unican.es), C. J. Renedo (renedoc@unican.es), A. Ortiz
(ortizfa@unican.es), M. Mañana (mananam@unican.es), I. Fernandez
(fernandei@unican.es), F. Delgado (delgadof@unican.es)
Dept of Electrical and Energy Engineering, University of Cantabria
Av Los Castros s/n, 39005, Santander, Cantabria, Spain.
ABSTRACT
We have carried out the combustion simulation of a lignocellulosic material, obtaining the
maximum combustion temperature reached by varying the moisture and the excess of air.
Forest residues from several species have been characterized in a calorimeter: Eucalyptus
globulus, Fagus sylvatica, Quercus robur and Pinus radiata. In the laboratory, the forest waste
of each species was divided into fractions: leaves, thin branches (diameter

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ABSTRACTS
Renewable Energy in Transportation
Renewable Energy Research Conference 2010 111

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Biofuels Sustainable Production: Challenges and opportunities for
developing nations. Insight of the Colombian Case.
Carlos Ariel Ramírez Triana
Macquarie University: Macquarie Graduate School of Management (MGSM). Sydney,
Australia.
Politécnico Grancolombiano: Grupo de investigación en Desarrollo Sostenible (Research
group in Sustainable Development). Bogotá, Colombia.
Abstract:
caramirezt@hotmail.com carlosar@poligran.edu.co
In academic circles the convenience of using biomass as a source of energy has been
extensively discussed, but a final consensus seems far from being reached. This is essentially
due to the fact that bioenergy production comprises a complex set of variables if sustainable
goals are set, which implies that this source of energy must go beyond financial success,
hence it has to be environmentally friendly and socially responsible as well. Several sensible
arguments have emerged to exhibit disadvantages and benefits obtained from biodiesel or
bioethanol industry worldwide; however creating a final balance of biofuels production,
commercialization and use is out of the scope of this presentation.
The main objective of this particular work is to identify those variables mentioned above and
their interaction in terms of sustainability, and to establish their implications as potential
barriers or boosters for the industry in developing countries. A deeper exploration of the
nascent development of this industry in Colombia will be presented.
The presentation is limited broadly to developing nations within Latin-America and more
specifically to Colombia. The variable identification process will draw not only from a
comprehensive literature review of the strategies of multinational organizations involved in
this kind of bioenergy but also local, Latin-American and particularly Colombian
organizations. Required data to show feedstock and land availability will be obtained from
Statistic Division of Food and Agriculture Organization of the United Nations FAOSTAT.
In order to illustrate the impact on the biofuels implementation on the Latin-American region,
a map with the interconnected variables will be presented and an evaluation of the Strengths,
Weaknesses, Opportunities, and Threats will be made for the Colombian case.
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The standardization of major WTW databases:
Measuring uncertainty on a macro level
Hassan El-Houjeiri(hassan.el-houjeiri@eng.ox.ac.uk) and Robert Field,
University of Oxford, Department of Engineering Science, Parks Road, Oxford, UK
Due to concerns regarding Global Warming there has been increasing interest in Well-to-Wheel
(WTW) assessment of automotive fuels. Such analyses are increasingly required to assess the global
implications of prospective transport options for medium to long term futures. Whilst there have
been developments in the models of this type, including the integration of stochastic applications
which propagates the uncertainties inherent in the Life Cycle Inventory through to the model results,
there remains a number of shortcomings. These include significant discrepancies in the WTW results
between different models due inter alia to different methodological choices, system assumptions,
geographical distances, system boundaries and reference years of technology. Also no probabilistic
results that reflect these uncertainties are available today. The current project will provide a
statistically sound evaluation of the choices confronting decision makers in governments and the
automotive industry based upon a combination of major databases in the field including those from
the Institute of Applied Ecology (GEMIS) and the Joint Research Council, EUCAR and CONCAWE
(JEC).
In particular the aims of the present work are twofold. Firstly the information in the reference
databases was combined by reformulating it to evaluate energy loss and GHG emissions for the
different stages of the WTW chain. This has been done for over 48 different chains. These chains
include the exploitation of renewable resources and use in the transport sector through hydrogen in a
Fuel Cell Vehicle (FCV) and alternatively through electricity in a Battery Electric Vehicle (BEV).
Having reformulated the data into a common form by meticulous data work (restructuring, unit
conversions and aggregation) a portfolio was created for each building block of each chain. The
second part characterized the portfolios and employed Monte Carlo Simulation to propagate the
inherent variability throughout the full chain of fuel production and use. The resulting output
generates what we call “full-bodied” probabilistic results that represent the actual degree of
uncertainty combined from different well accepted models. The standardization1 process 1 smoothes
the output and generates reliable aggregates which are necessary for us to build long-term strategies.
The results also present a valuable “helicopter” overview from which to observe the extent to which
the different models agree and on the flip-side to point to the major sources of disagreement in the
energy debate.
The positioning of hydrogen, by some, as the best option to carry renewable energy into the transport
sector and the strong opposition of others has led us to test the hypothesis that the hydrogen
economy is not the transport solution for a GHG constraint world. It is important to assess not just
Well-to-Tank but the overall WTW. The presentation will be illustrated by results mainly from the
chains that are based on renewable resources (wind, hydro, solar, biomass, etc). The comparative
assessment will include all competing options and is based on full-bodied results which are
particularly valuable for studying subjects of strong disagreement.
1 Standardization in the context of our research refers to the process of developing WTW results that are agreed upon by those formulating the most acknowledged
models in the field.
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The achievement of sustainable mobility requires the co-existence of
numerous energy carriers
Geoffrey Gilpin 1 , Erling Holden 2
1 University of Life Sciences, department of mathematical sciences and technology & Western
Norwegian Research Institute – ggi@vestforsk.no
2 Sogn and Fjordane University College – erling.holden@vestforsk.no
Abstract:
Recent discussions concerning the decarbonisation of the transport sector facilitated by a
transition from fossil fuel based transport to a more environmentally benign form of
sustainable mobility tend to oversimplify the situation by suggesting a hierarchal evolution of
alternative transport fuels. This is highlighted by the linear segregation of biofuel research
and development into generations, now standing at current 1 st generation-, through to
proposed 4 th generation biofuels, and with the assumption that hydrogen and electric based
modes of transportation will eventually exclude, or greatly minimize, the need for other
alternatives in the future. This view of the evolution of future transport fuels is counterproductive
to the philosophy of industrial ecology, and its overlying goal of achieving
sustainability.
Through a review of relevant literature resources the field of industrial ecology and the
concept of sustainable mobility is discussed. The criteria by which the sustainability of
proposed alternative energy carriers is presented, and the application and validity of
developed life-cycle-assessment methodology is reviewed, and argued for as the best
available means by which to evaluate existing and proposed energy carriers.
A brief review is then presented for the potential of, and limiting factors to current and
proposed alternative transport fuels, and thereby clarifies the necessity of adopting a more
relaxed view towards the future of sustainable transport fuels. The term “fuel mosaic” is
introduced to describe this future scenario in which fossil fuels co-exist alongside hydrogen,
electricity, and biofuels as energy carriers. The variety of energy carriers is required by the
presence of varied transport applications, technologies, and their limited factors of production.
With this knowledge and the lack of realistic alternative technologies or modes of
transportation, and coupled with the expected increase in demand for these sectors, the
continued research, development and evaluation of biofuel is recommended.
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Second Generation Biofuels - a discussion on opportunities
and challenges related to processes and feedstocks
Børre Tore Børresen a (BTBO@Statoil.com),
Marianne Waage Fougner b (MWF@Statoil.com)
a Statoil ASA, Technology and New Energy, R&D
b Statoil ASA, Technology and New Energy, Bio Energy
There are national and international drivers in order to develop commercially successful
process routes for the production of biofuels from various sources. The aim of producing
biofuels from non-edible feedstock is primarily motivated by the large feedstock potential and
avoidance of ethical problems related to “food versus fuel”. The main reasons for such
processes not being in industrial operation today are certainly costs and availability of
affordable feedstock. The presentation will be used to discuss economical aspects of selected
biofuel production routs based on the various technological solutions related to paths
representing: biochemical, thermochemical and chemical processes.
Biomass/feedstock
A vital component in the biomass to fuel value chain is the access to economically affordable
biomass resources. The present cost of wood in Norway is in the range of 550-950 NOK/m 3
(incl. transport), which for a 100% conversion on energy basis yield a feedstock cost of 1,4-
2,4 kr/l. However, most processes today are in the range of 30-50% efficient, which will
result in a feedstock cost alone of about 3-5 NOK/l. Increasing the demand for this resource
will most likely drive the price for biomass upwards. Marine algae may represent an
alternative to lignocellulosic feedstock like wood, straw and energy crops like switch grass.
Biochemical/chemical routes
In the biochemical route the carbohydrates, extracted from the lignocellulosic materials, are
converted to alcohols by fermentation, primarily to ethanol but butanol may also be an
interesting option. Chemical conversion of carbohydrates, or hydrogenation of triglycerides,
could be alternatives to the biochemical or thermochemical routes.
Thermochemical routes
Biomass to liquids (BtL)
The classical thermochemical route is the conversion of the biomass to a syngas (CO/H 2 mix)
by gasification, and a subsequent chemical conversion of the syngas to liquid fuels using
chemical conversion technologies (Fischer-Tropsch synthesis and hydroisomerisation)
Pyrolysis
Pyrolysis is a thermochemical process for conversion of biomass to liquids by an anaerobic
thermal decomposition of the biomass to a bio-oil, which subsequently has to be upgraded in
order to achieve a useable fuel. Alternatively, pyrolysis may be used as pre-treatment stage
prior to biomass gasification.
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Short-term Global Warming Mitigation Costs of Fischer-
Tropsch Diesel Production and Policy Scenarios in Norway
Ryan M. Bright (ryan.m.bright@ntnu.no),
Anders Hammer Strømman (anders.hammer.stromman@ntnu.no)
Industrial Ecology Programme, Department of Energy and Process Engineering, NTNU,
Trondheim
Increasing the supply of advanced biofuels like synthetic diesel produced from woody biomass
require attractive investment environments so that novel technologies are deployed and
technological learning can lead to reduced production costs and accelerated market diffusion.
Technology-specific biofuel policy designed to minimize perceived risk may encourage shortterm
investment into those biofuels offering superior environmental benefits – particularly
climate mitigation benefits – thereby leading to steeper learning curves and deeper greenhouse
gas (GHG) emission cuts over the medium- and long-term horizon.
We perform both a Life Cycle Assessment (LCA) and an economic analysis of Fischer-Tropsch
diesel (FTD) produced from Norwegian forest biomass at an “n th ” commercial plant (a plant with
the same technologies that have been employed in previous commercial plants). This is followed
with a cost growth analysis in order to derive production costs likely to be borne by pioneer
commercial plants in Norway in the short-term (2016). LCA results are used to calculate shortterm
GHG mitigation costs. We then assess, through scenarios, how various policy measures and
financial support mechanisms would reduce production costs for incentivizing short-term
investment and expediting commercial deployment in Norway. Because “top-down” or “market
pull” biofuel support policy like excise tax exemptions or carbon taxes do not directly encourage
investment into specific biofuel technologies like wood-FTD in the short term, we choose to
analyze three “bottom-up” or “market push” policy scenarios to assess their effects on reducing
levelized unit production costs. These include a Capital Grant, a low-interest Loan Guarantee, a
Corporate Tax Credit, and a Feedstock Credit scenario. Under the Capital Grant scenario, we
assess the change in levelized production and thus GHG abatement costs when a 50% capital
grant (TCI) is provided to pioneer investors. Under the Loan Guarantee scenario, we assess the
cost implications of 100% direct government financing at 2% interest. Under the Corporate Tax
Credit scenario, we assess cost changes related to a 100% corporate tax credit, or a 0% income
tax rate; and under the Feedstock Credit scenario, we assess cost changes related to a $30/tonne
subsidy on intermediate feedstock inputs over the life of the analysis period.
When comparing results to the ex-tax price (+ CO 2 tax) of conventional diesel under a medium
oil price scenario ($105/bbl, $0.98/liter diesel), we find that all but the Loan Guarantee policy
alternatives lead to GHG mitigation costs of under $22/tonne-CO2-eq.-avoided (NPV). From an
investor standpoint, we find that investor profitability is maximized through the provisioning of a
matching Capital Grant, and because the present value of this government policy alternative is
most cost-effective in terms of reducing transport GHG emissions while offering additional
benefits of being time-bound and budget-limited, we argue for Norway that such a policy would
be favorable over the other support policies considered.
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HowDoWeManageOurLimitedBioCarbonResourcesBest?
Canwejustburnbiomassinthefuture?
PetterHieronymusHeyerdahl,AssociateProfessor,UniversityofLifeSciences,Norway.
Petter.heyerdahl@umb.no
ÅS,UMB,20100225
Therearetwogoodreasonswhyfossilfuelpriceswillriseinthefuture.Firstly,inthenear
futureoilwillbeshort.Secondly,weneedtolimitourCO 2 emissions.Apowerfultooltoobtain
reductionsisbyCO 2 tax.Toobtainsubstantialreductionsthetaxesneedtoberatherheavy.
Intheforeseeablefuture,biofuelsandelectricityseemtobetheonlyrelevantalternative
transportationfuels.Electricityisnotusefulinaircraftsandshipswhichconsumemorethan1/3
oftheliquidfuelsinNorway.Allautomakerswillpresentelectricorpluginhybridelectric
vehicleswithinthenextfewyears.However,massiveintroductionofEVsandPHEVswilltake
manyyears.Hence,liquidfuelswillbethedominatingtransportationfuelforalongtime.
Duringthenextdecadewecanexpectproductionofbiofuelsfromwoodandbiomass,so
called2 nd generationfuels,tobeindustrialized.Thetotalconsumptionofliquidfossilfuelsfor
transportationinNorwayisabout7.5billionlitersperyear.Ifthisistobereplacedby2 nd
generationfuels,roughly75millioncubicmetersofwoodorbiomassequivalentsisneeded
yearly.
TheNorwegiangovernmenthastargetedtoreplace14TWhofelectricityandoilbasedheating
inboilerswithbioenergy.About7millionadditionalcubicmetersofbiomassisneededyearly
tomeetthisdemand.
ThesustainablebalanceproductionofwoodfromNorwegianforestsmaybemorethan25
millioncubicmetersayear.Today,thefellingisabout10millioncubicmeters.Ifthebiofuel
andheatmarketsarefullyopened,thebiomassdemandmaybemanytimesgreaterthanwhat
isavailablefromNorwegianforests.
Thepriceelasticityfortransportationfuelsislow.Asthetransportationfuelspricesrise,bio
fuelswillbemoreprofitabletomake.Thiswillpullbiomassoutoftheleastprofitablemarkets.
Biomassboilersmaybeamongthefirstvictims.
Themostvaluablepartsofadistrictheatingsystemaretheinfrastructureandthecustomers.
Asthevalueofwood,ormorepreciselybiologicalcarbon,rises,weneedtofindanotherheat
source.AstableandunlimitedheatsourceisDeepGeothermalEnergy,DGE.Wecandrillabout
5000meterdeepholesunderthebiomassboiler,circulatewaterintheholesandfeedthe
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districtheatingsystemwithgeothermalenergy.Ifthewatertemperatureishighenough,the
plantcanevengeneratesomeelectricity.Thefuelisfree,available24/7andwilllastforever.
Properlydesignedtheplantswillhaveminornegativeenvironmentalimpact.Themost
importantbarriertoutilizethisresourceisthepriceoftheholes.
Weknowfossilfuelpriceswillrise,weknowthedemandforliquidfuelsfortransportationwill
behighforyears,weknowthewillingnesstopayfortransportationfuelsishigh,weknow
factoriesfor2 nd generationbiofuelswillcomeandweknowtherewillbeanincreasedpressure
onbiologicalcarbon.Hence,burningbiomassforjustmakingheatwillhardlybeviableinthe
future.Thefireplaceandprivatemarketswillofcoursesustain.
Norwayhasdevelopedworldclassexpertiseondeepwelldrillingoffshoreandinvestigating
techniquesforgeologicalformations.Weshouldnowinvitethisexpertiseonshore,mixitwith
companiesandscientificenvironmentsworkingondrillingtechnologiesandestablishascience
centerforenvironmentalfriendlyenergy,FME,tomakehightemperaturegeologicalheat
competitive.ThiscouldopenaworldmarketforNorwegianrenewableenergytechnology
basedonknowledgeandmoneyfromouroilindustry.
Yearly,theNorwegiangovernmentputsbillonsofkronertosubsidizeinfrastructurefordistrict
heatingsystemsandboilersforbiomasscombustion.Despiteheavysubsidiestheprofitabilityis
low.Evenminorincreasesinbiomasspriceswillcauseproblems.However,lotsofbuildingsin
Norwayconsumelargeamountofheat.Decadeswillpassuntilnewstandardsforenergy
efficiencyachieveappreciableimpacttoreduceneedforexternalheatsupply.Hence,the
NorwegiangovernmentandENOVAshouldcontinuesubsidizinginfrastructurefordistrict
heating.Besidesreleasingelectricity,thiswillcontributetoestablishstableandprofitablevalue
chainsforbiomassfromhabitattoboilers.Inthiswaywewillbewellpreparedtoswitch
feedstocksupplyfromboilerstothe2 nd generationbiofuelplants.Simultaneously,bigmarkets
forDGEwillbeready;thepipeswillalreadybethere.
phh
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Environmental and economic feasibility of sugar cane ethanol
in the Mexican transportation sector
Carlos A. García a (cagab@cie.unam.mx),
Fabio Manzini b (fmp@cie.unam.mx)
a Posgrado en Ingeniería (Energía), Centro de Investigación en Energía, Universidad
Nacional Autónoma de México, Privada Xochicalco S/N, Colonia Centro, Temixco,
Morelos, 62580, Mexico.
b Centro de Investigación en Energía, Universidad Nacional Autónoma de Mexico,
Privada Xochicalco S/N, Colonia Centro, Temixco, Morelos, 62580, Mexico.
ABSTRACT
This study analyses the environmental and economic feasibility to produce sugar cane
ethanol to substitute gasoline from 2010 to 2030 in the Mexican transportation sector.
One scenario was created by projecting energy demand and assuming that a fraction of
this demand is satisfied with ethanol produced from the cultivation of 2.9 million hectares
of sugar cane, based on a potential study calculated by other authors. The environmental
section considers the Green House Gases (GHG) emission in the life cycle, and water
consumption. The life cycle GHG emissions were calculated according to the
recommendations from the European Union Directive on Renewable Energies (that
include direct Land Use Change emissions), and the water consumption was calculated as
the Water Footprint. In the economic section, ethanol’s production cost is calculated, and
a mitigation cost of Carbon Dioxide is estimated. The results show GHG mitigation, a
very high water use and an ethanol’s production cost similar to the corn ethanol in the
US.
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As Cast and Rapidly Solidified Ti-V Alloys for Hydrogen Storage
Suwarno Suwarno a (suwarno@material.ntnu.no ), Yoan Gosselin b ,
Jan Ketil Solberg a , Jan Peter Maehlen b , Volodymyr A. Yartys a,b
a Department of Materials Science and Engineering, NTNU, 7491, Trondheim, Norway
b Institute for Energy Technology, P.O. Box 40, 2027, Kjeller, Norway
Hydrogen storage materials play an important role in accumulation of energy produced
by renewable resources. Ti, V and their alloys are able to absorb and store hydrogen with
high gravimetric (3.78-4.01 wt. % H) and volumetric (up to 150 kg/m 3 ) efficiencies. Such
volumetric density of H has a record value for the metal hydrides and is more than two
times higher compared to LH 2 . Ti-V-based hydrides are prospective materials for use at
medium / high temperatures, for example, in heat storage. The goal of this work was in
optimisation of their hydrogen sorption properties; the operating temperatures were
chosen between 500 and 800°C. Alloys of Ti 1-x V x with x=0.1-0.4 were synthesized by
argon arc melting. SR-XRD was used to study the alloy and hydride structures. The
alloys were found to crystallise with the BCC structures; a gradual decrease of the unit
cell parameters was observed following an increase of the V content. The microstructure
of the Ti 0.8 V 0.2 alloy was modified by performing a rapid solidification process using a
melt spinner with a wheel rotation speed of 1000 and 3000 rpm. The hydrogenation
properties were studied using the TDS technique. Microstructural characteristics were
examined using LOM, SEM and EPMA. Vanadium destabilises the formed hydrides of
the Ti 1-x V x alloys, and a gradual significant decrease of hydrogen desorption temperatures
took place from 458°C (10 at.%V) to 320°C (40 at.%V). Despite vanadium slightly
decreases the maximum hydrogen sorption capacity, yet these alloys are able to absorb
minimum 3.9 wt.% H. Microstructures of the rapidly solidified at 1000 rpm spinner
rotation speed alloys are composed of fine grains with average size of 20 m, as it is
shown in the Figure. Increase of spinner speed decreases the grain size. Grain refinement
resulted in improved hydrogen absorption and desorption kinetics. Hydride of rapidly
solidified at 3000 rpm Ti 0.8 V 0.2 has a decreased thermal stability (peak of H desorption is
located 70 °C below that for the as cast alloy). The alloy activation was also found to be
easier for the RS alloys. In summary, the melt spinning process yields improvement of
the hydrogen storage behaviours of the Ti-V alloys and can be used for their optimisation.
500 m
25 m
(a)
(b)
Figure. Microstructures of (a) Arc melted Ti 0.8 V 0.2 , (b) Melt spun Ti 0.8 V 0.2 (1000 rpm spinner
speed). A significant grain refinement is observed during the RS.
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Characterization of core-shell catalyst for
electrooxidation of small organic molecules
Piotr Ochal 1 , Jose L. Gomez de la Fuente 1 , Mikhail
Tsypkin 1 , Frode Seland 1 , Selim Alayoglu 2 , Bryan
Eichhorn 2 and Svein Sunde 1
1
Department of Materials Science and Engineering,
Norwegian University of Science and Technology
(NTNU)
Sem Sælands vei 12, NO-7491, Trondheim, Norway
2
Department of Chemistry and Biochemistry, University
of Maryland
College Park, MD 20742, Maryland, USA
ochal@material.ntnu.no
Introduction Core-shell structured catalysts have
received much attention due to their particular
properties. [1] A combination of
several physicochemical
techniques such as STEM,
XPS, EXAFS or HAADF is
necessary for verification of
the core-shell structure. [2,3] In
this study CO stripping
voltammetry was adapted, as
an electrochemical tool for the
evaluation of a Pt shell at Ru core
(Ru@Pt) electrocatalysts.
Experimental The Ru@Pt (with several ratios) core-shell
nanoparticles were synthesized using a sequential polyol
process. The reference Ru sample was formed by a hot
reduction of the salt precursor in ethylene glycol, using
poly(vinylpyrrolidone) (PVP) as a stabilizing agent. The
reference Pt was prepared in a similar way. Nanoparticles
were deposited on carbon under sonication, then washed
and centrifuged. Potentials were measured vs. RHE.
Results and Discussion The images below show a
Pt@Ru particle characterized by TEM and STEM.
Ru@Pt (1:1) TEM
Line scan intensities reflect monomodal and bimodal
shapes for Ru and Pt, respectively, indicating a core-shell
structure.
Ru@Pt (1:1) STEM
CO stripping voltammograms (adsorption at 50 mV) of
Pt/C, Ru/C references and Ru@Pt/C 1:1 and 1:2.5
catalysts are presented in the right column. An
electrochemical passivation of Ru takes place within the
0.30
0.15
I / mA
0.00
0.08
I / mA
0.00
-0.08
CO stripping
CO stripping post-oxidation
Pt / C
0.0 0.2 0.4 0.6 0.8 1.0
E / V vs. RHE
CO stripping
CO stripping post-oxidation
0.0 0.2 0.4 0.6 0.8 1.0
E / V vs. RHE
Ru:Pt 1:1
0.30
0.15
I / mA
0.00
-0.15
-0.15
CO stripping
CO stripping post-oxidation
Ru / C
0.0 0.2 0.4 0.6 0.8 1.0
E / V vs. RHE
0.0 0.2 0.4 0.6 0.8 1.0
CO stripping from Pt and Ru references and
core-shell Ru@Pt (1:1 and 1:2.5)
0.15
I / mA
0.00
CO stripping
E / V vs. RHE
Ru:Pt 1:2.5
potentials range of 1.1

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Hydrogenation behaviour and crystal structure of the LaMg 11
with a giant unit cell synthesized by hydrogen metallurgy
Andrey Poletaev a,b , Roman Denys b,c , Jan Ketil Solberg a ,
Volodymyr Yartys a,b
a Norwegian University of Science and Technology, Trondheim, Norway
b Institute for Energy Technology, Kjeller, Norway
c
Physico-Mechanical Institute / National Academy of Sciences of Ukraine, Lviv, Ukraine
Applications of magnesium hydride as a hydrogen storage material suffer from the poor
hydrogenation kinetics of the magnesium metal. A significant improvement in the rates
of hydrogen exchange can be achieved by nanostructuring of the Mg-based alloys. In the
present work, a LaMg 12-x intermetallic compound was synthesised by completing a
hydrogen absorption-desorption cycle by a 1:12 mixture of elemental metals, La and Mg.
A reactive ball milling (RBM) in hydrogen gas was followed by a vacuum thermal
desorption. Hydrogen desorption from the LaH 3 + 12 MgH 2 nanocomposite occurred at
rather low temperatures, below 450 o C. Complete hydrogenation took place during a 2 h
milling at 30 bar H 2 ; RBM resulted in the formation of the crystallites of binary hydrides
with sizes below 10 nm. The detailed mechanism of the transformation of the LaH 3 -
MgH 2 hydride composite into intermetallic compound during the hydrogen vacuum
desorption was studied by in situ SR XRD. Several transformation steps of the metalhydrogen
interaction were identified:
(a) -MgH 2 -MgH 2 ; (b) -MgH 2 Mg;
(c) -MgH 2 Mg; (d) LaH 3 LaH 2 ;
(e) LaH 2 +Mg LaMg 10.85.
The crystal structure of the synthesized
by hydrogen metallurgy LaMg 10.85
was determined from an SR XRD
Rietveld profile refinement. Is has a giant
orthorhombic unit cell with a volume exceeding 8000 Å 3 (sp. gr. Immm; a = 10.3391(5),
b = 10.3554(5), c = 77.484(4) Å). A substitution of La by Mg 2 dumbbells was observed.
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The Renewable Energy Research Conference Abstract
A useful tool in energy efficient reactor design evaluated for the
Gas Heated Reformer: the specified entropy production
Øivind Wilhelmsen a, c (oivind.Wilhelmsen@sintef.no),
Margrete H. Wesenberg b (margh@statoil.com),
Signe Kjelstrup a (signe.kjelstrup@chem.ntnu.no)
a Department of Chemistry, Norwegian University of Science and Technology
b Department of Chemical Engineering,, Norwegian University of Science and Technology
c SINTEF Energy Research
The second law efficiency, II , can well be used to investigate the energy efficiency of
chemical reactors, where a reversible reactor represents an efficiency of 100%, and the
Gouy-Stodola theorem gives the source of the irreversibilities, i.e. the relation between
the entropy production and the lost exergy or lost work [1] . We show how the specified
entropy production can be used as a tool to compare the energy efficiency of chemical
reactors, and show that the specified entropy production provides a good understanding
of the efficiency. The specified entropy production is defined as the ratio of the total
entropy production and the amount of chemicals produced. We show how it applies using
the design of a Gas Heated Reformer (GHR) as example. The GHR is used to produce
hydrogen, and the project is thus relevant to studies of hydrogen as an energy carrier. The
objective of the work is to present a simple tool that can be used to compare different
reactor designs with respect to the energy efficiency.
The reformer is a chemical reactor which produces hydrogen from steam and natural gas.
The GHR is a reformer design in which the heating medium is a hot gas flowing in a
concentric shell around the reformer tube [2] . We have solved the balance equations for
a pseudo homogeneous one-dimensional model of a GHR which includes diffusion in the
catalyst pellets accounted for by non-constant effectiveness factors, and convection as
well as radiation in the annular heating section. A reference case has been established.
Different reactor designs have been compared to the reference case on the basis of the
specified entropy production, with respect to changes in the reactor length, the hydraulic
diameter and the size of the catalyst pellets. The reactor model was created in Matlab [3].
Figure 1 – Variation in the specified entropy production, S spec, with catalyst diameter, D p .
Figure 1 shows how the specified entropy production changes with the size of the catalyst
pellets. The figure shows that from an energy efficient point of view, there is no point of
using larger pellet-diameters than 1.6 ± 0.1 cm with a 9 cm diameter reformer tube.
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References
[1] Bejan A. Entropy generation through fluid flow. 1994.
[2] Wesenberg M.H. Gas Heated Steam Reformer Modelling. PhD Thesis, The
Norwegian University of Science and Technology, 2006.
[3] Wilhelmsen Ø. The state of minimum entropy production in reactor design. M Sc
Thesis, The Norwegian University of Science and Technology, 2010.
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ON-SITE HYDROGEN PRODUCTION – AN IEA-HIA TASK
Ingrid Schjølberg a (Ingrid.Schjolberg@sintef.no)
a SINTEF ICT, Applied Cybernetics
N-7465 Trondheim
Objective
On-site hydrogen production is an important stepping stone towards the development of a
hydrogen infrastructure and a more environmental friendly transport sector. Currently,
on-site production units can be developed in any required size. It is important for vendors
that norms for size, footprint and capacity exist and that the boundary conditions are
given so that focus can be on the technology development. Harmonization of the
technology is essential to enable mass production. This can be done in several ways,
however, a cooperation across industry’s and research disciplines is required. Task 23 is
an international collaboration project, under the International Energy Agency Hydrogen
Implementing Agreement (IEA-HIA), focusing on on-site hydrogen production from
natural gas. Nine countries are represented in the project, Norway, Sweden, Denmark,
Japan, US, Netherlands, Turkey, France and Germany. Task 23 is addressing: i)Safe and
harmonized technology for on-site production, integration of reformer and carbon capture
unit and the implications for carbon capture technology ii)Generation of
recommendations for accelerated market deployment of renewable energy technologies,
identification of technical, regulatory, and other market factors that affect market
deployment of renewable energy technologies iii) Barriers, both technical and nontechnical,
to the introduction of hydrogen are being reduced through advances in
renewable energy technologies and hydrogen systems including progress in addressing
hydrogen safety codes & standards.
Methodology
The methodology is based on analysis of results from demonstration projects world wide,
statistics and new research.
Results
The developed global market guide will contribute to the market development by
spreading awareness on possibilities in the technology development of on-site hydrogen
production units. This is seen in the development of hydrogen infrastructure in Europe,
US (California) and in Japan which all have included service stations with on-site
production. Cost comparison on different technologies for Europe, US and Japan are
given. The figures indicate that in an early market phase, for instance, on-site reforming
is cheaper than centralized production. This confirms the need for a harmonization of
technology as in footprint, capacity and size to reduce costs and enable mass production.
Japanese numbers have been included in an extended study and the same results are
achieved. Various fuel paths have been developed also including CCS technology.
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Hydrogen in Marine Diesel Engines
Arne Vöglera (arne.vogler@lews.uhi.ac.uk)
University of the Highlands and Islands (UHIMI) / University of Aberdeen
To investigate ways of reducing the yearly fuel oil consumption of the UK fishing fleet
of 300 million liters, with associated carbon emissions of 802,500tonnes,
experiments were undertaken to explore the feasibility of supplementing diesel fuel
in compression ignition engines with both on board generated oxy hydrogen and
bottled hydrogen.
A Beta Marine BD722 3 cylinder engine fitted on board of a 9.4m vessel was used
as a test bed and parameters monitored included the in cylinder pressure, fuel
economy (tank to propeller thrust analysis), exhaust gas analysis and the thermal
performance at various load conditions.
The outlet of an oxy hydrogen electrolyzer was connected to the air intake of the
engine and the performance was monitored by powering the unit directly from the
engine’s alternator and also by an external battery. Another approach used bottled
hydrogen gas which was introduced into the air intake at varying rates between 5%-
20% of the overall energy supplied and measured values were compared with
baseline data gathered during diesel fuel only operations.
Figure 1 - In cylinder pressure during power stroke
By examining the force applied to a mooring rope under static conditions the
propeller thrust of the vessel underway was calculated for varying speeds and the
mechanical engine efficiency for different fuel ratios and loads was determined.
Results have confirmed that modest fuel savings can be achieved by supplying
hydrogen into the air intake of a diesel engine. The occurrence of engine knock at
higher hydrogen supply rates was observed and it is indicated that this could be
counter acted upon by shifting the injection timing closer towards top dead centre.
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From wood to biofuels and chemicals – challenges and solutions in pretreatment of lignocellulosics.
Karin Øyaas and Kai Toven, Paper and Fibre Research Institute (PFI AS), Høgskoleringen 6B, NO-7491 Trondheim, Norway.
(Karin.oyaas@pfi.no)
The utilisation of Nordic wood resources is vital for the expansion of a Nordic biofuels industry.
Substitution of gasoline with fuel-ethanol from lignocelluloses is estimated to reduce CO 2 emissions
in the transport sector by up to 90% (IEA, 2004).
A major barrier for the deployment of wood-based biofuels is its high production cost. In particular,
the pre-treatment step represents one of the most expensive processing steps in the conversion of
cellulosic biomass to fermentable sugars. The physical barriers of the plant cell wall as well as low
water solubility and crystalline nature of cellulose represent central challenges. Furthermore,
different biomass raw material inputs and different conversion routes set different requirements on
the pre-treatment processes. Thus, the wood pre-treatment step, preceding hydrolysis and
fermentation, has a great potential for improvement through innovative research and development.
Pre-treatment covers both mechanical, chemical, thermal and biochemical processes and represents
the central starting point in the processing of biomass to biofuels and chemicals. In general, the pretreatment
process should maximize the yield of fermentable sugars and minimize the formation of
compounds that inhibit subsequent process steps (e.g. enzymatic hydrolysis, fermentation). Nonfermentable
biopolymers should be separated for further conversion into value added by-products.
Lignin removal is favourable as the accessibility of hydrolytic enzymes is improved.
In this presentation, different wood pre-treatment strategies, aiming at effective biomass
fragmentation and delignification and low formation of undesirable carbohydrate degradation
products will be discussed.
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Kinetic study of the esterification of free fatty acid and ethanol in
the presence of triglycerides using solid resins as catalyst.
J.M. Marchetti 1
+ Chemical Engineering Department. Faculty of Natural Science and Technology.
Sem Sælands v.4 NO-7491. Trondheim. Norway
Abstract
Biodiesel production is gaining more and more relevance due to its environmental
advantages as well as because of the petroleum world situation: decreases of the reserves,
augmentation of the prices, etc.
The kinetics of the esterification of free fatty acid (oleic acid in this case) in the
presence of triglycerides and ethanol was obtained when a solid resin was employed.
Using the controlling step method, several kinetic expressions have been developed and tested
against the experimental data. This was done employing a non linear multi parametric routine.
The kinetics expression obtained represented satisfactorily the experimental
information for several operations conditions.
Keywords: biodiesel, esterification, kinetic, sulfuric acid, acid oil.
1
Corresponding author: jorge.marchetti@chemeng.ntnu.no
Tel: +47-73594598
Fax: +47-73594080
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Hydrocracking of Rapeseed oil
Shanmugam Palanisamya (shapal@chalmers.se),
Börje S. Geverta (gevert@chalmers.se)
aChalmers University of Technology, Sweden
Vegetable oil to diesel is more attractive due to capable in production through
agricultural source. Particularly, hydro processing of vegetable oil on NiMo-S/Al2O3
ability to reduce sulphur content but still competent in gaining full efficiency on
desired product by domination of decarboxylation and decarbonylation [2,3].
The experimental set-up consists of a feed tank, fixed-bed reactor, product tank,
gas collector and Dossier pump. The analysis is performed using a gas chromatograph
(GC) technique (Varian 3400) equipped with a packed column and flame ionization
detector (FID). The outlet gas from the reactor is analysed using the Clarus 500 GC.
The thermal decomposition in rapeseed oil is estimated with different thermal
condition and with or without hydrogen at 1 bar partial pressure between 300 to
410 o C.
Initially, the reactor is loaded with glass pellets, and rapeseed oil fed in it. During
hydrothermal condition around 300 to 410oC on rapeseed oil, there are major interior
structure modification, with which 40% of decomposed product were observed. The
formation of oxygenate group, i.e. glycerol, acids and aldehydes, had 25 to 50% hare,
and rest contains thermally cracked hydrocarbons. The major glycerol structure
modification is shift in position of unsaturated bonding between carbonium groups.
Also, cyclic group formation is observed. The presence of acidic and aldehyde group
dominates the major cracked product by releasing carbon dioxide and carbon
monoxide in outlet gases. To conclude, the hydrogenation of rapeseed oil on medium
temperature without any catalyst gives lighter cracking and leads to aromatic group
formation with longer residance time. From the result, and -carbon breakage is
evidence during thermal decomposition without any effect by hydrogen partial
pressure. CO formation results in decarbonylation is dominant than decarboxylation
during thermal cracking.
Referance
1. Antoine Osmont, Mohammed
Yahyaoui, Laurent Catoire,
Iskender Gökalp, Mark T.Swihart,
Comb. and Flame, 155, 2008, 334-
atalysis
lyst A:
Gen. 199 (2000) 147–190.
2. J.Gusmao, D.Brodzki, G.Djega-
Mariadassou and R.Frety, C
Today, 5, 1989, 533 - 544.
3. E. Furimsky, Applied Catalyst A.
Gen. 199 (2000) 147–190
Figure 1 – Liquid sample analysed at gas chromatography
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Modeling of Single Tube Fischer-Tropsch Reactor for Model
Biosyngas
Muhammad Hamid Rafiq (mhamid.rafiq@ntnu.no),
Johan Einar Hustad (epost@epost.ivt.ntnu.no)
Department of Energy and Process Engineering, Norwegian University of Science and Technology
Department of Energy and Process Engineering, Norwegian University of Science and Technology
Fischer-Tropsch Synthesis is an important chemical process for the production of liquid
fuels. The present study addresses the modeling of low temperature single tube Fischer-
Tropsch reactor for a model biosyngas (33%H2, 17%CO and 50%N2). Cobalt based
catalyst is used for synthesis due to its high activity and selectivity for linear
hydrocarbons and lower price compared with other noble metals.
The chemistry taking place in a FT reactor is complex but can be simplified by the
following reaction
(1)
For cobalt catalyst methanation reaction and shift reaction is neglected.
Yates and Satterfield[1] determined the intrinsic rate constant of H2 consumption on a
commercial cobalt catalyst. According to Steynberg et al.[2], the intrinsic activity of
modern industrial cobalt catalyst is by a factor of three times higher then those reported
by the abovementioned author. So, the equation of hydrogen consumption on a
commercial cobalt catalyst is estimated (using the threefold value) and is given below:
Modeling of Single tube fixed bed Fischer-Tropsch reactor is done with one or two
dimensional pseudo homogeneous model.
Among many thing the influence of cooling temperature effects are studied on the axial
molar composition profiles, molar flow of reactant and product and reactant conversion.
In addition effect of cooling temperature on the axial temperature profiles in a single tube
Fischer-Tropsch reactor is also studied.
1. I.C. Yates, C.N. Satterfield, Energy and Fuels 1991, 5, 158.
2. A. Steynberg, M. Dry, M.E. Davis, B.B. Breman, in Fischer-Tropsch Technology,
Studies in Surface Science and Catalysis 152, (Eds: A. Steynberg, M. Dry),
Elsevier, Amsterdam 2004.
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Catalytic steam reforming for the production of biomass
derived synthesis gas
Espen S. Wangen (wangen@chemeng.ntnu.no),
Amin Osatiashtiani (osatiash@stud.ntnu.no),
Edd A. Blekkan (blekkan@chemeng.ntnu.no)
Norwegian University of Science and Technology
Objective
Synthesis gas (syngas), a mixture of H2 and CO, is an intermediate in the
production of several fuels and chemicals. The syngas may be produced from fossil
resources like natural gas and coal. However, the concerns associated with the increase in
atmospheric CO2 concentration make biomass a possible source in the future. Syngas
from biomass can be produced by gasification, followed by multiple physical and
chemical cleaning steps. This gas conditioning is necessary due to the wide range of
contaminants present in the raw product gas.
The product gas from a biomass gasifier will also contain unconverted
hydrocarbons that should be converted in order to maximise the syngas yield. The focus
of this project was the conversion of such hydrocarbons by catalytic steam reforming.
Conventional nickel catalysts are widely used in steam reforming processes. However,
these materials are rapidly deactivated by sulphur compounds. In this project, three novel,
monolithic non-nickel catalysts were compared and investigated in terms of steam
reforming activity and stability.
Methodology
Steam reforming reactions were carried out in a tubular steel reactor with three
different monolithic catalysts (ceramic, 400 cpsi). The reactant gas in these experiments
was a model gas whose composition was as follows: CH4: 12 v-%, C2H4: 5 v-%, CO: 23
v-%, CO2: 25 v-%, H2: 35 v-%. N2 was added as internal standard. Water was fed by a
liquid pump. The composition of the product gas from the steam reforming was analysed
by means of a micro-GC.
Reactions were carried out at temperatures from 620 to 720 °C and atmospheric
pressure. The steam:carbonorganic ratio in the experiments was between 3 and 10. In order
to investigate the effect of tars (defined as aromatic hydrocarbons higher that benzene)
toluene (light tar) and 2-naphthol (heavy tar) was added as model tar compounds in some
of the experiments.
Outline of results
The catalysts proved to be active at the chosen conditions. CH4 is the more stable
component in the system, and close-to-equilibrium conversion was achieved. As for the
higher hydrocarbons, full conversion was achieved. The results indicate that no catalyst
deactivation occurred during the first hours of operation. However, carbonaceous
material was observed by visual inspection of the monolith after reactions.
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Economic Modeling of Bio-SNG concepts
Dipl. Wi.-Ing. Lars-Peter Lauvena (lars.lauven@wiwi.uni-goettingen.de);
Prof. Dr. Jutta Geldermanna (geldermann@wiwi.uni-goettingen.de)
Georg-August-Universität Göttingen, Chair of Production and Logistics, Platz der Göttinger Sieben 3, D-37073
Göttingen, Germany, +49(0)551/39-7783, lars.lauven@wiwi.uni-goettingen.de, http://www.produktion.unigoettingen.de
Production of hydrocarbons via Fischer-Tropsch synthesis is one of the core technologies for the
production of second-generation biofuels. While methane is among the least valuable products of
Fischer-Tropsch reactors, it is the only one that can be produced with a carbon selectivity of
close to 100 %. Accordingly, much less separation and upgrading equipment is necessary to
produce a marketable product. Consequently, lower capital expenditure helps to compensate for
the lower product price.
The German research institutes ZSW and Fraunhofer IWES propose a concept that uses biogas
(CH4/CO2) and hydrogen instead of synthesis gas as feed for the synthesis reactor. CO2 and
hydrogen can then react in a methanation reaction, increasing the CH4-share, as well as the
carbon efficiency of the biomethane concept as a whole, from 50-60 % to close to 100 %.
The decisive question is whether such an arrangement will be economically feasible. Hydrogen
can be supplied using an electrolysis unit, while a Fischer-Tropsch reactor with a nickel catalyst
is well suited for the methanation reaction. Compared to existing biomethane facilities, these two
processes would have to be added, while CO2-removal units would no longer be necessary. In
order to run the electrolysis unit, significant amounts of electricity are necessary which could e.g.
be bought at the European Energy Exchange (EEX). As electricity is significantly cheaper at
night, running the electrolysis e.g. from 11 pm to 8 am may improve the economics of the
process significantly. From a LCA perspective, using electricity bought at the EEX will however
mean including fossil and nuclear resources for the production process, which may be an
obstacle for legal recognition as a biofuel. In the future, an expanding electricity production from
offshore wind farms may improve both the economic prospects of the concept due to increased
electricity supply at night (i.e. cheaper prices) and the carbon footprint via a higher share of
renewable in the electricity mix.
The economics of these processes, however, are very sensitive to capital expenditure and input
factor costs. To model the effects of varying prices for equipment, fossil fuels, biomass and
electricity, a mixed-integer linear programming (MILP) has been set up to help determine
whether the discussed combination of biogas, Fischer-Tropsch and electrolysis may become a
viable method to store energy from fluctuating sources such as wind power and increase the
output of biofuels from a given amount of biomass.
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Compact Conversion of Natural Gas and Biomass to DME in
Microstructured Reactors
Rune Myrstada (rune.myrstad@sintef.no)
aSINTEF Materials and Chemistry, NO-7465 Trondheim, Norway
Efficient production of easily distributable fuel from natural gas or biomass in the small-to-medium
scale calls for a more compact and efficient process than using conventional technology.
Microstructured reactors have improved heat and mass transfer properties which make them suitable
for process intensified production of liquid fuel from synthesis gas and demonstration plants using
such technology are announced.
Dimethyl ether (DME) can be used as an intermediate in the production of several industrial
chemicals and DME is also used as an aerosol propellant because of its environmentally benign
properties. Since DME has high cetane number and is considered as an ultra-clean fuel with reduced
NOx, SOx, and PM emissions, DME has emerged as a substitute for auto diesel fuel and bio-DME is
one of the most promising second-generation biofuels. DME can be prepared in a one-step process
from synthesis gas, which is thermodynamically and economically favourable to the two step process
consisting of methanol synthesis followed by dehydration of methanol to DME. As the direct process
is strongly exothermic, the reaction heat has to be effectively removed from the reaction system in
order to maintain a safe and economic operational mode. Direct DME synthesis possesses a high
volumetric heat production rate and hence the temperature control is a main challenge. Besides this,
parameters such as syngas composition, pressure, contact time and catalytic system affect the
conversion and yield.
In this work direct DME synthesis from syngas in a microstructured packed bed reactor was
demonstrated to operate at practically isothermal conditions (Figure 1). The performance of the
catalyst was enhanced by elimination of the undesired phenomena related to the exothermic process,
such as hot spot formation and side reactions. The influence of process parameters on methanol
selectivity and DME productivity was studied. The highest CO conversion was achieved by a H2-rich
syngas at high temperature and high pressure. However, experiments and simulations show that the
highest DME yield was obtained for a feed containing a H2/CO ratio close to 2. While the selectivity
to methanol increases with H2 concentration, DME is limited due to excess water via the water gas
shift reaction.
Figure 1- Simulated temperature profile in the microstructured reactor.
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From oil refinery to biorefinery: LCA of a wood-based concept
co-producing transportation biofuels, bioenergy and chemicals
Francesco Cherubini (francesco.cherubini@ntnu.no),
Ottar Michelsen
Anders Hammer Strømman
Department of Energy and Process Engineering, Norwegian University of Science and
Technology (NTNU), NO-7491 Trondheim, Norway
Our strong dependence on fossil fuels results from the intensive use and consumption of
fossil energy which, combined with diminishing fossil resources, causes environmental
and political concerns. There is clear scientific evidence that emissions of greenhouse
gases (GHG), such as carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O),
arising from fossil fuel combustion and land-use change as a result of human activities,
are perturbing the Earth’s climate. A possible mitigation strategy to this effect is the
replacement of oil with biomass as raw material for both energy and chemical production.
Similarly to what occurs in oil refinery, in biorefinery complexes almost all the types of
biomass feedstock can be converted to different classes of biofuels and chemicals through
jointly applied conversion technologies.
This work provides a comparison between a biorefinery system and a conventional fossil
reference system by means of Life Cycle Assessment (LCA). The biorefinery system is
based on a lignocellulosic feedstock (forest wood harvested in Central Norway) and
produces transportation biofuels, chemicals, electricity and heat. The assessment
investigates some key methodological aspects whose inclusion in LCA is very recent and
gathered increasing interest worldwide. These aspects are extremely important to ensure
the sustainability of biomass systems. These issues are:
• Estimation of changes in forest carbon stocks;
• Effects on GHG balance of C storage in long-life chemical products;
• Allocation of environmental impacts to the different co-products;
• Potential impact of forest wood collection on biodiversity.
Since climate change mitigation and energy security are the two most important driving
forces for bioenergy development, results have a focus on greenhouse gas (GHG) and
energy balances, with an estimation of the possible GHG and energy savings. Other
environmental impacts (like acidification, eutrophication, ozone layer depletion and
human/ecosystem toxicity) are analyzed according to the CML method.
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Renewable Motor Fuels: Thermochemical Conversion in the
Context of a Lignocellulosic Biorefinery.
T. Barth (Tanja.Barth@kj.uib.no), M. Kleinert (Mike.Kleinert@kj.uib.no),
L. Liguori Bjørsvik (Lucia.Liguori@kj.uib.no), A-M Hilmen (Annmari.
Hilmen@student.uib.no)
University of Bergen, Norway
B4: Thermochemical conversion mechanisms and technologies for biofuels applications
Background and objectives:
The main difference between motor fuels from fossil sources and biofuels lie in the
oxygen content. Biomass consists of approximately 1/3 oxygen by mass, most of which
needs to be removed in the conversion to a high quality fuel. Thermochemical
conversion is a central technology in production of liquids from biomass sources, and
improved processes that decompose the biopolymers with simultaneous oxygen removal
are needed. In a lignocellulosic refinery concept, ethanol production from carbohydrates
can be supplemented by thermochemical conversion of the lignin-rich residues. Recent
research has shown that heating in a reaction medium of ethanol with formic acid added
as a hydrogen donor produces an oil with a very low oxygen content (LtL oils).1 For
upscaling, a more detailed understanding of the chemical conversion pathways and the
factors determining the composition of the product and their quality as a fuel is needed.
Moreover, economic aspects require reduced use of solvent and hydrogenation agent.
The objective of the project is to develop this process to improve yields of highquality
oil and additional value-added products at economically viable conditions.
Methodology:
Small-scale experiments with various biomass qualities, including both pure lignin and
whole biomass, have been performed using experimental designs. Supplementary
hydrogen addition, catalysts and variation in the time-temperature-pressure conditions for
the process have also been investigated, and the amount and quality of the products are
evaluated relative to the inputs. Improved understanding of the chemical mechanisms is
provides the basis for selection of process conditions.
Outline of results:
The yields and composition of the LtL oils were explored as a function of the reaction
conditions, and show a high quality compared to the products obtained from other
thermo-chemical conversion routes. The results show that the purity of the lignin input is
not a limitation for the conversion process since any proportion of lignin and carbohydrate
residues can be used. The reaction conditions and mechanisms limit the number
of candidate catalysts, and the importance of Fischer-Tropsch type reactions in the
production of hydrocarbons during the reaction must be considered. Overall, the process
shows a high potential for valorising the wastes from an ethanol-producing biorefinery.
Reference: 1: M. Kleinert and T. Barth, Energy Fuels 22, 1371 (2008)
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The chemistry of the lignin to liquid (LtL) conversion process
Bjarte Holmelid (bjarte.holmelid@kj.uib.no)
Mike Kleinert (mike.kleinert@kj.uib.no)
Tanja Barth (tanja.barth@kj.uib.no)
Department of Chemistry, University of Bergen, Allégt 41, NO-5007 Bergen, Norway
Purpose
Develop, on the molecular level, a fundamental understanding of the direct one-step
depolymerisation pyrolysis process of lignin to liquid (LtL-process).
Methodology
The one-step high yielded pyrolysis of lignin at high temperature and pressure in the presence of
HCO2H/ROH furnish a liquid bio-oil with a total overall high C/H-ratio and a low O/C-ratio from
an almost complete depolymerisation of the solid material. The resulting non-acidic bio-oil
formed in this hydro-deoxygenating reaction of the solid phase can be described schematically
(Figure 1).1 The reaction is studied with respect of reactive intermediates and the product mixture
is analysed thoroughly to elucidate its structural components and the compounds formed in the
LtL depolymerisations are mainly substituted phenolics and aliphatics (normal and branched) and
small amounts of ketones and esters.1
Figure 1; Schematic representation of the LtL process
Results
A number of substituted benzyl protected phenols (simple lignin substitutes) have been
synthesised and the reactions of these lignin model compounds mechanistically demonstrate
possible reaction pathways for the lignin depolymerisation process and give a reasonable
explanation of the formation of the reaction products. The results from experiments with lignin
model compounds have given new insight in the depolymerisation process from lignin to liquid
bio-oil and also demonstrate the value of the LtL process as a source to fine chemical
production.2
1 M. Kleinert, T. Barth, Energy Fuels 2008, 22 (2), 1371-1379
2 M. Kleinert, T. Barth, Chem. Eng. Technol. 2008, 31, 736-74
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POSTER PRESENTATIONS
Renewable Energy in Transportation
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Optimal operational conditions for hydrogen production using Palm Oil Mill
Effluent (POME)
*Marzieh Badiei, Jamaliah Md. Jahim, Nurina Anuar , Siti rozaimah sheikh abdulah
Department of Bioprocess Engineering, Faculty of Engineering, 43600 Bangi, UKM , Selangor, Malaysia
* mbadiei@vlsi.eng.ukm.my
Direct utilization of palm oil mill effluent (POME) as a substrate without any supplement for the
production of molecular hydrogen using mesophilic anaerobic mixed culture, was successfully
established. The sample of mixed anaerobic culture was subjected to usual heat treatment at
85°C for 30 min. to enrich the microflora and enhance the microflora ability to degrade organics and
enhance hydrogen production efficiency. A mixed culture is more viable than a pure one in
hydrogen fermentation from organic wastes. Then
pre-treated microflora was acclimatized to
survive the hydrogen producing bacteria optimally. Effects of the variable initial pHs and
different concentrations of POME as substrate were evaluated to find the optimal conditions
favor the growth of mesophilic organisms that play important role in the conversion of POME
contents to hydrogen. At the optimal pH of 6.8, the biogas comprised 59% of hydrogen with a
yield 2761 ml H 2 . L -1 POME and a production rate 491 ml H 2 .L -1 POME.h -1 . Major constituents
of effluent were found as acetic acid, propionic acid, and butyric acid. The generated biogas was
free from methane. It is concluded that POME sludge is a good microflora source for efficient
hydrogen production from POME by properly controlling the environmental conditions. It was
also found the initial pH have an important effect on both hydrogen production yield and hydrogen
production rate.
Key words: POME, mesophilic, mixed anaerobic culture, microflora
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Isolation and characterization of ligninolytic microbes from termite’s
gut.
Cheng-Yu Ho 1 , Jui-Jen Chang 2 , Tsu-Yuan Chin 1 , Chieh-Chen Huang 1, *
1 Department of Life Sciences, National Chung Hsing University,Taichung, Taiwan
2 Genomics Research Center, Academia Sinica, Taiwan
Co-coresponding authors : cchuang@dragon.nchu.edu.tw
Termites thrive in great abundance in terrestrial ecosystems and play important
roles in bio-recycling of lignocellulose. Lignocellulosic materials are formed by three
main polymeric constituents including cellulose, lignin, and hemicelluloses. Because
of their intestinal flora, termites are among the most important wood- and litterfeeding
insects. The first aim of this study was to understand the composition of the
microbial flora from termite guts of the termite Coptotermes formosanus by DGGE
analysis. The results proved that potential lignocelluloses-degrading bacteria :
anaerobic and facultatively anaerobic bacteria readily existed in the hindgut of
termites. However, DGGE studies have revealed that the majority of these gut
symbionts have not yet been cultivated are identified. The second aim of study was
isolation and characterization of these lignocelluloses degradation related bacteria.
The result indicated that an isolate 1-8 from the termite guts of C. formosanus
exhibited endocellulase, protease, lipase, amylase, peroxidase and lignin peroxidase
activity. Subsequently, 16S rRNA gene sequencing showed 99% base sequence
homology and it was identified as Bacillus cereus (AF385082. 1). Under aerobic
condition, the growth density of Bacillus cereus 1-8 cultured in 1000ppm lignin
contented MSM medium is two times higher than cultured in MSM medium without
lignin. For the industrial application, the pretreatment of lignocellulosic materials is
required, which produce fermentational inhibitors like furfural, catechol and
hydroxylmethyl furfural. So the third aim was to test the tolerance of furfural and
catechol of the isolated bacterium. Maximum furfural tolerance of Bacillus cereus 1-8
was 20mM and could also degrade catechol in MSM medium containing 1mM. HPLC
analysis confirmed that Bacillus cereus 1-8 could degrade 98% furfural in medium
containing 15mM furfural.
Reference
Brune, A., Miambi, E., and Breznak, J. A., Roles of oxygen and the intestinal
microflora in the metabolism of lignin-derived phenylpropanoids and other
monoaromatic compounds by termites. Appl. Environ. Microbiol., 61, 2688–2695
(1995).
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Characterization of Bio-oils from Lignocellulose Using
Advanced Analytical Techniques and Data Analysis
James R. Gasson * a , Mike Kleinert a , Tanja Barth a & Ingvar Eide b
James R. Gasson, E-mail: james.gasson@kj.uib.no, Tel: +47 555 83480, Fax: +47 555 89490
Mike Kleinert, E-mail: mike.kleinert@kj.uib.no
Tanja Barth, E-mail: tanja.barth@kj.uib.no
Ingvar Eide, E-mail: ieide@statoil.com
a University of Bergen, Department of Chemistry, Allégaten 41, N-5007 Bergen, Norway.
b Statoil Research Centre, N-7005 Trondheim, Norway.
B4: Thermochemical conversion mechanisms and technologies for biofuels applications
Work Objective: Development of biofuels and bulk chemical production from renewable
sources comprises a very interesting, and very complex, field of research at present. Lignocellulosic
biomass is a most promising input, being an abundant alternative to energy crop
sourced productions and fossil products. One approach is the lignin to liquid (LtL) process,
which produces a petroleum compatible liquid fuel from lignin-rich residues in a convenient
one-step reaction. The high temperature and high pressure reaction in an alcoholic solvent
medium with formic acid as in situ hydrogen donor yields a large variety of phenols, esters,
ketones and aliphatic hydrocarbons in a non-acidic liquid with little or no amount of char
produced. 1 However, the composition of the LtL fuel is different than conventional fossil and
bio-based fuel products. The objective of this work is to use different analytical techniques
and data analysis to map the differences in chemical composition and relate the variation to
the range of input, process and product quality parameters that have been tested.
Methodology: The characterization of the bio-oils and their dependence on the starting
material and reaction parameters are addressed using newly developed analytical procedures.
These include the combined use of advanced analytical techniques (mass spectrometry) and
data analysis (chemometrics) to classify the oils in terms of chemical composition. 2,3 This will
play an especially vital role for the further application of the bio-oils as fuels or as a source of
bulk chemicals.
Results: The results are models coupling data from different analytical approaches using
chemometric evaluation of high quality bio-oils from different ligno-cellulosic materials. The
influences of different starting materials and treatments of the products are determined and
evaluated. Product quality differences are compared, and the first predictive models are
presented. The analytical approaches can be seen as preliminary steps to convert analytical
chemical information into important physical properties, exemplified by acid number
measurements.
1 M. Kleinert, T. Barth, Energy Fuels 2008, 22, 1371.
2 I. Eide, K. Zahlsen, Energy Fuels 2007, 21, 3702-3708.
3 M. Kleinert, J. R. Gasson, I. Eide, A.-M. Hilmen, T. Barth, Cellulose Chemistry and Technology 2009, accepted.
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Field trials of Biodiesel (B20) and Diesel Fuelled Direct Injection Tier-III
Compliant off Road Vehicles in Indian Conditions
Authors
Parthiban.A, Mahindra & Mahindra Ltd
Balamurugan.S, Mahindra & Mahindra Ltd
Krishnamoorthy.R, Mahindra & Mahindra Ltd
Abstract
An experimental investigation is conducted to evaluate the use of soya methyl ester (SME) of soya origin
as supplements in the diesel fuel at blend ratios of B20 in a fully instrumented, four cylinder, TCIC, Direct
injection (DI) Mahindra Tractor vehicle trials conducted at Mahindra field site jaitsar. The tests are
conducted using B20 Blend at different environmental and various field operation conditions. After
completion of field trials tractor PTO performance and engine performance & emission compared with
baseline data and also engine were dismantled for assessment of carbon deposits and wear of various
vital components/parts. Results shows that SME oil based biodiesel can be effectively used as an alternate
fuel in exiting diesel engine without any significant engine hardware modification.
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A novel monolithic catalyst for the transesterification of
vegetable oils to produce Biodiesel
Deborath M. Reinoso (dreinoso@plapiqui.edu.ar), Jorge M. Marchetti
(jorge.marchetti@chemeng.ntnu.no), Gabriela M. Tonetto
(gtonetto@plapiqui.edu.ar)a
Planta Piloto de Ingeniería Química PLAPIQUI (UNS-CONICET), Camino La
Carrindanga Km 7, CC 717, CP 8000, Bahía Blanca, Argentina.
Chemical Engineering Department. Faculty of Natural Science and Technology of
Norway. Sem sealands v. 4 NO-7491 Trondheim, Norway
Biodiesel is an alternative source of renewable energy with similar characteristics to
petroleum-derived diesel. The advantages of using a heterogeneous catalyst are
numerous: its reutilization, the possibility to use several raw materials with different
purity, downstreaming purification is simpler, soaps are not produced, and the reaction
time is shorter, among others. In this work, a novel structured catalyst is presented.
Methodology: A K/Al2O3 powder catalysts prepared by incipient-wetness impregnation,
and their parent cordierite monolithic catalyst produced by the dipcoating technique were
used for biodiesel production. The samples were characterized by X-ray diffraction,
atomic spectroscopy, surface electronic microscopy, N2 adsorption, DRIFT of CO2
adsorption. The catalyst were studied in the transesterification of soybean oil with
methanol at 60°C and 500RPM, with a alcohol/oil molar ratio = 30, and a catalyst load =
1 wt% for the powder catalyst and 0.5wt% for the monolith.
Outline of results:
The K load of the powder catalyst was 5.7%wt. Figure 1 shows the SEM image of a
vertical cut over the catalyst wall for the K/Al2O3-cordierite monolithic catalyst. The
thickness of the deposited catalyst layer was approximately 15m.
The powder catalyst presented a FAME yield of 73 and 64% for its first and second use
respectively, after 5h of reaction. Comparing the monolithic sample to the powder
catalyst (under the same reaction conditions),
the FAME yield was of 58% and 60.5%
respectively. The leaching tests indicated that
is lost in the first two tests, remaining stable
the next three tests. It is inferred that the
homogeneous species generated in the
reaction played an important role
in the activity.
The present work shows that the use of
monolithic catalysts in the transesterification
vegetable oils is a viable alternative.
Figure 1. SEM image for a vertical cut f the
catalyst wall K/Al2O3 (Mag: 361X).
K
in
of
Renewable Energy Research Conference 2010 142

The Centre for Renewable Energy
NTNU - SINTEF - IFE
A Reasonable Alternative Fuel for Diesel Engines; Pistacia
Terebinthus Biodiesel (PTB) and Its Blends with Diesel Fuel
Mustafa Ozcanlia (ozcanli@cu.edu.tr),
Ali Keskinb (alikeskin@mersin.edu.tr),
Hasan SERNa (hserin@cu.edu.tr),
Kadir Aydina (kdraydin@cu.edu.tr)
Department of Mechanical Engineering, Cukurova University, Adana, Turkey
Tarsus Technical Education Faculty, Mersin University, Mersin, Turkey
Biodiesel is an alternative diesel fuel which can be produced from a great variety
of feedstocks. Today, researchers are looking forward to use new sources as raw
materials for the biodiesel production. From this point of view, an experimental study
was conducted to evaluate the use of Pistacia Terebinthus oil Biodiesel (PTB) and its
blends with diesel fuel. Pistacia Terebinthus (Terebinth) oil was extracted by using
Soxhalet Extraction method. Free fatty acid content of PT oil was determined and
therefore PTB was produced via the alkali-catalyzed transesterification method. Methanol
was used as an alcohol and sodium hydroxide was used as a catalyst for the reaction.
Biodiesel produced from PT oil was blended with diesel fuel with volumetric ratio of 5%
(B5), 10% (B10), 25% (B25), 50% (B50) and 100% (B100). Various properties of the
biodiesel and blends such as density, calorific value, cetane number, cloud point,
kinematic viscosity, flash point, copper strip corrosion and sulfur content were
determined. Fuel properties were compared well with European and ASTM biodiesel
standards. Results show that while PTB can be directly used in compression ignition
engines according to ASTM standards, B50 is the best blend for European standards
because of viscosity value (5.72 cSt) of biodiesel.
Renewable Energy Research Conference 2010 143

The Centre for Renewable Energy
NTNU - SINTEF - IFE
Comparison of biodiesels based on different vegetable oil
with diesel in a experimental boiler
Bahamin Bazooyar a (Bazooyar.bb@gmail.com),
Afshin Ghorbani b (Afshinghorbani@yahoo.com),
Ahmad Shariati c (Ahmad_shariati@yahoo.com)
Petroleum University of Ahvaz
Petroleum University of Ahvaz
Petroleum University of Ahvaz
The world tendency in last years is to restrict the use of fossil fuels and replace them
partially or totally by renewable fuels. Accordingly, biodiesel is being studied as one
of the main alternatives and the production and consumption of this pure biofuel and
its binary blends with fossil diesel have been markedly grown. Consequently, the aim
of this study intended to examined the aspects of combustion performance and
emissions of biodiesel fuels made from different oils relative to the diesel fuel in a
experimental boiler. The combustion efficiency, c, and exhaust temperature, Texh, as
well as the common pollutants and emissions were tested over a wide range of air/fuel
ratio ranging from very lean to very rich. All tests were conducted at same level of
energy input for the fuels. The findings showed that at the tested level of input energy,
biodiesel combustion efficiency was a little inferior to that of diesel fuel due to its
higher density and lower heating value while on the other hand, from emissions view
points, biodiesel emitted less pollutants at the whole range of A/F ratio considered.
Renewable Energy Research Conference 2010 144

The Centre for Renewable Energy
NTNU - SINTEF - IFE
Use of renewable energies in irrigated canola production in Iran
Ali Mohammadi * , Shahin Rafiee
1 Department of Agricultural Machinery Engineering, Faculty of Agricultural
Engineering and Technology, University of Tehran, Karaj, Iran
* Corresponding author E-mail: mohammadia@ut.ac.ir
Abstract
Energy analysis, along with economic and environmental analyses, is an important tool to
define the behavior of agricultural systems. This paper studies the energy balance between the
input and the output per unit area for canola production in Golestan, Iran. For this purpose, the
data were collected from 83 canola farms in Golestan province. Inquiries were conducted in a
face-to-face interviewing October and November 2007 period. Mean canola yield were 2966.14,
it obtained under normal conditions on irrigated farming, and taking into account the output
energy. The results indicated that total energy inputs were found to be f 34742.18 MJ ha -1 .
Results further implied that about 76 % of total energy input was in non-renewable energy form,
and only 24% was in renewable energy form. Of all renewable energies, share of seeds, farmyard
manure and human labour energy were obtained 23.61%, 42.37%, and 34.02%, respectively. It
is suggested that specific policy is to be taken to increase canola crop production by raising
partial productivity of energy inputs without depending on mainly non-renewable energy sources
such as chemical fertilizers and chemical biocides that create environmental risk problems.
Keywords: Renewable energy, Farmyard manure energy, Environmental, Iran
Renewable Energy Research Conference 2010 145

The Centre for Renewable Energy
NTNU - SINTEF - IFE
Composite of Conducting Polymers and Aligned CNT for
Energy Storage
Fan Huang a (fanh@nt.ntnu.no)
Estelle Vanhaecke a (estelle.vanhaecke@chemeng.ntnu.no)
De Chen a (de.chen@chemeng.ntnu.no)
a Department of Chemical Engineering, Norwegian University of Science and Technology
Renewable energy production and storage is among the most important topics nowadays.
Carbon nanostructures have drawn an intensive attention because large aspect ratio, high
chemical stability and high electrical conductivity of carbon nanotubes and electro-chemical
properties of conducting polymers can contribute to applications such as supercapacitors,
batteries and solar cells [1-3]. The composite in this study is made via in-situ polymerization,
either through chemical polymerization or through electro-polymerization. PANI is in-situ
polymerized with aligned CNTs supported on foils. In-situ electro-polymerization is carried
by using cyclic voltammetry method in the 1M H 2 SO 4 electrolyte with various of sweeping
rates. Coating morphology is characterised by SEM and TEM. Chemical composition of the
coating is studied by Raman. Thermal properties are examined by TG, DSC carried out in the
air gas flow. The SEM and TEM photos confirm the presence and show the morphology of
the polymer coating on the CNTs. Raman spectra indicate the chemical composition of the
polymer on the CNTs. TG tests show the thermal stability of the composites. The
charge-discharge property, specific capacitance and electro-chemical stability properties are
studied via cyclic voltammetry. This type of composite show the superior potential to be used
as supercacitor and battery.
References
[1] S. Fan, M.G. Chapline, N.R. Franklin, T.W. Tombler, et al. Science 283 (1999) 512.
[2] S. Frank, P. Poncharal, Z.L. Wang, W.A. de Heer, Science 280 (1998) 1744.
[3] S.J. Tans, A.R.M. Verschueren, C. Dekker, Nature 393 (1998) 49.
Renewable Energy Research Conference 2010 146

The Centre for Renewable Energy
NTNU - SINTEF - IFE
Nanocrystalline Mg-SiC for Hydrogen Storage Material Obtained by
Mechanical Alloying
Zulkarnain Jalil 1# , Adi Rahwanto 1 and Mustanir 2
1 Department of Physics, University of Syiah Kuala, Banda Aceh, INDONESIA
2 Department of Chemistry, University of Syiah Kuala, Banda Aceh, INDONESIA
# Corresponding author: zkarnain03@yahoo.com
ABSTRACT
Regarding the use of hydrogen in fuel cell for mobile or stationary applications, metal hydrides
can offer a high hydrogen volume capacity and a safe alternative compared with liquid storage or
with compressed gas. Among the metal hydrides, magnesium is considered as one of potential
hydrogen storage materials because of its high capacity (7.6 wt%), lightweight and low cost.
However, high work temperature, slow reaction kinetics and hard activation process limit the
practical application of Mg-based hydrides. Recently, the high energy ball milling was
successfully introduced to prepare hydrogen storage materials. In this work, Mg catalyzed with
SiC was synthesized by using vibratory type ball milling to produce the nanocrystalline materials.
As the results, structural characterization by XRD showed that after 180 hours of milling time the
crystallite size decreases around tens nanometer. This can be noted that the intensive mechanical
alloying showed an interesting way to synthesize the magnesium based hydrogen storage
material. From SEM images of the sample powder before and after several hours of milling times
can be seen that the surface of the powders is very irregular, as a result of the repeated fracturing
events during the milling process.
Keywords: hydrogen storage, magnesium, metal hydrides, ball milling.
Renewable Energy Research Conference 2010 147

The Centre for Renewable Energy
NTNU - SINTEF - IFE
Theoretical and Experimental Investigation of Performance
Analysis on Diesel Engine Fuelled with Blends of Fischer-
Tropsch (F-T) Synthetic Diesel and Jatropha Methyl Ester
Dhandapani Kannan (dhandapani.kannan@ntnu.no),
Terese Løvås (terese.lovas@ntnu.no)
Department of Energy and Process Engineering,
Norwegian University of Science and Technology (NTNU), Norway
In the present scenario automotive industries, energy producers and researchers are
looking for an alternative source to replace fossil fuels due to environmental issue.
During the past few decades, there have been continuous efforts to improve the bio-fuels
(biodiesel, biogas, alcohol) and synthetic diesel fuels or Fischer-Tropsch (FT) processed
fuels to meet the emission regulations. In this work, the performance of Jatropha Methyl
Ester (JME) and Fischer-Tropsch synthetic diesel fuels were investigated employing
theoretical power cycle analysis of a diesel engine, and compared to the performance of
conventional diesel fuels. The numerical analysis has been compared to equivalent
experimental results.
The main objective has been to identify the impact on the power cycle performance due
to fuel quality. The chemical structure of the fuel was modeled using the exact element
ratio based on experimental fuel analysis. During the engine simulation, engine
geometry, compression ratio and heat loss due to combustion were kept constant
throughout the comparison. However, the lower heating value of the fuel, fuel
composition and mass of fuel supplied were varied according to fuel quality and blending
ratio. Due to the lower heating values of JME blends compared to FT and diesel fuel, the
mass of fuel supply was not maintained constant for JME, FT and diesel blends for the
same engine loads. This was done in order to obtain a more realistic scenario of similar
power output from employing the different fuels. However, the fuel quality of JME
blending percentage was in overall not found to have significant deteriorating impact on
engine performance.
Keywords
Fischer-Tropsch Synthetic Diesel; Jatropha Methyl Ester; Simulation; Experimentation;
Performance analysis.
Renewable Energy Research Conference 2010 148

The Centre for Renewable Energy
NTNU - SINTEF - IFE
The Renewable Energy Research Conference Abstract
Technological innovation and new product development in
bioethanol industry
Darius Sargautis a (darius@padomulapas.lv)
Tatjana Volkova a (Tatjana.Volkova@ba.lv)
a BA School of Business and Finance
Existing bioethanol production from grain, wheat and triticale, suppose standard
production process with well known production stages and final products – bioethanol
and co-product Distiller's Dried Grains with Solubles (DDGS). The new one innovative
production technology represents the different sequence of bioethanol production process
cycles with new one end product – high quality protein concentrate. At the new process
the fermentation broth is separated to biomass and liquid before distillation, meanwhile at
the standard process the fermentation broth is sent directly to the distillation and after
distillation goes to the separation. Regarding this innovative process, the new protein
product, which contains more than 55 % of crude protein, was developed. The developed
protein product has bigger market value in comparison with traditional co-product
DDGS. Also, the bioethanol production, using this innovative technology has
technological advantages, like handling of distillation and evaporation systems, because
the proteins and yeasts were separated before distillation and the working time without
cleaning is prolonged several times.
The bioethanol producer, using described technological innovations can
successfully compete in EU bioethanol market. The new protein product is selling as
niche product and has big opportunity for further developments, as the high protein
products have big demand, and it is suitable for all kinds of animals, as well.
The described innovative technology is successfully installed in the bioethanol
plant in Iecava, Latvia.
Keywords: innovation, bioethanol from grain, high protein.
Renewable Energy Research Conference 2010 149

The Centre for Renewable Energy
NTNU - SINTEF - IFE
ABSTRACTS
Zero Emission Buildings
Renewable Energy Research Conference 2010 150

The Centre for Renewable Energy
NTNU - SINTEF - IFE
Proposal of a Norwegian ZEB definition: Storylines and Criteria
I. Sartori a* , I. Graabak b and T.H. Dokka a
a SINTEF Building and Infrastructure P.O. Box 124, N-0314 Blindern, Oslo, Norway
b SINTEF Energy Research, Sem Saelands vei 11, Trondheim , Norway
* corresponding author, tel: +47 22965541, email: igor.sartori@sintef.no
ABSTRACT
A clear and agreed definition of Zero Emission Building (ZEB) is yet to be achieved, both
internationally and in Norway. However, it is understood that both the definition and the
surrounding energy supply system will affect significantly the way buildings are designed to
achieve the ZEB goal. Since the energy system in Europe is expected to change significantly
in the coming decades, especially for electricity, it is indispensable to tie the definition of
ZEB to possible scenarios on such development of the energy system. A scenario is defined as
a combination of options chosen within a framework of different uncertain futures. Two
uncertainties are identified as most important for the development and deployment of ZEB:
Technology development and Public attitude. These two uncertainties are used to span out a
set of four relevant futures, also termed storylines, as a common background for scenario
analysis. A formal definition of ZEB is characterized by a set of criteria that are: the system
boundary, feeing-in possibilities, balance object, balancing period, credits, crediting method,
energy performance and mismatch factors. For each criterion different options are available,
and the choice of which options are more appropriate to define ZEBs may depend on the
storyline features.
Keywords: ZEB definition, scenarios, storylines.
Renewable Energy Research Conference 2010 151

The Centre for Renewable Energy
NTNU - SINTEF - IFE
North European Understanding of Zero Energy/Emission Buildings
A.J. Marszal a , J.S. Bourrelle b ,
J. Nieminen c , A. Gustavsen b , P. Heiselberg a
a Aalborg University
b Norwegian University of Science and Technology
c VTT Technical Research Centre of Finland
ABSTRACT
The worldwide CO2 emission mitigation efforts, the growing energy resource shortage and
the fact that buildings are responsible for a large share of the world’s primary energy use
drives research towards new building concepts, in particular Zero Energy/Emission Buildings
(ZEBs). Unfortunately, there is a lack of a common understanding for this new type of
building which results in most countries to have their own, unique approaches. This paper
presents the northern (Danish, Finish, Norwegian and Swedish) understanding of ZEBs and
gathers together information related to ZEBs in these countries. Generally, we may observe a
correlation between the zero energy/emission building approach adopted by a country and this
particular country’s utility grid characteristics. Moreover, it is to be noted that the ZEB
concept is not well defined at the national level in northern Europe and that all of the
participating countries are still to adopt a national definition for these types of buildings. This
results in more than one understanding of ZEBs in each country.
This study provides a concise source of information on the north European understanding of
zero energy/emission buildings. It puts forward a number of similarities among the four
studied approaches while highlighting that each country adopts a slightly different ZEB
concept depending on its particular realities. This work may be viewed as a useful input to the
coordination of sustainable building research in northern Europe and as a good source of
information on different possible approaches towards ZEBs.
Keywords: zero energy building, zero emission building, Nordic countries, requirements,
multi-displinary.
Renewable Energy Research Conference 2010 152

The Centre for Renewable Energy
NTNU - SINTEF - IFE
ZEB Definition: Assessing the Implications for Design
I. Sartori a* , I. Andresen a and T.H. Dokka a
a SINTEF Building and Infrastructure, P.O. Box 124, N-0314 Blindern, Oslo, Norway
* corresponding author, tel: +47 22965541, email: igor.sartori@sintef.no
ABSTRACT
Conceptually a Zero Emission Building (ZEB) is a building with greatly reduced energy
demand and able to generate electricity (or other carriers) from renewable sources in order to
achieve a carbon neutral balance. However, a rigorous and agreed definition of ZEB is yet to
come. A parallel paper in this conference explains how a formal and comprehensive ZEB
definition can be based on the evaluation of certain criteria. These criteria are extensively
discussed in ongoing projects, both in Norway and internationally. The objective of this paper
is to focus on two of these criteria: energy performance and credits used to measure the ZEB
balance. For each criterion different options are considered and the implications they have on
the building design are assessed. The case study is on a typical Norwegian single family
house. It is shown that for certain choices on the two criteria options, a paradoxical situation
could arise. When using off-site generation based on biomass/biofuels, achieving the ZEB
balance may be easier for high energy consuming buildings than for efficient ones. This is the
exact opposite of what ZEBs are meant to promote: design of energy efficient buildings with
on-site generation options. Recommendations on how to avoid such a paradox are suggested.
Keywords: ZEB definition, design, low energy, passive house.
Renewable Energy Research Conference 2010 153

The Centre for Renewable Energy
NTNU - SINTEF - IFE
Renewable energy applications in zero emission buildings
– a case study
M. Haase a and V. Novakovic b
a NTNU, Department of Architectural Design, History and Technology, Trondheim, Norway
b NTNU, Department of Process Engineering, Trondheim, Noray
ABSTRACT
The largest potential for decreasing green house gas emissions, and therewith mitigating the
effects of global climate change, comes from improving energy efficiency. Once this is done
an efficient way of renewable energy supply with low related CO 2 emissions is needed.
Utilizing solar power in buildings is a topic which received much attention in the past twenty
years. In Norway, the potential for building integrated solar applications have long been
underestimated. New building codes that will be published later this year (2010) will demand
a fraction of between 50% and 60% which shall be covered by renewable energy sources.
This paper investigates the potential of different renewable energy application (solar thermal,
PV, and wind) in commercial a building (office) for energy efficient buildings with very low
heating demand. A cost effectiveness analysis was done and a sensitivity analysis on some of
the input parameter was performed. In addition, CO 2 emissions from operation and production
phase were compared and evaluated.
The results show that some solar applications are more cost effective than others. To integrate
solar applications can help to find cost effective solutions that minimize total CO 2 emissions
of the building.
Keywords: energy supply, CO 2 emissions, renewable energy
Renewable Energy Research Conference 2010 154

The Centre for Renewable Energy
NTNU - SINTEF - IFE
A life cycle cost analysis of large-scale thermal energy storage technologies
for buildings using combined heat and power
K. Gaine and A. Duffy
School of Civil and Building Services engineering,
Dublin Institute of Technology, Bolton Street, Dublin 1.
ABSTRACT
Buildings account for approximately 40% of energy consumption and greenhouse gas (GHG)
emissions in developed economies, of which approximately 55% of building energy is used
for heating and cooling. The reduction of building-related GHG emissions is a high
international policy priority. For this reason and because there are many technical solutions
for this, these polices should involve significant improvements in the uptake of small-scale
energy efficient (EE) systems.
However the widespread deployment of many technologies, must overcome a number of
barriers, one of which is a temporal (diurnal or seasonal) mismatch between supply and
demand. For example, in office applications, peak combined heat and power (CHP) thermal
output may coincide with peak electrical demand in the late morning or afternoon, whereas
heating may be required early in the morning. For this reason, cost-effective thermal storage
solutions have the potential to improve financial performance, while simultaneously reducing
associated GHG emissions.
The aim of this paper is to identify existing thermal energy storage (TES) technologies and to
present and asses the economic and technical performance of each for a typical large scale
mixed development. Technologies identified include: Borehole Thermal Energy Storage
(BTES); Aquifer Thermal Energy Storage (ATES); Pitt Thermal Energy Storage (PTES) and
Energy Piles. Of these the most appropriate for large scale storage in buildings were BTES
and ATES because of they are relatively cheap and are installed under a building and do not
use valuable floor area A Heat transfer analyses and system simulations of a variety of BTES
systems are carried out using a Finite Element Analysis package (ANSYS) and energy
balance simulation software (TRNSYS) is to determine the optimal system design. Financial
models for each system are developed, including capital, installation, running and
maintenance costs. Using this information the unit costs of energy recovered from the storage
area are estimated. It was found that a deep BTES was the least economically attractive
solution for daily storage and that a medium depth in the region of 50 meters was the most
feasible with running costs of approximately €0.055 per kWh.
Keywords: Thermal energy storage; Combined heat and power; Life cycle cost; Borehole;
Renewable Energy Research Conference 2010 155

The Centre for Renewable Energy
NTNU - SINTEF - IFE
The impact of domestic load profiles on the grid-interaction of building
integrated photovoltaic (BIPV) systems in extremely low-energy dwellings
R. Baetens a , R. De Coninck b,c , L. Helsen b & D. Saelens a
a Division of building physics, Department of civil engineering, K.U.Leuven,
BE-3000 Leuven, Belgium
b Division of applied mechanics and energy conversion, Department of mechanical
engineering, K.U.Leuven, BE-3000 Leuven, Belgium
c 3E, BE-1000 Brussels, Belgium
ABSTRACT
A BIPV system may produce the same amount of electricity as consumed in the building on a
yearly base, however the simultaneity of production and consumption needs to be evaluated.
The present paper aims at quantifying the impact of domestic load profiles on the integration
of building-integrated photovoltaic (BIPV) electricity generation in a Belgian climate.
In this work, a multi-zone TRNSYS model for a dwelling with compression heat pump for
both space heating and domestic hot water (DHW), domestic consumers and on-site
photovoltaic generation is set-up. As a consequence of the dynamics of the electricity demand
and supply, it is necessary to use small time-steps. The model is used to assess the influence
of the user behaviour, the influence of the dimensioning of the heating installation and gridinteractions
on the auto-consumption of BIPV systems. Furthermore, bottle-necks for possible
large-scale implementation of on-site photovoltaic generation are illustrated.
The electricity consumption of a dwelling typically peaks when the habitants wake up and
arrive back home, whereas the BIPV system shows a profile depending on the local weather
and system characteristics. By putting the results of the requested and delivered power within
the same model, it is shown that the domestic load profiles due to human behaviour do not
coincide with the output of photovoltaic systems.
A dwelling with a classic gas-fired heating system is compared by a dwelling equipped with a
electricity-driven heat pump for space heating and DHW. Herefore, the cover factor is
defined, i.e. the ratio of domestic demand that is covered by the BIPV, for a BIPV installation
with a yearly electricity production that equals the yearly domestic demand. If no attempt is
made to bring the electricity demand and supply into balance on instant basis, a cover factor
of 0.42 is found if a classic heating system is installed, denoting that more than half of the
produced electricity will be passed on to the grid and withdrawn on another moment. If a heat
pump is used for space heating and DHW, the cover factor decreases to 0.29.
If one aims to drastically decrease the domestic electricity demands from the main distribution
grid, the installation of a BIPV might not be sufficient due to the imbalance of domestic
electricity demand on the production by the BIPV system. An integrated approach including
the current practice, the domestic installation, the mixture of loads and the grid is necessary.
Keywords: Domestic load profile, photovoltaic, BIPV, cover factor, smart grid
Renewable Energy Research Conference 2010 156

The Centre for Renewable Energy
NTNU - SINTEF - IFE
Towards an active, responsive and solar building envelope
F. Goia, M. Perino, V. Serra, F. Zanghirella
TEBE Research Group, Department of Energetics, Politecnico di Torino, Italy
ABSTRACT
The key role of the building envelope in achieving building energy efficiency and indoor
comfort for the user has been established since time. The most promising – and innovative –
strategy for the building envelope of tomorrow is based on a dynamic, active and integrated
solution, able to optimize the thermal performance, integrating active elements and systems,
exploiting energy from renewable source. Considerable efforts in research and development
are necessary to achieve a sustainable and effective building envelope with a dynamic
behaviour. Within the field of the light and transparent building envelope, a general trend in
research can be drawn: along with the innovation of the façade’s subsystems, researchers and
producers are moving from the double skin façade concept towards a more complex façade,
where the functional strategies are improved and the integration with active elements and the
HVAC system is deeper. The most relevant results of a decade-long research activity carried
out at the TEBE Research Group at Politecnico di Torino, on active and integrated building
envelope, are here presented. The analysis provides useful information about the contribution
of each subsystem – e.g. glazing, sun-shading devices, natural and mechanical ventilation... –
to the achieved energy efficiency and user thermal comfort. Furthermore, the paper also
presents the concept for an innovative façade module – which prototype is currently under
construction – conceived in the frame of a National Research Project. The ActResS module –
Active, Responsive and Solar module – is a dynamic building envelope element, capable of
changing its thermo-physical behaviour in order to maximize the energy efficiency and the
environmental comfort of buildings occupants.
Keywords: Double Skin Façades, Advanced Integrated Façades, Adaptive building envelope
technologies, Solar energy, Low energy architecture.
Renewable Energy Research Conference 2010 157

The Centre for Renewable Energy
NTNU - SINTEF - IFE
Equation Chapter 1 Section 1Accelerated Ageing of Vacuum Insulation
Panels (VIPs)
E. Wegger a , B.P. Jelle a,b , E. Sveipe a ,
S. Grynning b , A. Gustavsen c , J.V. Thue b
a Department of Civil and Transport Engineering,
Norwegian University of Science and Technology (NTNU), Trondheim, Norway
b Department of Materials and Structures,
SINTEF Building and Infrastructure, Trondheim, Norway
c Department of Architectural Design, History and Technology,
Norwegian University of Science and Technology (NTNU),Trondheim, Norway
ABSTRACT
Vacuum insulation panels (VIP) is a high performance thermal insulation material solution
with thermal conductivity values reaching as low as 4.0 mW/(mK). With time the thermal
performance of the VIPs will degrade as moisture and gas permeate through the barrier
envelope of the panels. To better evaluate these ageing effects, accelerated ageing
experiments are needed. VIPs consist of a porous core of pyrogenic silica (SiO 2 ) and a gas
and vapour tight envelope. The external factors that are found to contribute most to ageing of
VIPs are temperature, moisture and pressure.
Several experiments have been initiated to evaluate the acceleration effects by the application
of severe temperature, moisture and pressure conditions, including:
1. Thermal ageing at 80°C for 180 days according to CUAP 12.01/30
2. Exposure to cyclic climate in a vertical climate simulator according to NT Build 495. One
VIP sample is fully exposed in the simulator and one is placed in a wooden frame
structure.
3. Exposure to high vapour pressure by storage at 70°C and 90-100 % RH for 90 days.
The increases in thermal conductivity during ageing were relatively small compared to the
initial thermal conductivity of the VIPs, which is in agreement with the theoretical
predictions. The temperature and moisture experiment seemed to achieve a rather large
acceleration effect.
In addition, the thermally aged VIP and the exposed VIP in the climate simulator show
physical alterations. E.g. swelling, curving and delamination of the outer fire protection layer
are observed.
Keywords: Vacuum Insulation Panel, VIP, accelerated ageing, thermal insulation
Renewable Energy Research Conference 2010 158

The Centre for Renewable Energy
NTNU - SINTEF - IFE
Application of Vacuum Insulation Panels in Retrofitting of
Timber Frame Walls – An Experimental Investigation
E. Sveipe a , B.P. Jelle a,b *, E. Wegger a , S. Uvsløkk b , J.V. Thue a ,
S. Grynning b , O. Aunrønning a , E. Rognvik b , A. Gustavsen c
a Department of Civil and Transport Engineering, Norwegian University of
Science and Technology (NTNU), NO-7491 Trondheim, Norway.
b Department of Materials and Structures, SINTEF Building and Infrastructure,
NO-7465 Trondheim, Norway.
c Department of Architectural Design, History and Technology, Norwegian University of
Science and Technology (NTNU), NO-7491 Trondheim, Norway.
* Corresponding author: bjorn.petter.jelle@sintef.no (e-mail), 47-73-593377 (phone), 47-73-
593380 (fax)
ABSTRACT
A large amount of the buildings in Norway is from the 1970s. Many of these buildings have
timber frame walls and are now ready to be retrofitted. Application of vacuum insulation
panels (VIPs) can make it easier to improve the thermal insulation in building walls with a
minimal additional thickness. Retrofitting of buildings using VIPs may therefore be done
without large changes to the building, e.g. extension of the roof protruding and fitting of
windows. Additionally, U-values low enough to fulfil passive house standards or zero energy
building requirements may be achieved. Thus, contribute to a reduction of the energy use and
CO 2 emissions within the building sector. This work investigates two different ways of
retrofitting timber frame walls, one with VIPs on the cold side and one with VIPs on the
warm side. A wall module containing four different fields is built and tested between two
climate rooms with indoor and outdoor climate, respectively. The module consists of one
reference field representing a timber frame wall built according to regulations in the 1970s in
Norway, and three fields representing different ways of improving the thermal insulation of
the reference field with VIPs. As VIP is a vapour tight barrier, the fields are tested with
respect to condensation risk. A new sensor for measuring surface condensation called the
wetness sensor is introduced. The results of the experiment show that this method of
retrofitting may be acceptable in certain structures within limited climate zones, humidity
classes, and building envelopes.
Keywords: Thermal insulation, Retrofitting, Timber frame wall, Vacuum insulation
panel,VIP
Renewable Energy Research Conference 2010 159

The Centre for Renewable Energy
NTNU - SINTEF - IFE
User Evaluations of Energy Efficient Buildings –
Literature Review and Further Research
Å. L. Hauge a , J. Thomsen b and T. Berker c
a SINTEF Building and Infrastructure, P.O.Box 124 Blindern, 0314 Oslo, Norway
b SINTEF Building and Infrastructure, Alfred Getz vei 3, 7465 Trondheim, Norway
c Centre for society and technology, dep. of interdisciplinary studies of culture, Norwegian
university of science and technology, NTNU, 7491 Trondheim, Norway
ABSTRACT
This paper is based on a review of research that describes user experiences with different
types of energy efficient buildings, focusing on indoor climate, technical operation, user
attitudes, and general satisfaction. Energy efficient buildings are often rated better than
conventional buildings on indoor climate, but when investigating more thoroughly, the users
have different concerns. The varying results from the user evaluations reflect that the quality
of the buildings differs. However, user concerns may also be a result of inappropriate use.
Perceived personal control and sufficient information on operation and use is crucial for an
overall positive experience of the building. Three areas for further research could be
identified: There is a shortage of research that takes into account the social context for
evaluation. The social environment, the process of moving into an energy efficient building,
and prior knowledge on environmental issues, influences the evaluation of the building.
Energy efficient buildings may also require specific architectural solutions, and further
research should consider architectural and aesthetic aspects in the evaluation. Research on use
and operation of energy efficient buildings is increasing, but there is still a need to give more
detailed attention to different ways of providing information and training in operation and use.
Keywords: User evaluations, POE, energy efficient buildings, passive houses
Renewable Energy Research Conference 2010 160

The Centre for Renewable Energy
NTNU - SINTEF - IFE
Potential of passive cooling, natural ventilation and solar control in cold
climates office buildings
L. Finocchiaro a , T. Wigenstad b and A.G. Hestnes a
a Department of Architectural Design, History and Technology, NTNU, 7491 Trondheim
b Sintef Building and Infrastructure, 7465 Trondheim
ABSTRACT
The comparison between the exterior and the desired internal comfort conditions is not only
fundamental to understand which strategies might be adopted in a certain climatic context but
also determines the grade of complexity in the architectural design. If two different passive
strategies are usually necessary in temperate climates for overheated and underheated periods,
a simpler approach, aiming at maximizing the solar heat gain and minimize thermal losses
during the whole year, traditionally characterizes architectural design in cold climates. Today
the use of extremely air tight and insulating envelopes, in combination with the high internal
gains due to occupancy and equipment, is not only questioning the convenience of designing
compact shapes in cold climates but also determining the need of adopting strategies for
natural cooling, ventilation, and solar control in such climates. Most of those strategies are
commonly adopted in temperate or even hot climate contexts and, in order to work properly,
require external conditions sometimes not available in cold countries. These contradictions
are leading architectural design of cold climates office buildings into a new complexity.
In this study the results of an analysis conducted on the comparison between the thermal
comfort zone and cold climates is presented. The impact of both climate change and
technological development of new architectural components and materials on the definition of
the most appropriate passive strategy was investigated. Results showed that the spontaneous
thermal correction due to the heat production of internal loads has to been taken in account in
the preliminary analysis of the architectural design in order to define an efficient low energy
strategy.
Keywords: Climate, comfort, strategy, internal gains.
Renewable Energy Research Conference 2010 161

The Centre for Renewable Energy
NTNU - SINTEF - IFE
Efficient Building Operation as a Tool to Achieve Zero Emission Building
N. Djuric and V. Novakovic
Norwegian University of Science and Technology,
Department of Energy and Process Engineering, NO-7491 Trondheim, Norway
ABSTRACT
Quality control of the complete energy system is essential if CO 2 targets are to be met.
Building energy management systems (BEMS) provide information and means to monitor
building energy performance efficiently. Therefore, strategies and tools for ensuring that the
technical goal of zero emission buildings (ZEB) is robustly realized are necessary. Lifetime
commissioning (LTC) has been recognized as a tool that can perform quality control of
buildings. The aim of our study was to present LTC procedures and three assessment tools
that can be used for quality control of ZEB energy supply in operation phase. LTC procedures
were introduced using a generic framework on building performance. The three developed
assessment tools were: mass balance inspection algorithm for consumer substation, regression
model for predicting heating load based on outdoor temperature and building use, and
advanced method for improved measurement of heat pump performance based on data
integration. LTC procedures and tools were tested on two case studies. The results showed
that 20% of all the defined building performances can be monitored by BEMS. Using the
mass balance inspection algorithm, it was found that fault in mass balance prevented
implantation of desired temperature control for floor heating system. The regression models
based on sequential quadratic programming algorithm are very robust because they can be
extended with many parameters and functions. For heat pump performance, measurement of
differential water temperature can be very random, and the use of compressor electrical signal
can give more precise data on heat pump performance.
Keywords: lifetime commissioning, building performance, BEMS, data analysis
Renewable Energy Research Conference 2010 162

The Centre for Renewable Energy
NTNU - SINTEF - IFE
Nanotechnology and Possibilities for the
Thermal Building Insulation Materials of Tomorrow
B.P. Jelle a,b* , A. Gustavsen c , S. Grynning a ,
E. Wegger b , E. Sveipe b and R. Baetens d
a Department of Materials and Structures,
SINTEF Building and Infrastructure, Trondheim, Norway.
b Department of Civil and Transport Engineering,
Norwegian University of Science and Technology (NTNU), Trondheim, Norway.
c Department of Architectural Design, History and Technology,
Norwegian University of Science and Technology (NTNU), Trondheim, Norway.
d Department of Civil Engineering,
Catholic University of Leuven (KUL), Heverlee, Belgium.
* Corresponding author: E-mail: bjorn.petter.jelle@sintef.no, Phone: 47 73 59 33 77
The work presented within this article is based on B. P. Jelle, A. Gustavsen and R. Baetens,
”The Path to the High Performance Thermal Building Insulation Materials and Solutions of
Tomorrow”, Accepted for publication in Journal of Building Physics, 2010.
ABSTRACT
Nanotechnology and possibilities for the thermal building insulation materials of tomorrow
are explored within this work. That is, we are looking beyond both the traditional and the
state-of-the-art thermal building insulation materials and solutions, e.g. beyond vacuum
insulation panels (VIP).
Thus advanced insulation material (AIM) concepts like vacuum insulation materials (VIM),
gas insulation materials (GIM), nano insulation materials (NIM) and dynamic insulation
materials (DIM) are introduced and defined.
The VIMs and GIMs have closed pore structures, whereas the NIMs may have either open or
closed pore structures. The objective of the DIMs are to dynamically control the thermal
insulation material properties, e.g. solid state core conductivity, emissivity and pore gas
content.
In addition, fundamental theoretical studies aimed at developing an understanding of the
basics of thermal conductance in solid state matter at an elementary and atomic level will also
be carried out. The ultimate goal of these studies will be to develop tailor-make novel high
performance thermal insulating materials and dynamic insulating materials, the latter one
making it possible to control and regulate the thermal conductivity in the materials
themselves, i.e. from highly insulating to highly conducting.
Keywords: Nano insulation material, NIM, Vacuum insulation, Building, Tomorrow.
Renewable Energy Research Conference 2010 163

The Centre for Renewable Energy
NTNU - SINTEF - IFE
Nanoelectrochromics with Applied Materials and Methodologies
T. Gao a,* , A. Gustavsen, a and B.P. Jelle b,c
a Department of Architectural Design, History and Technology, Norwegian University of
Science and Technology (NTNU), Trondheim, Norway.
b Department of Materials and Structures, SINTEF Building and Infrastructure, Trondheim,
Norway.
c Department of Civil and Transport Engineering, Norwegian University of Science and
Technology (NTNU), Trondheim, Norway.
* Corresponding author: E-mail: tao.gao@ntnu.no
ABSTRACT
The application of electrochromic nanomaterials for smart windows is reviewed. The
scientific and technical issues related to material preparation and device assembly for largearea
and large-scale window applications are discussed.
Keywords: Electrochromism, Nanomaterials, Smart Windows
Renewable Energy Research Conference 2010 164

The Centre for Renewable Energy
NTNU - SINTEF - IFE
Dynamic Solar Radiation Control in Buildings by
Applying Electrochromic Materials
B.P. Jelle a,b * and A. Gustavsen c
a Department of Materials and Structures,
SINTEF Building and Infrastructure, Trondheim, Norway.
b Department of Civil and Transport Engineering,
Norwegian University of Science and Technology (NTNU), Trondheim, Norway.
c Department of Architectural Design, History and Technology,
Norwegian University of Science and Technology (NTNU), Trondheim, Norway.
* Corresponding author: E-mail: bjorn.petter.jelle@sintef.no, Phone: 47 73 59 33 77
ABSTRACT
Smart windows like electrochromic windows (ECWs) are windows which are able to regulate
the solar radiation throughput by application of an external voltage. The ECWs may decrease
heating, cooling and electricity loads in buildings by admitting the optimum level of solar
energy and daylight into the buildings at any given time, e.g. cold winter climate versus warm
summer climate demands.
In order to achieve as dynamic and flexible solar radiation control as possible, the ECWs may
be characterized by a number of solar radiation glazing factors, i.e. ultraviolet solar
transmittance, visible solar transmittance, solar transmittance, solar material protection factor,
solar skin protection factor, external visible solar reflectance, internal visible solar reflectance,
solar reflectance, solar absorbance, emissivity, solar factor and colour rendering factor.
Comparison of these solar quantities for various electrochromic material and window
combinations and configurations enables one to select the most appropriate electrochromic
materials and ECWs for specific buildings. Measurements and calculations were carried out
on two different electrochromic window devices.
Keywords: Solar Radiation, Glazing Factor, Electrochromic Window, Building,
Transmittance, Reflectance, Absorbance, Emissivity, Solar Material Protection Factor, Solar
Skin Protection Factor, Window Pane, Glass.
Renewable Energy Research Conference 2010 165

The Centre for Renewable Energy
NTNU - SINTEF - IFE
The Effect of Wall-Integrated Phase Change Material Panels
on the Indoor Air and Wall Temperature – Hot-box Experiments
S. Cao a,b,c , A. Gustavsen b,* , S. Uvsløkk c , B.P. Jelle c,d , and J. Maunuksela a
a Renewable Energy Program, Department of Physics,
P.O. Box 35 (YFL), FI-40014 University of Jyväskylä, Finland.
b Department of Architectural Design, History and Technology, Norwegian University of
Science and Technology (NTNU), Alfred Getz vei 3, NO-7491 Trondheim, Norway.
c Department of Materials and Structures, SINTEF Building and Infrastructure,
Høgskoleringen 7B, NO-7465 Trondheim, Norway.
d Department of Civil and Transport Engineering, Norwegian University of Science and
Technology (NTNU), Høgskoleringen 7A, NO-7491 Trondheim, Norway.
* Corresponding author’s email: Arild.Gustavsen@ntnu.no
ABSTRACT
Phase change materials (PCMs) have opened a new door towards the renewable energy future
due to their effective thermal energy storage capabilities. Several products have recently
found their way to the market, using various types of PCMs. This paper focus on one
particular wall-board product, integrated in a well-insulated wall constructed of an interior
gypsum board, PCM panel, vapor barrier, 300 mm mineral wool, and a wind barrier.
Experiments are conducted in a traditional guarded hot-box. The hot-box is composed of two
full-scale test chambers, where the tested wall is located between those two chambers. There
are two heaters inside the measuring box: heater 1 is used to maintain a constant temperature
(of about 20 ºC), while heater 2 is used to simulate some additional indoor heat sources such
as human heat, equipment and lighting (resulting in temperatures larger than 20 ºC). The cold
chamber has a fixed temperature equal to –20 ºC. The experiments are arranged in a
comparative way, i.e. comparing walls with and without a PCM panel. Temperature, velocity
and heat flow data are recorded during testing. By applying well-distributed thermocouples,
the influences of the PCM panel on the indoor temperatures can be shown. Furthermore, with
attached heat flux meters, the energy storage effect and convective heat flows can be
determined. Finally, with the electrical power meter, the energy saving effect can also be
calculated.
In this paper, initial experimental results are presented, showing the indoor air and surface
wall temperatures. The main purpose is to examine the effect of the PCM panel on the indoor
temperature as a function of various convection heat transfer rates on the indoor side. The
wall is tested with and without the PCM panel in order to get comparative results.
Keywords: Phase Change Materials (PCMs), Wall-integrated PCM, Energy Storage,
Experimental, Hot-box.
Renewable Energy Research Conference 2010 166

The Centre for Renewable Energy
NTNU - SINTEF - IFE
POSTER PRESENTATIONS
Zero Emission Buildings
Renewable Energy Research Conference 2010 167

The Centre for Renewable Energy
NTNU - SINTEF - IFE
An Efficient Numerical Method for Simulation of Long-term Operation of
Horizontal Ground Heat Exchangers with Parallel Shallow Pipes
M. Greene, J. Lohan, N. Burke, L. Dimache and R. Clarke
Centre for the Integration of Sustainable Energy Technologies (CiSET), Galway-Mayo
Institute of Technology (GMIT), Dublin Road, Galway, Ireland.
ABSTRACT
As part of the HP-IRL study a horizontal ground heat exchanger in winter mode was
simulated using the finite difference method in Cartesian coordinates. The authors have found
that while a finite difference liquid energy balance simulation of the heat exchanger is
accurate; fully transient and mimics real life, it is best suited for simulation of shorter system
on-times of hours or days, as it becomes cumbersome to simulate every meter of the heat
exchange fluid along with ground temperature distribution over long system on-times of
months. This paper demonstrates a simulation based on estimating the heat exchanger’s local
heat flux at the exit of the pipe in order to determine the fluid’s return temperature. For a
150m pipe this makes the calculation domain 150 times smaller than the liquid energy balance
domain meaning the method is more efficient to use when a ground source heat pump system
is to be simulated over long time periods such as months. It works best when the heat pump
system is running in an approximate steady state condition, meaning turned on for all or a part
of each day. Validation shows that the maximum error in hour average return temperature
prediction is 1ºC. This method along with the more common liquid energy balance method,
both in Cartesian coordinates, are currently in use as part the HP-IRL study to simulate new
heat exchanger designs in order to optimize system efficiency in Ireland’s maritime climate.
Keywords: Horizontal, Ground, Heat Exchanger, Numerical, Climate
Renewable Energy Research Conference 2010 168

The Centre for Renewable Energy
NTNU - SINTEF - IFE
Rock Core Samples Cannot Replace Thermal Response Tests - A Statistical
Comparison Based On Thermal Conductivity Data From The Oslo Region
(Norway)
H.T. Liebel a , K. Huber b , B.S. Frengstad c , R. Kalskin Ramstad d and B. Brattli a
a Department of Geology and Mineral Resources Engineering, Norwegian University of
Science and Technology (NTNU), NO-7491 Trondheim, email: heiko.liebel@ntnu.no
b Department of Geology, University of Bayreuth, Universitätsstr. 30, D-95440 Bayreuth,
Germany
c Geological Survey of Norway (NGU), NO-7491 Trondheim
d Asplan Viak AS, Postbox 6723, NO-7490 Trondheim
ABSTRACT
Borehole heat exchanger (closed-loop) systems coupled to a ground-source heat pump are
applied for space heating and cooling using the ground as energy source or storage medium.
For accurate dimensioning of a ground-source heat installation, knowledge of the thermal
conductivity of the subsurface is vital.
Thermal response tests (TRT) are widely used to measure the in situ thermal conductivity in a
well. Alternatively, the thermal conductivity in a borehole is approximated from rock core
samples based on lab measurements. Rock core data and thermal conductivity maps are
financially more attractive for planning purposes than expensive TRTs. The value of both
approaches was statistically tested using data from the geologically diverse Oslo region
(Norway).
Effective thermal conductivity data measured via TRTs show a clear trend towards higher
thermal conductivity values in comparison to lab measured thermal conductivity values from
rock cores (in 82 % of cases). The deviation from the rock core samples, however, varies
strongly as several geological layers may be represented in one single well. Furthermore, the
thermal conductivity of the rock core samples varies strongly within individual geological
units.
The comparison of both techniques of thermal conductivity measurement shows that the in
situ thermal conductivity at a location cannot be predicted from rock core data of a geological
unit.
The results of this study indicate that the dimensioning of a large ground-source heat project
cannot be based on rock core measurements or thermal conductivity maps only, without
analyzing the in situ thermo-, hydro- and geological conditions in fractured rocks.
Keywords: Thermal response test, thermal conductivity, ground-source heat, hard rock,
thermal conductivity map.
Renewable Energy Research Conference 2010 169

The Centre for Renewable Energy
NTNU - SINTEF - IFE
Utilisation of Geothermal Heat Pumps within Permeable Pavements for
Sustainable Energy and Water Practices
K. Tota-Maharaj a* , M. Scholz a and S.J. Coupe b
a Institute of Infrastructure and Environment, School of Engineering, University of Edinburgh,
William Rankine Building, The King’s Buildings, Edinburgh, UK. EH9 3JL
b Hanson Formpave Tufthorn Avenue Coleford Gloucestershire GL16 8PR
* corresponding author, email: k.tota-maharaj@ed.ac.uk
ABSTRACT
Global warming and climate change is a reality faces the world today and as a result increases
the use of sustainable practices for both energy and water minimising CO 2 emissions.
Geothermal heat pumps (GHPs) are an attractive proposition for renewable energy worldwide
as it uses energy naturally stored in the earth. The Earth is a very resourceful form of energy,
using the natural solar energy collection and heat storage capabilities as an infinite heat
source/heat sink at the base of permeable pavements can provide an excellent temperature
gradient for which the GHP’s harnesses. Two experimental rigs were setup up at The
University of Edinburgh for a combined permeable pavement and GHP system. At the base of
a pavement structure (approximately 1 meter) below the ground’s surface, temperatures are
constant of 10ºC in the U.K all year round. The GHP performance efficiency was analysed by
the coefficient of performance (COP) in a heating cycle and the energy efficiency ratio (EER)
in a cooling cycle. The Mean COP and EER for both systems averaged between 2-4.5 and 3-5
respectively. The combined GHP and pavement structure operated at an optimum efficiency
for both heating and cooling cycles and has shown to be unaffected by higher summer or
lower winter temperatures. This hybrid system is an attractive renewable energy technology
and has additional environmental benefits with regards to urban runoff reuse and recycling for
the production domestic hot water.
Keywords: earth energy systems, permeable pavements, pervious pavements, sustainable
urban drainage (SUDS), thermo-geologic efficiency.
Renewable Energy Research Conference 2010 170

The Centre for Renewable Energy
NTNU - SINTEF - IFE
Thermosyphon Heated Thermal Store, the Influences of Valve Opening on
flow, an Experimental Analysis
J. N. Macbeth a , H. Smith a , Dr. J. Currie b , Dr. N. Finlayson a
a Greenspace Research, Lews Castle College UHI, Stornoway, Isle of Lewis, HS1 0XR, UK
b Edinburgh Napier University, Schools of Engineering and the Built Environment, 10
Colinton Rd, Edinburgh, EH10 5DT, UK
ABSTRACT
This paper outlines initial findings from the design of a Thermal Energy Storage (TES)
system that’s principal objective is to promote stratification when charged by an intermittent
electrical supply. This concept will offer an efficient solution to the heating and provision of
domestic hot water within buildings when coupled with a renewable energy source such as
wind power.
The principal of operation is to add the energy to the tank through a side arm that creates a
thermosyphon and in turn returns the water to the top of the tank at a desired temperature. A
system of extraction points will then be employed, to prioritise the replenishment of
individual tank nodes from top to bottom, thus increasing the useful energy content of the
system.
In this paper initial investigations on the control mechanism required to achieve the desired
mass flow rate have been carried out experimentally on a 750litre tank. The tank was charged
under steady input power with different valve opening angles, the results from which show
the formation of temperature gradients through the tank’s vertical plane.
It is found that the importance of the valve opening lies mainly in permitting large changes in
the power inputs to the store. It also allows for small and large temperature rises to be
achieved across the side arm, thus enabling nodes to be “topped-up”. The requirements to
compensate for the changes in driving force are found to be less critical than first anticipated.
Keywords: Intermittent electrical supply, stratification, thermosyphon, charge-cycle.
Renewable Energy Research Conference 2010 171

The Centre for Renewable Energy
NTNU - SINTEF - IFE
Towards a zero emission built environment – M.Sc. programme in
sustainable architecture
A. Wyckmans
NTNU Norwegian University of Science and Technology, Department of Architectural
Design, History and Technology
ABSTRACT
At the Norwegian University of Science and Technology (NTNU) in Trondheim, an
international interdisciplinary M.Sc. programme in Sustainable Architecture starts in autumn
2010. The curriculum is based on long experience with graduate and post-graduate courses in
the field, which are now being bundled into one holistic education.
The M.Sc. programme aims to educate building professionals in the use and development of
competitive methods and solutions for existing and new buildings that will contribute to
lowering greenhouse gas (GHG) emissions related to the production, use, management, and
demolition of architecture in a life-cycle perspective.
Throughout the two years of the M.Sc. programme, a holistic perspective stresses the many
architectural expressions and possibilities encompassed within a zero emission built
environment. Within each of the theory and project courses, high demands are made towards
integrated design strategies to ensure usability and synergy of the design with its surroundings
and users. The students are continuously trained in interdisciplinary co-operation enabling
them to integrate these routines in their professional practice.
The paper describes the learning aims, course structures and pedagogical methods of the
M.Sc. programme. In addition, it focuses on the strong link with the Research Centre on Zero
Emission Buildings at NTNU, ensuring immediate contact with and transfer of high-quality
research and practice experiences in Norway and abroad: education and research institutions;
producers of materials and products for the building industry; contractors, consultants,
architects; trade organisations; public administration; public and private construction and
property management; and users.
Keywords: interdisciplinary, architectural design, professional role, lifecycle perspective,
zero emission
Renewable Energy Research Conference 2010 172

The Centre for Renewable Energy
NTNU - SINTEF - IFE
ABSTRACTS
Ocean Energy
Renewable Energy Research Conference 2010 173

The Centre for Renewable Energy
NTNU - SINTEF - IFE
Abstract d.d. 4 mei 2010 congres Noorwegen 7 juni 2010.doc
Blue Energy: from smart concept to promising technology
Prof.dr.ir. C.J.N. Buisman
Abstract
Reverse electrodialysis is a conversion technique to obtain electricity from salinitygradients.
Over the past few years, the performance of reverse electrodialysis on
laboratory scale has improved considerably. In this paper, we discuss the challenges we
are still facing concerning the economic and technological feasibility and the developing
path of reverse electrodialysis. We focus on the following issues: (i) the development of
low-cost membranes, (ii) the pre-treatment in relation to stack design and operation, and
(iii) the economics of reverse electrodialysis. For membranes, the challenge is to increase
availability (>km 2 /year) at reduced cost (

The Centre for Renewable Energy
NTNU - SINTEF - IFE
The Physics of Flow and Mass Transport in Salt Power: Towards
Improved Module Designs
J.G. Pharoah a (pharoah@me.queensu.ca),
S.M. Mojab a , A. Mahdavifar a , A. Pollard a , S. Beale b , E.S. Hanff b
a
Queen’s University, Kingston, ON, CANADA
b
Natural Research Council of Canada, Ottawa, ON, CANADA
Membrane modules for membrane separation are commercially available, yet the physics
of the the flow and mass transport is not well understood. A typical spiral wound membrane
separation element is shown in Figure 1a. The feed flow passes over a spacer element
designed to maintain an open channel while also promoting mixing in flow. The
resulting flow, which determines the solute distribution and hence membrane performance
is complex, three dimensional and unsteady. A typical membrane is also asymmetric
and is supported on the permeate side by a much finer spacer element, the details of
which are often overlooked. While these modules are successfully employed in many
industries, they must be reconsidered for use in salt power by pressure retarded osmosis
(PRO).
In salt power, a fresh water stream and a saltwater stream are introduced on ether side of
the membrane, while the fresh water permeates the membrane to dilute the saltwater
while increasing the pressure. The main differences between PRO and separation is that
the flow rates on each side of the membrane are different, and that the impact of small
amounts of salt permeating to the fresh water is much more severe. Accordingly, this
paper presents detailed numerical and experimental investigation into the physics of flow
and mass transport in such channels. Particle Imaging Velocimetry measurements are
compared with detailed Direct Numerical Simulation using the open source CFD software,
OpenFOAM. The results are critically discussed with a view to improving membrane
module designs for specific application to salt power.
a)
b) c) d)
Figure 1 – a) Spiral wound membrane element, b) computational domain c) comparison
of numerical and experimental results d) instantaneous velocity around the spacer elements.
Renewable Energy Research Conference 2010 175

The Centre for Renewable Energy
NTNU - SINTEF - IFE
Membranes for pressure retarded osmosis power plants
Torleif Holt 1 (Torleif.Holt@sintef.no)
Edvard Sivertsen 2 (Edvard.Sivertsen@sintef.no)
Willy Thelin 2 (Willy.Thelin@sintef.no)
1 SINTEF Petroleum Research, Seismic and Reservoir Technology, NO-7465 Trondheim, Norway
2 SINTEF Building and Infrastructure, Water and Environment, NO-7465 Trondheim, Norway
Pressure retarded osmosis (PRO) is one of the technical feasible processes which can be
used to extract some of the energy of mixing which is otherwise lost when fresh water is
mixed with sea water outside river mouths.
Effective utilisation of mixing energy by PRO requires membranes with additional
qualities as compared to available commercial reverse osmosis (RO) membranes. The
best present membranes for RO have the desired high water permeability (A) and low salt
permeability (B) that is required for efficient power production PRO. However, the rigid
support structures of RO membranes make them unsuitable for PRO as the effective
diffusion length in the support structures (the structure parameter, S) are to large.
The importance of the three parameters A, B and S for the efficiency of osmotic
processes will be discussed by the use of a transport model that includes concentration
polarisation on the membrane surfaces. The validity of the model will be substantiated
through modelling of laboratory experiments done with both cellulose acetate and thin
film composite membranes.
By use of the transport model it will be shown which values of the parameters A, B and S
that correspond to given values for the specific power (W/m 2 ) for fresh water/sea water
PRO. The importance of a low value of S will be emphasised.
Results from laboratory testing of commercial and development membranes in osmosis
and PRO modes will be presented. Examples of the performance of both flat sheet and
fibre membranes will be given. For several membranes the observed performance was
low and this was often related to large values of the structure parameter.
The use of flat sheet membranes requires the use of spacers to separate the membrane
sheets and to form the transport channels in the membrane module. Compression of the
support structure and blockage of diffusion paths in a pressurised module are other
factors that may impair the performance of a membrane in PRO. The presence of these
phenomena and their linkage to the mentioned factors will be discussed. The
requirements for a support structure suitable for PRO membranes will finally be
summarised.
Senterforfornybarenergi
Side1av1
Renewable Energy Research Conference 2010 176

The Centre for Renewable Energy
NTNU - SINTEF - IFE
Thin film composite polyamide membranes on a hydrophilic
celluloce acetate support for pressure retarded osmosis
Inger Lise Alsvik, Tom-Nils Nilsen, May-Britt Hägg
Department of Chemical Engineering, NTNU, Trondheim Norway
Pressure retarded osmosis (PRO) is an osmotically driven process and the driving force is not
an applied hydraulic pressure, but a transmembrane osmotic pressure. The pressure created in
PRO may be used for power production. In the past four decades membranes for reverse
osmosis (RO) are designed in order to desalinate water, which means the opposite process of
PRO. The transport properties of the best RO membranes could be sufficient also for PRO,
but due to water transport through the membrane from the support side in PRO, fouling is a
more important issue in this process than in RO. Concentration polarisation will also be
significantly higher. Both these effects will reduce the power production from an osmotic
power plant (OPP). More over, in RO the water first permeates the active layer by a solution
diffusion mechanism and then simply percolates trough the pores of the support layer. This
means that the porous support layer does not need to be fully wetted to ensure adequate water
flux. However, in an osmotically driven membrane process the support layer must fully wet to
ensure adequate permeate water flux.Vapor or air trapped in the pores blocks the passage of
water trough the support layer. Reduced continuity of the water within the layer may
exacerbate internal concentration polarization and reduce effective porosity resulting in a less
effective membrane in an OPP process [1-2]. Conventional seawater RO membranes are not
suitable for use in PRO due to their hydrophobic and thick support layer, the hydrophobic
interface between the two layers, the increased concentration polarization and increased
tendency to fouling in PRO. Membranes commonly used in osmotic processes are either
asymmetric cellulose acetate (CA) membranes or thin film composite membranes (TFC). TFC
membranes are designed with a thin (30 – 50 nm) separation membrane on top of a support
membrane. Asymetric CA membranes have been reported to performe better in forward
osmosis than TFC membranes with the less hydrophilic polysulfone support. TFC membranes
are however seen as the most promising membranes in PRO [3]. Preparation of membranes by
interfacial polymerization (IP) of polyamides (PA) on cellulose supports (more hydrophilic
than CA) has been proven to be difficult. By surface treatment of cellulose support
membranes we have successfully prepared continuous thin films by IP on this hydrophilic
support membrane. The water flux and salt rejection of the TFC membranes were determined
by reverse osmosis and the water flux obtained was 2*10 -12 m 3 /m 2 Pa*s and the salt rejection
98%. The membrane was tested at differential pressures up to 13 bars. The morphology of the
surface was examined by scanning electron microscope (SEM), atomic force microscope
(AFM).
1. McCutcheon, J.R. and M. Elimelech, Influence of membrane support layer
hydrophobicity on water flux in osmotically driven membrane processes. Journal of
Membrane Science, 2008. 318(1-2): p. 458-466.
2. McCutcheon, J.R. and M. Elimelech, Influence of concentrative and dilutive internal
concentration polarization on flux behavior in forward osmosis. Journal of Membrane
Science, 2006. 284(1-2): p. 237-247.
3. Gerstandt, K., et al., Membrane processes in energy supply for an osmotic power
plant. Desalination, 2008. 224(1-3): p. 64-70.
Renewable Energy Research Conference 2010 177

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CaCO 3 scaling in pressure retarded osmosis
Willy Thelin 1 (Willy.Thelin@sintef.no)
Torleif Holt 2 (Torleif.Holt@sintef.no)
Edvard Sivertsen 1 (Edvard.Sivertsen@sintef.no)
1 SINTEF Building and Infrastructure, Water and Environment, NO-7465 Trondheim, Norway
2 SINTEF Petroleum Research, Seismic and Reservoir Technology, NO-7465 Trondheim, Norway
Osmotic power is a renewable energy source exploiting the energy of mixing between
freshwater and seawater. Pressure retarded osmosis (PRO) is one of the methods that is
technically feasible to extract this energy. In PRO, freshwater and seawater are separated
by a semi permeable membrane that ideally only will allow transport of water, whereas
salts and dissolved constituents will be retained by the membrane. Due to the difference
in osmotic pressure across the membrane, there will be an osmotic transport of water
from the freshwater side to the seawater side of the membrane. The osmotic transport of
water will take place against a pressure gradient equal to approximately half the osmotic
pressure between the two solutions. The resulting net volume increase on the seawater
side will be utilised to drive a turbine.
One of the major challenges towards realisation of osmotic power as a commercially
feasible renewable energy source will be to maintain stable performance of the PRO
membranes over time. In this respect the control of membrane fouling and scaling will be
essential. Both adequate pre-treatment, in order to reduce the fouling potential of
incoming feed waters, and operation and maintenance aspects such as flux control,
disinfection and suitable membrane cleaning procedures will be important.
A study investigating the CaCO 3 scaling potential in PRO has been accomplished.
Laboratory experiments with model solutions having different saturation index (SI) with
respect to CaCO 3 have been performed, and the flux decline over time due to
precipitation of CaCO 3 scale was monitored.
A transport model estimating the concentration of Ca 2+ 2-
and CO 3 at the membrane
surface was developed and used to determine the SI for each of the experiments. Further,
the SI of CaCO 3 for a selection of 32 Norwegian rivers were calculated and for all cases
the SI at the membrane surface was simulated for operation in PRO.
Senterforfornybarenergi
Side1av1
Renewable Energy Research Conference 2010 178

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Design of an osmotic power plant
Edvard Sivertsen 1 (Edvard.Sivertsen@sintef.no)
Torleif Holt 2 (Torleif.Holt@sintef.no)
Willy Thelin 1 (Willy.Thelin@sintef.no)
1 SINTEF Building and Infrastructure, Water and Environment, NO-7465 Trondheim, Norway
2 SINTEF Petroleum Research, Seismic and Reservoir Technology, NO-7465 Trondheim, Norway
Osmotic power is a renewable energy resource with a significant potential world-wide
that has drawn increasing attention in recent years. The principle is to exploit the entropy
of mixing when mixing fresh water with sea water. Pressure retarded osmosis (PRO) is
one of the technically feasible processes which can be utilised to extract this energy.
In PRO freshwater and sea water are separated by a semi permeable membrane which
ideally allows only water to be transported through the membrane. The transport of water
through the membrane is caused by the difference in osmotic pressure, and the net
volume increase on the sea water side due to mass transport against a pressure gradient
can run a turbine.
The energy of mixing will be low compared to the volumes involved, giving challenges
in selecting suitable pre-treatment for the feed water. The specific power, i.e. power per
square meter of membrane, will also be relatively low, resulting in PRO power plants
with a large membrane area and consequently a significant number of membrane
modules, connections and distribution pipes. Controlling and reducing the hydraulic
losses in the power plant to a minimum thus become important.
The presentation will address the most important components in a PRO power plant, i.e.
membrane module, energy recovery device as well as the pre-treatment stage, and discuss
their interaction and impact on the overall plant efficiency. Further, some critical areas of
development for future PRO sucsess will be emphasised.
Senterforfornybarenergi
Side1av1
Renewable Energy Research Conference 2010 179

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NTNU - SINTEF - IFE
Reverse Electrodialysis – a Renewable DC Power Source
Odne S. Burheim a , Jon G. Pharoah b , Signe Kjelstrup a,*
a Department of Chemistry, Norwegian University of Science and Technology, NO7491
Trondheim
b Department of Mechanical and Materials Engineering,Queens University, Kingston,
Ontario, Canada K7L 3N6
* Corresponding author: signe.kjelstrup@chem.ntnu.no, tel: +47 73594179
We propose the reverse electrodialysis renewable electric power source (RED)
as an alternative to the pressure retarded osmosis power plant (PRO). Having
similar theoretical energy potentials, the two technologies are complimentary for
different markets as they deliver DC and AC electric power, respectively. As the
RED technology is less known we aim to give a brief introduction and present the
state of the art within this area. The reported electric power out put in the
literature is currently at 1/4 th of what we believe is achievable. We shall also
explain the path chosen for the further development on this technology.
Senterforfornybarenergi
Side1av1
Renewable Energy Research Conference 2010 180

The Centre for Renewable Energy
NTNU - SINTEF - IFE
Design of a reference tidal turbine
Céline Faudot (celine.faudot@ntnu.no)
NTNU: Energy and Process Engineering department
Mankind’s energy consumption is increasing every year and to reduce the greenhouse
effect, we need to develop new renewable energy devices. Thanks to their predictability
and their huge potential, tides are an interesting resource. It explains the appearance of
many tidal turbine designs, all of them are at a more or less early stage of development.
But because of the high density of water the environmental drag forces are very large
compared with wind turbines of the same capacity.
The aim of the project presented here is to create a 1 MW reference tidal turbine, whose
small-scaled model will be tested in the towing tank of MARINTEK (Trondheim) and
subjected to wave-current interaction. This research is carried out as part of the Statkraft
Ocean Energy Research Program. The chosen turbine has a horizontal axis and two
blades, which have been designed using the blade element momentum theory. The tests
will focus on the fatigue load due to the waves, which is an important reason of failure,
and thus will help tidal turbine designers in their work.
The investigation of the dynamic effects of the flow on the blades and the fatigue
phenomenon will permit to create a unique experimental database for validation of
numerical approaches for horizontal-axis tidal turbines located on wave exposed tidal
turbine sites. The data will be conducted at a relative large scale, improving accuracy of
distributed loads on turbine blades compared with existing data in literature.
The database will then be available on the Internet and freely usable by everyone who
wants to design a tidal turbine.
Renewable Energy Research Conference 2010 181

The Centre for Renewable Energy
NTNU - SINTEF - IFE
Dynamic Analysis of a Wave-Energy Power Generation
System Connected to a Distribution System through Power-
Electronics Converters
Li Wang a (liwang@mail.ncku.edu.tw),
Zan-Jia Chen a (zanjiancku@gmail.com)
a Department of Electrical Engineering, National Cheng Kung University, Taiwan
This paper presents the dynamic analyzed results of a wave-energy power generation
system connected to a distribution system through a rectifier, an inverter, and a
connection line. The studied wave-energy power generation system consists of an
induction generator (IG) driven by a Wells turbine through a gearbox (GB). Figure 1
shows the one-line diagram of the studied system. The complete dynamic equations of
the studied system under three-phase balanced loading conditions are properly derived
using a d-q axis reference frame. A time-domain scheme based on nonlinear-model
simulations is carried out to determine the dynamic behaviours of the studied system
under various disturbance conditions. Figure 2 shows the dynamic response of the active
power of the IG of the studied system when the velocity of air of the Wells turbine is
randomly varied. It can be concluded from the simulation results that the studied waveenergy
power generation system subject to different disturbance conditions can maintain
stable operation.
Figure 1 – One-line diagram of the studied wave energy power generation system
connected to a distribution system through a rectifier and an inverter
1.2
P i g ( p. u. )
0.8
0.4
0.0
-0.4
0 20 40 60 80 100
t (s)
Figure 2 – Dynamic response of the generated active power of the IG of the studied
system when the velocity of air of the Wells turbine is randomly varied
Renewable Energy Research Conference 2010 182

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On Design and Performance Prediction of Horizontal Water
Turbine
Ming-huei Yu a (mhyu@mail.nsysu.edu.tw),
Hsing-nan Wu a (shingnanwu@so-net.net.tw),
Wen-yi Li a (m953020046@student.nsysu.edu.tw)
a National Sun Yet-sen University, Kaohsiung, Taiwan
The ocean accounts for at least two thirds of the earth’s surface, the potential energy of
which is now regarded as one of the most significant renewable energies nowadays.
Taiwan is surrounded by sea. Along its east coast the Kuroshio passes at the current
velocity in the range of 1 to 2 m/sec. In some Taiwan areas like the Pescadores
Archipelago, the velocity can reach up to 2 m/sec or more. Motivated by the future
development of ocean current energy, the study aims to design a horizontal water turbine
and evaluate its performance before the fabrication. In designing the water turbine, an
ideal airfoil with high lift-to-drag ratio is chosen as the cross-sectional profile of turbine
blades. With the profile, the chord length and pitch angle of the turbine blades along the
radial direction are determined by applying blade element momentum theory. The
velocity and pressure fields around the designed turbine are simulated by computational
fluid dynamics. The torque and power of the water turbine are then evaluated at various
rotational speeds, which are important data for further generator design to produce
electrical power. Influences of blade radius, blade number and free stream velocity on the
turbine performance are investigated in this study. It is shown that the torque and power
of the turbine increase with large blade radius. The turbine output power is approximately
proportional to the square of the blade radius. The numerical simulation also shows that
the maximum turbine power will be approximately 8 times if the free stream speed is
doubled. A turbine with more blades will produce more output power. However, the
power increment from 3-blade turbines to 4-blade turbines is less significant than the
power increment from 2-blade turbines to 3-blade turbines. Thus, a 3-blade turbine is
considered more ideal in terms of turbine design. To validate the numerical simulation for
further turbine design, a 3-blade turbine was fabricated and tested in a water channel.
The experimental data are compared with the numerical results. Although some
discrepancy occurs between the simulation and in-situ experiments, a similar trend can be
observed in both simulation and experiment results.
Renewable Energy Research Conference 2010 183

The Centre for Renewable Energy
NTNU - SINTEF - IFE
A Novel Approach for Extracting Ocean Wave Energy
Utilizing the Wave Shoaling Phenomenon
Shafiq R. Qureshia (shafiqpn1@alumni.manchester.ac.uk), Syed Noman
Danish b (snoman@pnec.edu.pk) and M Saeed Khalid c
(khalidm@pnec.edu.pk)
a,b,c National University of Sciences and Technology (NUST),Pakistan
Fossil fuels are the major source to meet the world energy requirements but its rapidly
diminishing rate and adverse effects on our ecological system are of major concern.
Renewable energy utilization is the need of time to meet the future challenges. Ocean
energy is the one of these promising energy resources. Three-fourths of the earth’s
surface is covered by the oceans. This enormous energy resource is contained in the
oceans’ waters, the air above the oceans, and the land beneath them. The renewable
energy source of ocean mainly is contained in waves, ocean current and offshore solar
energy. Very fewer efforts have been made to harness this reliable and predictable
resource. Harnessing of ocean energy needs detail knowledge of underlying mathematical
governing equation and their analysis. With the advent of extra ordinary computational
resources it is now possible to predict the wave climatology in lab simulation. Several
techniques have been developed mostly stem from numerical analysis of Navier Stokes
equations. This paper presents a brief over view of such mathematical model and tools to
understand and analyze the wave climatology. Models of 1 st , 2 nd and 3 rd generations have
been developed to estimate the wave characteristics to assess the power potential. A brief
overview of available wave energy technologies is also given. A novel concept of onshore
wave energy extraction method is also presented at the end. The concept is based
upon total energy conservation, where energy of wave is transferred to the flexible
converter to increase its kinetic energy. Squeezing action by the external pressure on the
converter body results in increase velocities at discharge section. High velocity head then
can be used for energy storage or for direct utility of power generation. This converter
utilizes the both potential and kinetic energy of the waves and designed for on-shore or
near-shore application. Increased wave height at the shore due to shoaling effects
increases the potential energy of the waves which is converted to renewable energy.
This approach will result in economic wave energy converter due to near shore
installation and more dense waves due to shoaling. Method will be more efficient because
of tapping both potential and kinetic energy of the waves.
Renewable Energy Research Conference 2010 184

The Centre for Renewable Energy
NTNU - SINTEF - IFE
Dynamic Analysis of a Grid-Connected Marine-Current Power
Generation System Using an Induction Generator
Li Wang a (liwang@mail.ncku.edu.tw),
Jian-Hong Liu a (jianhongncku@gmail.com)
a Department of Electrical Engineering, National Cheng Kung University, Taiwan
This paper presents the dynamic analyzed results of a grid-connected marine-current
power generation system using an induction generator (IG) that is driven by a marinecurrent
turbine though a gearbox. Figure 1 shows the one-line diagram of the studied
grid-connected marine-current power generation system. The complete dynamic
equations of the studied system under three-phase balanced loading conditions are
properly derived using a d-q axis reference frame. A time-domain scheme based on
nonlinear-model simulations is carried out to determine the dynamic behaviours of the
studied marine-current power generation system under various disturbance conditions.
Figure 2 shows the dynamic responses of the marine current speed and the generated
active power of the IG of the studied marine-current power generation system when the
marine-current speed is randomly varied. It can be concluded from the simulation results
that the studied marine-current power generation system subject to different disturbance
conditions can maintain stable operation.
GB
IG
R T
X T
C
Grid
Figure 1 – One-line diagram of the studied GCIG-based grid-connected marine-current
power generation system
3.5
3
0.7
0.6
2.5
0.5
U 0
(m/s)
2
1.5
p ig
(p.u.)
0.4
0.3
1
0.2
0.5
0.1
0
0 2 4 6 8 10
t (hr)
0
0 2 4 6 8 10
t (hr)
Figure 2 – Dynamic responses of the marine-current speed (left) and the generated active
power of the IG (right) of the studied system under time-varying marine-current speeds
Renewable Energy Research Conference 2010 185

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NTNU - SINTEF - IFE
Control Strategies of a Wave Energy Converter for Power Quality Improvement
E. Tedeschi * , P.Ricci ** , M. Santos ** , M. Molinas * , J.L.Martin ***
[elisabetta.tedeschi,marta.molinas]@elkraft.ntnu.no,[pricci,msantos]@robotiker.es,
joseluis.martin@ehu.es
* Norwegian University of Science and Technology
** Fundacion Robotiker- Tecnalia/RBTK Energia
***
University of the Basque Country
Despite the increasing attention paid to Wave Energy Converters (WECs), a single
leading technology has not yet been established. One of the most promising concepts is
that of point absorbers, which have been extensively studied in the past decades, with
special focus on control strategies. In order to achieve commercially viable solutions,
however, it is now mandatory to consider the impact of the different control techniques
on the overall power conversion process, taking into account also the possible limitations
arising from the Power Take-Off (PTO) rating and the grid connection requirements.
In this paper such aspects are addressed referring to a two-body system (fig. 1), due to the
possible advantages that it shows when compared to simple floating buoys in terms of
reduced infrastructural costs and ease of implementation in deep waters.
At first an insight of the system behaviour is provided and a corresponding simplified
model is addressed. Following, under the assumption of monochromatic incident waves
and linear Power Take-Off, a frequency domain analysis is carried out, as a sort of
reference best case to be considered in the system design. In regular waves the condition
of maximum average power extraction, corresponding to complex-conjugate control, is
well known and consequently the power performance of the system can be exactly
quantified.
In order to assess the real power extraction of the specific WEC, however, the analysis of
its behaviour in irregular waves is required. In fact it is shown that, when tested in
irregular waves the power performance of the selected device may be extremely degraded
compared to the theoretical case and the advantage of complex-conjugate control with
respect to traditional passive loading is not apparent anymore. An additional goal of the
analysis in irregular waves is to highlight some of the critical points of wave energy
conversion that are related to the intrinsic extreme variability of the instantaneous power.
The presence of very high and sporadic peaks is a severe problem, since it requires a
consistent over-rating of the electric generator and the power electronics converters and it
has significant impact on energy storage needs. Thus the practical design of the Power
Take-Off results in a limitation to the power that can be handled by the system. As a
consequence, the elaboration of an optimised control technique allowing the maximum
power extraction under this new constraint is priority.
A discrete control strategy, acting when the instantaneous power exceeds a defined
threshold, is here proposed and its impact on both the average power extraction and the
reduction of power variability is discussed.
In the considered test case, the optimisation of such control approach is also investigated
through numerical simulations and the procedure is tested in different sea states, in order
to draw some general conclusions.
Renewable Energy Research Conference 2010 186

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As a consequence of this optimised control approach, the relevant considerations about
the sizing and design of a direct-coupled electrical machine and of the power electronics
that is needed for both the implementation of the proposed control and the grid
interconnection of the WEC are finally discussed.
Renewable Energy Research Conference 2010 187

The Centre for Renewable Energy
NTNU - SINTEF - IFE
Tuned liquid tank used to suppress motion of a floating wave energy capture system
Bang-Fuh Chen* and Shih-ming Huang
Department of Marine Environment and Engineering
National Sun Yat-sen University Kaohsiung, Taiwan 804
*: chenbf@mail.nsysu.edu.tw
One of the ocean current energy capture systems might be mounted on a floating
barge if the sea depth is large. The dynamic response of the floating barge will be
affected the efficiency of the energy capture as the current passing turbine. The tuned
liquid damper can be used to suppress horizontal and vertical motions of a structure. A
time-independent finite difference method was used to solve for the fully nonlinear
sloshing fluid in a tank which is mounted on a structure. The interaction between sloshing
fluid and dynamic response of the structure is studied. The numerical model is validated
by several rigorous data comparisons. The tank is tuned to a proper depth to length ratio
(d0/b) and acts as a tuned-liquid damper. Several examples were studied including large
and small structures. The vibration control is tested in terms of reduction of dynamic
response of the structure and also the reduction of the maximum energy development in
the tank-structure system during excitation.
For a large structure, the proper selection of water depth in tank can significantly
reduce the dynamic displacement of the tank-structure system. While improper water
depth selection would even enhance the dynamic response of the structure. For a small
structure, the numerical results show the energy developed in the system is close related
to both the dynamic displacement of the structure and the sloshing displacement of fluid
in the tank. A fluid filled tank with water depth = 0.5 b is used in this case and the
maximum energy developed in the tank-structure system is only one-tenth of that of a
structure without tank mounted. The tuned-liquid-tank also can be used in the vibration
control of a small structure.
Renewable Energy Research Conference 2010 188

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NTNU - SINTEF - IFE
ABSTRACTS
Social Studies of Renewable Energy
Renewable Energy Research Conference 2010 189

The Centre for Renewable Energy
NTNU - SINTEF - IFE
E1: Public acceptance, understanding of renewable energy
technologies
Public engagement in wind energy: Lessons from a Dutch case
study
Suzanne Brunsting, PhD, brunsting@ecn.nl (correspondence please to first author)
Sylvia Breukers, PhD, Ruth Mourik, PhD, Thomas Mikunda, MSc
Energy Research Centre of the Netherlands
Department ECN Policy Studies
http://www.ecn.nl/ps/
Summary
Although research on public attitudes towards wind power in Europe indicates that the public
generally approves of wind energy since the technology was first widely introduced in the
1980’s, gaining local support for wind projects remains difficult. One way of increasing
public support is public involvement. Indeed, in the Netherlands there are some successful
examples of co-ownership in onshore wind farms. However, this is by itself no guarantee for
success.
This paper describes a case study of a wind farm in the North-West of the Netherlands, owned
by a wind cooperative, which offered community members the opportunity to become a
shareholder. Nevertheless, the project faced strong protest from the local community, which
severely delayed the project. Moreover, the protest continues to thwart the cooperative’s
future plans in the region. It is therefore imperative to investigate the causes of public protest,
which is the aim of this study.
Data collection was done by (1) extensive desk research of publicly available project
information, (2) obtaining missing and confidential information from stakeholders, and (3)
conducting six in-depth interviews with representatives of the key stakeholder groups
involved. The paper provides a detailed description of the project features, a chronology of
events, and the legal, policy, and public perception context in which the project is embedded.
We identify main public concerns and relate them to developments in the project.
Furthermore, we map all stakeholder communication activities and the communication media
and materials they used, we analyze local media coverage, and we analyze the development of
stakeholders’ views on the project and on each other. The paper ends with conclusions on the
development of public protest and describes implications and recommendations for public
involvement in future wind projects as well as in other renewable energy projects.
Renewable Energy Research Conference 2010 190

The Centre for Renewable Energy
NTNU - SINTEF - IFE
Image is everything? On Norwegian and Swedish representations of
bioenergy
Tomas Moe Skjølsvold, tomas.skjolsvold@ntnu.no
Abstract
Gaining social acceptance for new renewable energy technologies is a crucial step on the path
towards low-carbon societies. In Norway this is perhaps most clearly observed in numerous
controversies surrounding on-shore wind-power. A recent survey (Karlstrøm 2010) shows that
on-shore wind-power along with bioenergy are the two least popular renewable energy
technologies in the Norwegian public.
This paper deals with the “image” of bioenergy, comparing the situation in Norway and
Sweden. Bioenergy currently represents around 6 % of Norway’s energy consumption (most
of this being traditional firewood), while the Swedish figure is around 30 %. Many actors in
the Norwegian bioenergy industry despair over what they perceive as a knowledge deficit
regarding their products. This knowledge deficit, they claim, is one of the main non-technical
barriers keeping the industry from gaining larger shares of relevant markets. In practical terms
the result is that potential customers see their products as “dirty”, “low quality”, “high
maintenance”, “smelly”, “spacious”, or as a hazard to the environment. The Swedish
experience represents an interesting counter example. Here, the bioenergy industry has market
shares the Norwegians can only dream about, but the industry is still upset about a public
knowledge deficit. The problem is, however, of a different kind than in Norway. A recently
published survey (Svebio 2010) shows that the Swedish public is largely unaware of the
success achieved by bioenergy in Sweden. In other words; in Sweden where its use is
widespread bioenergy is “invisible”, but in Norway where it is hardly used it is perceived as
something which might bring negative consequences. This paper explores this apparent
paradox based on qualitative data from the two countries.
Renewable Energy Research Conference 2010 191

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Approaching public acceptance of new technologies by
studying the subjectivity: the hydrogen case.
Olga Di Ruggeroa (o.diruggero@tudelft.nl),
Alexander R.C. de Haana (a.r.c.dehaan@tudelft.nl)
Delft University of Technology
By presenting the case of Hydrogen we aim to propose and discuss a new approach to
thestudy of public acceptance of new technologies.
Hydrogen is a promising but also very controversial technology, thought as part of a
long-term solution for many issues related to energy, like air pollution, greenhouse gas
emissions, energy security, oil independency or the unreliability of renewable sources
(that are intermittent sources of energy) when hydrogen is used as a storage tool.
Unlike the majority of previous acceptance studies, which focused mainly on safety and costs,
we study acceptance by relating the specific technology to the issue that it is meant to
contribute to. Hydrogen can be produced, stored, distributed and used in very different ways,
which might be beneficial for some issues but at the detriment of other ones. For example, the
use of hydrogen-fuel cell cars can reduce emissions at the local level, but increase greenhouse
gas emissions if hydrogen is produced through fossil fuels. In a case like this,
acceptance conflicts might arise, for instance, between a societal party prioritizing climate
change issues, and a second party interested in the reduction of health threats. Different
people within the public will distribute their support between these two parties according with
their degree of agreement with the party’s beliefs (i.e. their importance of reducing urban
pollution vs. climate change), or even reorganize in a new party if their own beliefs are not
represented in the public debate. Similar conflicts might arise if other primary energy sources
are used in hydrogen production, such windmills, nuclear or biomass.
Other than previously published studies, we adopt a theoretical framework, the Value-
Beliefs-Norms of Stern as a key to describe and understand acceptance issues as the above
mentioned example. Guided by this framework, we aim to: 1) identify the beliefs behind
acceptance, where the beliefs represent the issue that should have to be solved and the
attribution of responsibilities on who should take an action in response to that issue;
2) identify how these beliefs are organized in belief systems, namely identify a particular
combination of beliefs which represents the perspective of each party 3) verify if and where
these belief systems are conflicting.
To achieve our goal we will use a conventional tool in network analysis: the
methodology, which identifies qualitatively the perspective of the single actors and
quantitatively relates these “segments of subjectivity”. Our challenge is to extend the use of
this conventional tool to “the public” which, unlike the majority of previous studies, is not
considered by us as an external factor nor as an indistinct mass. One of the principal aim of
our study is thus to relate the different perspectives of the people within the public with the
variety of perspectives of the institutional actors (i.e. policy makers and NGOs).
Renewable Energy Research Conference 2010 192

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NTNU - SINTEF - IFE
Brøset - carbon neutral settlements in the making
PhD Helen Jøsok Gansmo
STS, NTNU
7491 Trondheim
Helen.gansmo@hf.ntnu.no
In order to achieve the Norwegian Government’s goal of making Norway a carbon neutral
nation within 2030 we must be able to construct local carbon neutral settlements within a few
years. In Trondheim the local authorities selected the area Brøset to be developed as “a
sustainable neighbourhood”. “Sustainable” is defined in a holistic way, including low energy
demand and healthy materials as well as social and economic issues such as low cost housing
for vulnerable groups.
The municipality is in charge of the planning process of Brøset in cooperation with
governmental institutions and an interdisciplinary group of researchers at NTNU and
SINTEF. Planning and designing a carbon neutral settlement is not only a matter of
innovative technology and material and energy development and use, but includes for instance
lifestyle, housing patterns, transportation and leisure-related travel for the residents. The aim
is to make Brøset a neighbourhood where residents can live, work, shop, go to school and find
meaningful leisure activities in settlements which enable people to lower their “carbon
footprint”.
This paper will address how the planners try to meet the desires of diverse future residents as
well as getting renewable energy and sustainable solutions integrated into the area. What
sociotechnical actors and solutions are regarded as (un)controversial in the process? And what
mediating actors do/could contribute in building alliances towards planning, building and
living in carbon neutral settlements?
Renewable Energy Research Conference 2010 193

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Mass Media and Renewable Energy representation by societies:
A wind farm project in Puerto-Rico
Judith Priam a (priamjud@gmail.com),
Dr. Neftalí García Martínez b (nefgama@yahoo.com)
a Université des Antilles et de la Guyane –Centre d’Analyse Géopolitique et Internationale-,
and Servicios Científicos y Técnicos
b Servicios Científicos y Técnicos
In the presentation we want to underline the role of mass media, particularly the press, in the
construction of the representation of an issue. We discuss the case of a wind farm project on
the island of Puerto-Rico.
We evaluated the environmental impact documents prepared for the project and participated
in public hearings where opposing views were presented regarding the impact of the project
on the social and natural milieu.
We have worked on a comparison of media information, stakeholders’ opinions and scientific
information obtained from different sources.
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Norway: Some lessons from a international project on CCS communication
Authors:
Hans Torvatn, SINTEF
Sturle D. Tvedt, NTNU
Robert Næss, NTNU
Carbon Capture and Storage (CCS) has been part of the Norwegian debate on energy and possible
solutions to the climate problems for more than a decade. One prime ministers fell from power on
this issue, another first promised a “Norwegian moon landing”, then postponed the whole thing for
several years. The debate has been heated several times, but little is known about what the public
knows and thinks.
The present paper presents some findings from six national surveys on knowledge and attitudes on
CCS as part of the FENCO-ERA project “Scrutinizing the impact of CCS communication on the general
and local public (Impact of communication)”.
Representative national surveys (N=6*1000) were conducted in six European countries: Germany,
Greece, the Netherlands, Norway, Romania and the UK.
Main topics covered: Sociodemographics, Attitudes towards energy issues, Media preferences, Trust,
Knowledge on global warming and energy issues including CCS, initial attitudes towards CCS. The
surveys also included an information experiment, testing the effect of positive and negative
information on general acceptance of CCS. The paper will focus on the results from Norway using the
other countries as illuminating contrasts.
In Norway we will discuss four major findings:
i) The majority of the Norwegian population are aware of CCS
ii) There is a positive support for CCS demonstration plant, however, the support is
unevenly distributed in the population
iii) Information on CCS effects attitudes, however, source is less important than content
iv) The project asked respondents to evaluate both risks and benefits. In Norway the effect
of the benefit evaluation was stronger than the risk evaluation.
Implications for CCS communication with the public as well as future research are discussed.
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User participation in future carbon-neutral settlements
Erica Løöfstrøm, NTNU erica.lofstrom@ntnu.no
It is generally acknowledged that end-users are an important factor in the creation and maintenance
of a long-term sustainable resource use. How and when resources are consumed obviously
determines the ability to create long-term sustainable systems. Users are also ultimately the ones
who profit or suffer from the successful or failing transformation of socio-technical systems, which
increases their importance as a key component of the system.
Taking on the challenge of global warming, carbon-neutral settlements, low-energy dwellings and
sustainable land- and water use become key issues. To develop sustainable energy systems, users
need to transform their behavior and start reflecting on their energy use. The aim with this paper is
to discuss different methods to achieve and maintain user participation in the building of new
residential areas with ambitious goals for environmental sustainability. Every method has its
drawbacks, but combining different energy- and resource visualizing methods could be one way to
highlight households’ energy use and their possibility to energy conservation. By using the results
from the introduction of such methods when developing information campaigns and in energy
guidance, as well as including energy- and resource visualizing equipment in the building of carbon
neutral settlements, we can find strategies that appeal more closely to peoples’ behavior, hence
making it easier for households to put the advice into practice in their everyday lives.
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E2: The renewable energy innovation system: innovation
and learning
User innovation, social learning and renewable energy technology:
Lessons from Austria
Michael Ornetzeder (ornetz@oeaw.ac.at)
Institute of Technology Assessment
Austrian Academy of Sciences
1030 Vienna, Strohgasse 45/5
tel. ++43 1 51581 6589
fax ++43 1 7109883
www.oeaw.ac.at/ita/
In Austria the diffusion of thermal solar technology has been highly successful in the last 20
years. Per capita, Austria is one of the countries the best equipped in solar systems in Europe
(on second place behind Cyprus). Moreover domestic producers of solar systems are market
leader in the EU. In 2008 one out of three solar systems sold in EU-27 came from Austria. In
my presentation I will show that the foundation for this remarkable situation was laid in the
first phase of the introduction of this technology in the early 1980s. User innovations and
social learning were of decisive importance in this phase. Early users were able to change not
only the technical design but also the way this technology was integrated into the building.
They redefined the mode of how and for what purpose it was used. And these early users
added an additional meaning to the “green” technology, as it was perceived in the beginning
by putting more emphasis on aspects of personal comfort. All in all early users were
responsible for some significant changes to the initial design of solar heater systems, which
contributed to a large extent to the incredible diffusion success of solar technology in general.
In the paper I will present main findings from the case study research and discuss conclusions
on a more general level.
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Developing Norwegian wind power – a case of “meeting ones former self”?
Ole Inge Gjerald, Vestlandsforskning/NTNU. E-mail: oig@vestforsk.no
Abstract
Norwegian wind conditions are among the best in Europe, and the interaction with
hydroelectric power is also a great advantage. Still, Denmark has 10 times as much wind
power as we do. Germany has more than 100 times as much. Today there are a number of
companies working on projects along several parts of the coast, but few of these projects are
just about to be realized. Why has it not been developed more wind power in Norway the
resent years?
The national government wants to focus more strongly on renewable energy,
environmentally friendly heating and more efficient energy use. One of the goals pointed out
is to make a contribution of 30 TWh per year by 2016. This is equivalent to ¼ of the total
Norwegian electricity production. There will be a need for substantial development of wind
power if this national goal should be reached.
This article addresses the strategic situation of Norwegian companies that engage in
innovation, implementation and commercialization of technologies for wind energy. It
analyzes how such companies are affected by current Norwegian energy- and industrial policy
and how they perceive their options to innovate, implement and commercialize renewable
technologies.
To illustrate the interaction between the companies and both local and national
authorities, we concentrate our focus on the licence application process for wind energy
companies. This process includes all the relevant actors that have to support the idea of
building a wind farm if it should be realized. How do the companies look at this process and
in what ways represents the process several formal obstacles on the road from a good business
idea to business realization? The title indicates that the government quite often is in conflict
with itself. Ambitious national goals do not always go well together with what the national
government’s representatives at the county level mean. For the energy companies this can be
quite confusing. These companies tell a story about a comprehensive licensing application
process which poses considerable challenges with respect to assembling sufficient support to
overcome these difficulties.
The article puts particular emphasis on the complex activities of assemblage that
industrial as well as local policy actors are involved in, drawing on Latour (2005). The article
is based on interviews with industrial actors and analysis of relevant governmental white
papers, plans and documents.
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Commercialisation of environmentally oriented consulting
engineering services
Jøran Solli (joran.solli@ntnu.no),
Norwegian University of Science and Technology
Arguably, the consulting engineering companies are involved in the construction of a market
for services with a focus on sustainability. The first and modest ambition with the paper is
finding out to what extent they actually are involved in such efforts and weather they see
these efforts as successful. Further, the paper set out to discuss how they perceive their
achievements with respect to the mediation (and implementation) of their environmentally
relevant knowledge to different groups of users, and what do they consider to be the key
facilitators and impediments of success? Consulting engineering companies often experience
pressure to provide cost-effective services. Does this lead to a dominance of pragmatic
approaches, like re-use and standardisation of knowledge products? Is there a lack of
incentives for innovation and efforts to keep abreast of new environmental knowledge?
In addressing these questions I want to explore flows of knowledge in and epistemic
machineries (Knorr Cetina 1999) of consulting engineering companies. This exploration is a
part of a larger research project focusing on the character and relative importance of the
sources of knowledge and information that the consultants draw from, including their
accumulated experiences. In particular, such an focus aim to provide a good understanding of
the accumulation of experience, how experience is managed and formalised, and how and to
what extent experience is shared among consultants within companies and within the wider
consulting industry. Have they established well-functioning communities of practice or
occupational communities (Lave & Wenger 1991, van Maanen & Barley 1984) that facilitate
accumulation and sharing of knowledge?
The empirical analysis is based on interviews in four Norwegian consulting firms, two large
and two small. We will focus on two main areas in which market services potentially are
developed; energy solutions in buildings and transport.
I believe knowledge on how commercialisation of environmentally oriented consulting
engineering services are developed and made will be useful to, in addition to the industry
itself, also to policy-makers who need a better understanding of the industry and how it may
be encouraged to improve its efforts towards a sustainable development. Scientific institutions
interacting with the industry may also benefit from such insights
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Markets as learning arenas for “new” renewable energy technologies?
Feed-in tariffs, learning and the technological innovation system for Solar
cells
Jens Hanson, Centre for technology, innovation and culture, University of Oslo
jens.hanson@tik.uio.no
The paper investigates the role of institutional change and policy linked to the emergence and
growth of innovation systems around new renewable energy technologies (RET). Most new
RET are characterised by low green house gas emissions but at the same time inferior
maturity and low competitive ability compared with dominating energy technologies. The
latter is the main bottleneck hampering rapid and widespread diffusion of RET. The core
question associated with all new RET is therefore not only how to increase the share of these
in the energy mix, but more importantly how their competitive ability may be strengthened.
Germany has raised its share of renewable energy drastically the last decades in spite of a
long withstanding lock-in around fossil fuels and nuclear power. The increase of RET in
Germany is largely due to introduction of the feed-in tariff (FIT). The FIT stimulates diffusion
of RET by providing incentives for investment through enabling the sale of electricity from
renewable sources onto the grid and receiving bonus payments. In the discussion on how
stimulation of RET diffusion is related to learning and emergence of new innovation systems
the paper poses a twofold question; How is the feed-in tariff policy designed to create new
markets for RET? To what extent and through what mechanisms do created and stimulated
markets lead to the emergence of new learning arenas for new renewable energy
technologies?
The initial observation in the paper is that the FIT functions as a driver towards (increased)
market introduction for RET. The paper discusses this as the creation of markets as learning
arenas for “new” renewable energy technologies. These learning arenas are argued to differ
from arenas created by R&D stimuli as well as other types of RET policy. The core difference
is active technological choice (i.e. selecting technologies and tariff levels), which upholds
technological heterogeneity, as well as stimulation of actual market introduction associated
with long-term stability giving rise to industry response. We use a case study of the solar
energy industry to illustrate how markets create new learning arenas. Due to markets
supported by FIT the solar cell industry has grown rapidly the last decades. A key insight of
the paper is that learning on the market has spurred industry dynamics by facilitating the
emergence of key system components such as dedicated raw-material producers as well as
specialised suppliers. The paper discusses this as a process of building technological
innovation systems, which in turn may be viewed as a way of unlocking existing
technological regimes (i.e. fossil fuel based energy systems).
The paper analyses the role of the FIT policy in the technological innovation system for solar
energy. In particular we look at how the FIT is designed on the basis of a learning curve
rationale. The paper finds that the FIT formally decouples industry and public institutions (by
supporting users not producers), yet the use of a learning curve rationale creates strong
interdependencies amongst policymakers and technology producers in practise (i.e. policy
relies on cost cuts from industry, and industry relies on tariffs to survive and grow). The paper
concludes with a discussion on how the weak links between institutions, policy design and
industry may pose long-term legitimacy problems, given that future development may not
follow trajectories lined out by policy.
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Operable Urban Landscapes: Investigations on Utilization of
Renewable Energy Sources in Urban Contexts
A.Senem Devirena (deviren@itu.edu.tr, asenemd@yahoo.com)
Istanbul Technical University
‘Energy efficient architecture’ is one of the movements offered to accelerate solutions to
prevent energy consumption and help to provide comfort with increased use of renewable
energy sources. There are several attempts and resources concentrated on how to implement
the practical knowledge and technology about the construction of energy efficient buildings.
There are also building directives developed for regions or countries to provide the rules
which are regulating conditions and defining limits for the practice. However, the rules and
regulations for the construction and renovation of energy efficient buildings are only
addressing the reduction in energy consumption and enhancement of energy performances
through use of technology with no reference to the site and the surrounding context of the
buildings. Although the directives are necessary, and even though applied, they fall short in
defining the contextual parameters to inform ecologically sustainable, energy efficient, social
and livable urban patterns. The critical task in urban design is to explore the ways to achieve
ecologically sustainable, comfortable, energy efficient, social and livable contexts without
extensive use of technology and resources. My proposal is that often neglected and
unconsidered spaces between the buildings - the in between spaces-, when considered as
living parts of the larger surrounding landscape, could contribute to the achievement of this
critical task; the main purpose should be to transform the neglected in between spaces into
multi potential landscapes. With the exception of planned and designed urban parks, squares
and streets, the character of the in between spaces occurring between largely anonymous, illproportioned,
randomly-built buildings in the urban contexts, are often spontaneous,
unplanned and unexpected in character. The size, location, position, spatial definition,
structure and materials constituting them vary greatly. Therefore the transformation of these
spaces into living/multi-functional landscapes requires a multi dimensional thinking and
design process in order to achieve the critical task of livable urban contexts and energy
efficiency with utilization of renewable energy sources and ecologically benign technologies.
This study is based on a research project I have completed –as the principal investigator- at
the Institute of Advanced Studies on Science, Technology and Society (IAS-STS), Graz, in
2009 that has been supported by Manfred Heindler Grant and Istanbul Technical University
Rectorate. The main purpose of the study is to investigate the role of the landscapes in
between for the utilization of renewable energy sources and the integration of architecture and
landscape as a potential field for inventions in urban design to help to complete our ecological
and social task.
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Biogas in Burkina Faso
Influential factors of biogas projects in rural areas of Burkina Faso
Andreas Aschaber (andreas.aschaber@uibk.ac.at)
University of Innsbruck, Department of Sociology, Austria
Burkina Faso is among the poorest countries in the world. The energy situation in Burkina
Faso is among the most critical issues which need to be addressed in the country. The
electrical power grid is insufficient and only available in urban centers. Consequently wood
and charcoal is used in order to meet the basic needs for heating, cooking, and lightning by
the majority of the population. The resulting overuse of natural energy resources in Burkina
Faso has been causing massive deforestation and desertification on the one hand and on the
other hand scarcity in fuel wood availability.
According to a recent feasibility study of the GTZ, biogas is thought to be one of the most
sustainable solutions for developing energy self sufficiency in rural areas of Burkina Faso.
Biogas is not a new concept in Burkina Faso, as the first biogas plants were already installed
in the 70’s. Recently a national biogas program and the activity of various NGOs lead to a
rejuvenation of attempts to establish biogas in Burkina Faso. Although biogas has a long
history in Burkina Faso, no significant breakthrough of this technology has happened so far.
None of the biogas plants built during the last 40 years have been operational for a long time.
This contribution presents a study aimed to analyze the partial success and failures of the
attempts to install biogas plants so far. The study was conducted in May 2009 as part of a
project for a model application of the technology in the frame of University cooperation
between Austria (University of Innsbruck) and Burkina Faso (Université Polytechnique du
Bobo Dioulasso).
During the field study four sites of existing biogas plants were visited, five interviews with
experts conducted and two focus groups with potential users in a rural setting were conducted.
The systemic approach, including technical as well as socioeconomic aspects, yielded a
wealth of factors which can potentially influence the success of biogas projects in rural areas
of Burkina Faso. The material was processed according to the content analyses of Mayring.
The study identified altogether 38 factors which were grouped into different categories -
socio-cultural, technology, economic, institutional, infrastructure, operational, substrate and
competitive energies. The results are thought to provide a sound base for better management
of future biogas projects in the rural area of Burkina Faso.
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New Renewable Electricity – A future Norwegian export industry?
Olav Wicken, Centre for technology, innovation and culture, Univeristy of Oslo
olav.wicken@tik.uio.no
The paper will discuss societal and economic challenges regarding development and use of new
energy resources for production of electricity. The point of departure is the availability of vast
potentital energy resources in Norway; from wind onshore and offshore, waves, tides, salt, in addition
to biomass, solar energy etc. In spite of the availablabilty of new renewable energy sources, very few
resources have been transformed into economic production.
The paper argues that Norway is locked into an energy system which creates small opportunities for
increased production of renewable electricity. The electricity production has always been based on
renewable energy (hydropower) and domesic production covers total domestic consumption. Increased
production implies the transformation of electricity into an export industry. The paper will argue that
this is not purely an economic process, but is a transformation of the meaning of electricity in the
Norwegian society. Electricity is transformed from being social infrastructure to a commercial activity
where the main role of the electricity industry is to increase exports earnings.
This makes Norway’s position different from neighbouring countries where renweable energy still has
an important role to play as infrastructure or as part of wider policy considerations. There are strong
drivers for increased production of renewable energy as climate policy (reduce emissions), energy
security (independence of import), industry policy (build up of technology sectors), regional policy
(employment in specific regions), etc. As new renewable electricity plays no similar role in the
Norwegian context, there is a lack of drivers domestically to expand the electricity sector. Following
this line, the paper argues that development of new renewable energy production is closely related to
public policy. How renewable energy productions emerge will depend on how business respond to
policy institutions both domestically and internationally.
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E3: Energy policy: Governance, commercialization and
industrial development
Fostering Renewable Energy in Small Developing Island States
Through Knowledge and Technology Transfer: the – DIREKT
Project
Prof. Walter Leal (BSc, PhD, DSc, DPhil, DL)
(walter.leal@haw-hamburg.de),
Veronika Schulte (veronika.schulte@haw-hamburg.de)
Julia Gottwald (julia.gottwald@haw-hamburg.de)
Hamburg University of Applied Sciences,
Research and Transfercentre ”Applications of Life Sciences”
Faculty of Life Sciences
It is widely acknowledged that the use of renewable energy may assist developing countries
as a whole and Small Island States in particular, in addressing their energy needs and at the
same time reducing their dependence on fossil fuels.
In order to support these efforts, the project Small Developing Island Renewable Energy
Knowledge and Technology Transfer Network (DIREKT) is being undertaken. DIREKT is a
cooperation scheme involving universities from Germany, Fiji, Mauritius and Trinidad &
Tobago with the aim of strengthening their science and technology capacity in the field of
renewable energy, by means of technology transfer, information exchange and networking.
Developing countries are especially vulnerable to problems associated with climate change
and much can be gained by raising their capacity in the field of renewable energy, which is a
key area.
This paper introduces the project DIREKT, its aims and the partnership. It will also show how
sustainable cooperation between the science and technology communities of ACP and EU
institutions in the key area of Renewable Energy may be achieved, which is of great relevance
for the socio-economic development of small island developing states. One of features of the
project, namely the establishment of Research and Technology Transfer Centres within each
of the partner countries, will be presented.
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The impact of energy market and actors on the competitiveness of
renewables technologies diffusion in developing countries
Djiby-Racine, Thiam
PhD-Candidate, under the supervision of Sylvie Ferrari (Assistant Professor) and Stéphane Bécuwe
(Director of Research at CNRS), Research Unit in Theoretical and Applied Economics, Department of
Economics, University of Bordeaux (France)
Email: djiby.thiam@u-bordeaux4.fr; Tel: +33556842971
Overview
The issues of global warming and greenhouse gases (GHG) emissions reductions have led many industrialized
countries to set up some mechanisms incentives for the increasing of clean energy production into their energy
portfolios. This frame has led to the industrial development of these clean technologies (wind, solar, biomass,
hydroelectricity, etc) enabling both mitigations and the adaptations of climate change. However, even if these
technologies exist, they are not yet universally well endowed. In fact many innovations of renewable
technologies are carried out in industrialized countries even if the roots of climate change involve both
developing and developed countries.
In this context the best way to enable the diffusion of renewables technologies is to stimulate theirs transfers
between the innovators and the receptors countries. We developed industrial alliances strategies between firms
to investigate how the cooperation between firms located independently both in developed and developing
countries could enable the transfer of renewables technologies. We considered three forms of technology
transfer. A final technology purchase end-use, the technology cooperation and the joint environmental project
implementation.
The purpose of this paper is to analyse under what conditions these two firms will cooperate for the renewables
technologies transfer and what will be the determinants of the cooperation? How the structure of the relevant
energy market impacted on the transfer decision?
Methodology
The methodology mobilized a simple sequential game theoretical model in which two countries (firms) are
considered an innovator firm (in developed country) and a receptor firm (in developing country). We set up the
profits functions which characterize the strategies of each player (country or firm) involved
Results
The results of this paper analysed under what conditions the firm in developed country will choose to cooperate
with the developing country’s firm in term of clean technology transfer? The author found that the cooperation
in clean technology transfer is stimulate by the increasing receptor firm investment in research and development
which captures its technological competence. If the firms decided both to cooperate the developed country’s firm
will always preferred the technology cooperation rather than joint environmental project implementation if its
profit in its national market is higher than the profit of the developing country’s firm in its own market as well.
The sustainability of joint implementation is simultaneously guided by the variation of the international carbonne
price and the variation of the clean energy price in developed country and its policy in favour of demand-side
control. Moreover any increasing of energy price incentives (i.e.: feed-in-tariff) led to the fail of a technology
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transfer rather than the decreasing of energy consumption (demand-side controle, energy efficiency policies)
which generates a stimulus of the technology transfer.
Renewable Energy (RE) Market in Rural Electrification: Country Case Nepal
Brijesh Mainali brijesh.mainali@energy.kth.se
Semida Silveira semida.silveira@energy.kth.se
Energy & Climate Studies, Royal Institute of Technology, Brinellvägen 68, Stockholm 10044 Sweden
Abstract:
Renewable Energy (RE) technologies market is emerging as main stream solution to electrify
poor rural communities. Doing business in rural areas means targeting business in the bottom
section of the economic pyramid. In this sense, promoting these technologies where there is a
low level of economic activity, and low level of technological knowhow, is in fact a
challenging task. On the other hand, this is a large virgin market. For successful operation in
such markets, one must be highly efficient and be able to operate with thin profit margins.
Previous market research has shown that RE-technologies´ market in rural areas is million
dollars market. Efforts of the government, nongovernmental organization, donors and private
sector are equally important in creating RE market environment.
This paper is aiming at analyzing evolvement of RE based rural electrification market in
Nepal and to determine business opportunities and risks correlated with the market. The
paper discussed and analyzed rural electrification supply models, market drivers, market
penetration and distribution in the rural area, employment generation. The analyses are based
on a case study that was carried out in Nepal in 2008 and on the basis of scientific literature
review on RE market. The study also includes a questionnaire survey with key stakeholders
of the sector viz.: private sector installation and manufacturing supply companies of various
RE technologies and local non-governmental organization to get perception of the
stakeholders on RE based rural electrification. The rank graph method proposed by Baba
Yasumasa was used to analyze the preferential rank on the perceptions of the respondent.
Also, data on off grid electrification installation (kW and household electrified and total
household data in each village development committee) of various districts for last 40 years
had been collected from official sources. The off grid electrification rate in electrified
communities (P e / P vdce ) 1 and share of the population of electrified communitiesin the total
rural population (P vdce / P vdc ) was calculated and analyzed in 5 sample districts (with
different HDI ranks and one from each regional development zone). The product of these two
ratios gives the overall off-grid electrification rate (P e / P vdc ). The comparative analysis of
the relation between commodities like ‘electricity’, ‘safe drinking water’ with the ‘income’
was done using electrification index, safe water access index and income index of all 75
districts of the country. The analysis showed that there was a significant increment in the
share of electrified communities in 2006 as compared to 1991. The extensive growth of rural
electrification has been significantly increased in the recent decades and Solar PV has been
instrumental for the same. However, the percentage of electrified units within the electrified
VDCs is fairly low, or less than 50%, showing the uneven distribution and penetration of the
technologies in poor villages. The analysis of stakeholder survey revealed that the access to
easy credit facility is one of the most important elements (with average rank of 1.63 and item
vector magnitude of 0.5 out of 1 which indicated the level of divergence) affecting the
expansion of the RE-market in Nepal followed by cumbersome delivery mechanism of
government subsidy policy (with average rank of 2.24 and item vector magnitude of 0.33)
1 P e is the household population with electricity access, P vdce is the population of the communities (VDC) with
electricityand P vdc is the population of the total VDC.
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among the twelve different elements given for ranking. The results support the fact that
access to credit is still a major factor affecting the RE expansion. Innovations are deemed
necessary to overcome the conventional hurdles.
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IMPLICATIONS OF THE DIFUSSION OF BIOMASS BASED ENERGY
TECHNOLOGIES:
THE CASE OF PELLETS FROM AGRICULTURAL SUBPRODUCTS IN BRAZIL
BRUNA MISSAGIA1, CINTHYA GUERRERO2, HANS JOACHIM KRAUTZ3,
WOLFGANG SCHLUCHTER4
1 Brandenburg Technical University of Cottbus, Chair of Power Plant Technology, Walther-
Pauer Str. 5, 03046 Cottbus, Germany missagia@tu-cottbus.de
2 Brandenburg Technical University of Cottbus, Chair of Power Plant Technology, Walther-
Pauer Str. 5, 03046 Cottbus, Germany guerrcin@tu-cottbus.de
3 Brandenburg Technical University of Cottbus, Chair of Power Plant Technology, Walther-
Pauer Str. 5, 03046 Cottbus, Germany krautz@tu-cottbus.de
4 Brandenburg Technical University of Cottbus, Chair of Environmental Issues in Social
Sciences, Erich Weinert Str. 1, Postfach 10 13 44, 03046 Cottbus
wolf.schluchter@tucottbus.de
In the light of availability concerns and environmental implications of fossil fuels; bioenergy
systems could appear as a promising alternative to promote regional development while providing
numerous benefits across environmental, social, and economic spheres. Brazil, with its vast
agricultural sector, posses a wide range of viable biomass inputs -such as agriculture and forest
residues- that could be used to produce energy. Densification of biomass (e.g. sugarcane bagasse,
saw wood, rice and coffee husks) through pelleting, promises increased storage and transport
efficiencies. The BTU Cottbus has successfully pelletized Brazilian biomass and assessed its
suitability for combustion based on the amount of ashes and chemical composition. The
present work explores the risks and opportunities, key drivers and barriers that might determine
the market penetration of pellets from agricultural subproducts. A holistic model, adapted to the
Brazilian context, was developed in order to illustrate possible cause and effect relationships in
the system of actors and structures which have a stake in the use of these agricultural resources
and conversion technologies. It was concluded that the Brazilian policies for renewable energy
and the management of agricultural and manufacturing practices play a crucial role. The challenge
would now be determining how small farmers and workers from rural areas could benefit from the
upgrading of residues.
Key words: pellets from agricultural and forest sub-products, socio-economic assessment,
renewable energy policies
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An Assessment of Exploiting Renewable Energy Sources with
Concerns of Policy and Technology
Yung-Chi Shen (syc.mt96g@nctu.edu.tw),
Grace T.R. Lin (gtrl@faculty.nctu.edu.tw),
Kuang-Pin Li (kbli.mt96g@nctu.edu.tw),
Benjamin J.C. Yuan (benjamin@faculty.nctu.edu.tw),
Chiyang James Chou (c.james.chou@gmail.com)
National Chiao Tung University
In recent years, the Taiwanese government has vigorously promoted the development of
renewable energy to engage the challenges of gradual depletion of fossil fuels and oil, as well
as the intensification of the greenhouse effect. Since the Sustainable Energy Policy Principles
were announced in 2008, Taiwanese government has declared that the development of
renewable energy should take into account goals that pertain to energy, the environment, and
the economy (3E goals). By using the fuzzy analytic hierarchy process (FAHP), this study
aims to assess the 3E goals and renewable energy sources regulated by the Renewable Energy
Development Bill that passed in 2009. That is, this research attempts to reveal the suitable
renewable energy sources for the purposes of meeting the 3E policy goals. The results first
show that environmental goal is the most important to the development of various renewable
energy technologies in Taiwan, followed by the economic and energy goals. Additionally,
hydropower, solar energy, and wind energy would be the renewable energy sources utilized in
meeting the 3E policy goals.
Keywords: renewable energy, renewable energy policy, fuzzy analytic hierarchy process
Renewable Energy Research Conference 2010 209

The Centre for Renewable Energy
NTNU - SINTEF - IFE
Production of renewable energy from wind power in local communities
Bente Johnsen Rygg
PhD student
Høgskulen i Sogn og Fjordane / Sogn og Fjordane University College
bente.johnsen.rygg@hisf.no
International and national authorities put a lot of emphasis on increasing production of
renewable energy, including wind power. Lately, several goals with focus on renewable
energy from wind power have been set by national authorities. In order to achieve these goals,
local communities play an important role.
This paper investigates the following research questions:
- How do local communities perceive options and challenges with respect to wind
power?
- What strategies do they pursue to implement wind power?
- Who are the central actors related to renewable energy in local communities, and what
are their respective roles?
- What local effects (positive or negative) will efforts to increase production and use of
renewable energy from wind power have on the local communities?
The analysis is based on interviews and analysis of relevant White Papers and other relevant
documents. Central actors have been interviewed in three Norwegian local communities. This
includes political and administrative leaders, representatives of companies that produce wind
power, environmental organisations, inhabitants and farmers that will be affected by
prospective wind power parks. In order to find relevant actors, Latour (2005) and actornetwork
theory has been used. NIMBY (Wolsink 2005, 2000) has been used to understand the
process of establishing wind power parks in local communities, and possible conflicts related
to this.
I find that there are many actors involved in production of wind power in local communities.
Hence, the situation is complex and characterised by a lack of economical, technical and
human resources available locally. The local effects of wind power in Norwegian local
communities are perceived and described in different ways by different actors.
Renewable Energy Research Conference 2010 210

The Centre for Renewable Energy
NTNU - SINTEF - IFE
A Norwegian case study of the formation of a research program for
utilizing natural gas feedstock from the North Sea
Sjur Kasa
CICERO, Centre for International Climate and Environmental Research, University of Oslo
PB.1129 Blindern, N-0318 Oslo, Norway
Email: sjur.kasa@cicero.uio.no
Telephone: +47 22858757
Anders Underthun
Department of Geography, The Norwegian University of Science and Technology
NTNU Dragvoll, N-7491 Trondheim, Norway
Email: anders.underthun@samfunn.ntnu.no
Telephone: +47 90849597
Abstract: This paper explores how political struggles influence innovation policy through a
Norwegian case study on the formation of a state-funded research and development program
for utilizing natural gas feedstock from the North Sea. Despite the apparent dominance of
business, specialized branches of the state, and R&D institutions in the realm of innovation
policy, the key argument of this paper is that labor unions and regional interests exert
considerable influence in shaping national innovation policy, in particular when reflexively
exploiting new forms of state accumulation strategies while retaining a defensive stance
against deindustrialization. First, we argue that the struggle for state funding to natural
gasbased R&D was particularly effective because appropriate strategic political networks and
alliances were mobilized. Second, the construction of strategic arguments to accommodate the
social corporatist heritage of state intervention on the one hand and the competitionoriented
language of flexible specialization on the other, proved crucial for acceptance as a state
strategy. The paper engages a Strategic– Relational Approach to state theory and argues that
this is a useful starting point when studying how particular contexts affect how and why
certain innovation policies emerge. In doing so, we also address the lack of political analysis
in innovation studies.
Renewable Energy Research Conference 2010 211

The Centre for Renewable Energy
NTNU - SINTEF - IFE
Big is beautiful? The gasification of new renewables
Margrethe Aune og Eirik Swensen
Department of interdisciplinary studies of culture, Centre for technology and society
Norwegian University of Science and Technology (NTNU)
tel.:(+47)73591898
email: margrethe.aune@ntnu.no
The government envisions Norway to be an environmentally friendly energy nation
and a leading nation in developing environmentally friendly energy production and
use. Emphasizing (..) renewable energy sources (renewable energy) are central
elements of this politics (White paper no 11 – 2009-2007 p. 1).
The concern for our energy future is driven by worries about future energy supply
combined with the perceived need to curb the emission of CO2. How does energy policy
address these challenges? This paper investigates the development of Norwegian
energy policy in the period 2000 to 2007. Through an analysis of white papers and
official reports (NOU) on energy production and supply the paper will examine how
selected groups of stakeholders (experts and politicians) frame challenges of energy
demand and supply and suggest political and technological solutions. The article
demonstrates that the majority of these white papers and reports engage in the future of
Norwegian gas sector and the development of CCS (carbon capture and storage). The
framing of gas with CCS constructs this system as clean and environmentally friendly
and as a savior – solving the problems of the rising CO2 emissions in countries in
transition. Furthermore the documents emphasize the importance of utilizing
Norwegian expertise from the oil- and gas sector as well as argue how gas is inevitable
in securing future production and supply in Norway. Costs, public acceptance and
present technological challenges are externalized in the calculations of these documents
(Callon 1998). New renewable technologies are on the other hand, framed differently.
Most striking is the requirement for and focus on costs and profitability regarding this
sector. Size is also a concern. Many of the renewable solutions are small scale solutions
and hence very different from the big scale systems represented by hydro power and
oil/gas. The paper concludes that Norwegian energy policy is performed along two nonconnected,
but still competing pathways. In this competition the development of new
renewable technologies in Norway faces a risky future. The political effort of
constructing gas with CCS as clean, environmentally friendly, and technologically
possible has made this system a strong competitor to renewable technologies.
Renewable Energy Research Conference 2010 212

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NTNU - SINTEF - IFE
Supply networks for bioenergy: state support and local actors
Paper to Renewable Energy Research Conference, Trondheim, June 7-8, 2010
Magnar Forbord*, Bengt Gunnar Hillring b , and Jostein Vik a
a Centre for Rural Research, University Centre Dragvoll, N-7491 Trondheim, Norway. Tel.: +47 73591729; fax:
+47 73591275; e-mail: magnar.forbord@bygdeforskning.no; jostein.vik@bygdeforskning.no
b Hedmark University College, Campus Evenstad, N-2418 Elverum, Norway.
Tel. +47 62430880; fax. +47 62430851; e-mail: bengt.hillring@hihm.no
Abstract
In a recent publication (Climate Cure 2020) a number of measures and instruments for
reduced emissions of greenhouse gases in Norway are presented. Around one third of the less
costly measures (below 1200-1600 NOK per ton CO2 reduced) involve bioenergy, like bio
fuels in transportation, conversion from fossil energy to bioenergy in different industries, and
heating with bioenergy in buildings. The level of bioenergy use in Norway is on European
average (around 6 % of all energy used). There exist economic support schemes for
investments, but the state has not so far pointed out bioenergy as a strategic priority. Probably,
new state policies will come in the future making bioenergy more competitive and important.
In a project Centre for Rural Research and Hedmark University College has investigated a
number of bioenergy cases. Some concern farmers cooperating in supplying chip based
heating to schools, others use of wooden waste in the forest industry, and bioenergy in district
heating. Findings are among other things that one can hardly speak about a “pure” supply
chain for bioenergy. Rather it is more constructive to talk about a supply network where
resources are used for many purposes (“economy of scope”). Second, many of the activities
necessary to supply bioenergy are already in place (like felling and timber transportation), so
the development task is as much to integrate new, specific bioenergy activities (like chipping
and operation of boiler) in already existing activity structures, as it is to establish new
activities per se. The cases also show the importance of long term (strategic) thinking and
political will in local municipalities to introduce renewable energy like bioenergy, despite
alternative sources (like electricity) being slightly cheaper. Enthusiastic and patient local
actors also play a significant role. The economy in supplying bioenergy is however modest,
and without public support schemes this production would not have been profitable.
Keywords: Bioenergy; heating; supply networks; forestry; local actors; state support
* Corresponding author
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NTNU - SINTEF - IFE
The governance of hydro power in Norway and Sweden: How to manage the
European current?
Authors: Audun Ruud, Gerd Jacobsen & Jørgen Knudsen, SINTEF Energy Research, Måns Nilsson &
Peter Rudberg, Stockholm Environment Institute
Objectives of the paper:
The proposed paper will be based on studies of renewable electricity production within two different
national contexts. Experiences clearly demonstrate that variations in political settings provide energy
companies with disparate opportunities, constraints and motivations (Lafferty& Ruud, 2008). This is
also the case with two countries as similar as Norway and Sweden. Both countries are, however,
committed by EU-based legislation, not least former and current Directives on renewable electricity
and energy as well as the Water Framework Management Directive. By comparing current
governance of hydropower and how environmental concerns are taken into account, the paper aims
at discussing differences in regulatory practice, and thereby assess to what extent EU legislation
modify and/or reinforce the existing regulatory framework in Norway and Sweden.
Organisation and methodology:
The paper is related to the ongoing research project Governance for Renewable Electricity Production
(GOVREP), which is part of the Centre for Environmental Design of Renewable Energy (CEDREN) one
of the eight newly established Centres for Environment-friendly Energy research. GOVREP aims at
contributing to a better integration of environmental- and energy policy concerns in renewable
electricity production. The authors of the proposed paper are working within the project.
The proposed paper will present a comparative case study of specific hydro power projects. The
research method is based on document analysis as well as interviews with relevant stakeholders. The
primary data to be presented in the paper will thus represent original findings. The research will
employ analytical approaches related to policy analysis and europeanization of national policies.*
Outline of results:
The paper will assess the importance of national differences in regulatory practice vis-à-vis specific
hydropower projects. Furthermore, the paper will provide an assessment as to what extent relevant
EU directives impact upon this practice, and whether EU legislation represents common
requirements that may standardise the regulatory framework in Norway and Sweden.
Lafferty W.M. & Ruud A. (eds), 2008, Promoting Sustainable Electricity in Europe: Challenging the Path
Dependency of Dominant Energy Systems, Cheltenham UK: Edward Elgar.
* See for example Nilsson, M., 2009, “New Dawn for Electricity? EU Policy and the Changing Decision Space for
Electricity Production in Sweden”, CANES Working Paper, FNI Report 11/2009, Lysaker: Fridtjof Nansen
Institute; and Knill C. & Lenschow A., 2005, “Compliance, Communication and Competition: Patterns of EU
Environmental Policy Making and Their Impact on Policy Convergence”, in European Environment, Volume 15,
pp. 114 – 128.
* Contact person: audun.ruud@sintef.no
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NTNU - SINTEF - IFE
Offshore wind power. Market opportunities for the Norwegian supply
industry, and regulatory framework needed to realize these opportunities
(G. Volden, H. Bull-Berg, F. Skjeret, H. Finne and M. Hofmann)
Abstract
Offshore wind power has received much attention these last few years, from governments, NGOs as
well as energy companies. There are still huge technological challenges to overcome, especially
concerning floating constructions on deep water, but offshore wind has a potential to become an
important energy source in the future.
The main objective of our study was to build more knowledge about market opportunities for the
Norwegian supply industry, most of which is closely related to offshore oil and gas activities. We
started by mapping and quantifying the parts of the supply industry that could be relevant to
offshore wind, which is actually most of it. Then, through interviews and questionnaires, we asked
potensial suppliers about their attitude and strategies towards offshore wind. An overwealming
majority was optimistic about future markets internationally, whereas there was less belief in largescale
power production on the Norwegian shelf. Suppliers do not necessarily find the lack of a
Norwegian “home market” to be a barrier. However many of them expressed that the risk is high and
it may be crucial to establish a national demo program, for supplier to test new technological
solutions at low cost, gain references and develop industrial relations with other suppliers.
We argue that being part of an industrial cluster may be a success criterion within offshore wind. By
using Michael Porter’s ”Diamond Model” we analyse Norway’s inherent competitiveness as a
potential host for an offshore wind cluster – with or without energy producers. Norway’s most
important advantage is the existing industrial environment, with a strong maritime sector and
engineering companies with special competence in floating and fixed installations for the oil industry.
Norway also has disadvantages; such as lack of traditions within wind power and wind turbine
manufacturing, as well as high salaries and lack of engineers. So far it is also uncertain whether
Norway has large companies willing to take a “leader role” and developing the smaller and less
experienced suppliers. Public measures will be needed to support the development of an offshore
wind cluster, and based on economic theory we discuss which measures will be most efficient.
In the study we also develop two distinct scenarios for a Norwegian offshore wind cluster towards
2020. The scenarios mainly differ in whether a Norwegian demo program came in place in an early
phase or not. However, also in the non-demo-scenario, a handful of suppliers manage to succeed
internationally.
Renewable Energy Research Conference 2010 215

The Centre for Renewable Energy
NTNU - SINTEF - IFE
E4: Energy markets and energy actors
Agent-based Modelling of Heating System Adoption in Norway
Bertha Maya Sopha a (bertha.sopha@ntnu.no),
Christian A. Klöckner b (christian.klockner@svt.ntnu.no),
Edgar G. Hertwich a (edgar.hertwich@ntnu.no)
a Industrial Ecology Programme and Department of Energy and Process Engineering,
Norwegian University of Science and Technology, Norway
b Department of Psychology, Section for Risk Psychology, Environment and Safety
(RIPENSA), Norwegian University of Science and Technology, Norway
This paper introduces agent-based modelling as a methodological approach to understand the
effect of decision making mechanism on the adoption of heating systems in Norway. The
model is used as an experimental/learning tool to design possible interventions, not for
prediction. The intended users of the model are therefore policy designers. Primary heating
system adoptions of electric heating, heat pump and wood pellet heating were selected.
Random topology was chosen to represent social network among households. Agents were
households with certain location, number of peers, current adopted heating system, employed
decision strategy, and degree of social influence in decision making. The overall framework
of decision-making integrated theories from different disciplines; customer behavior theory,
behavioral economics, theory of planned behavior, and diffusion of innovation, in order to
capture possible decision making processes in households. A mail survey of 270 Norwegian
households conducted in 2008 was designed specifically for acquiring data for the simulation.
The model represents real geographic area of households and simulates the overall fraction of
adopted heating system under study. The model was calibrated with historical data from
Statistics Norway (SSB). Interventions with respects to total cost, norms, indoor air quality,
reliability, supply security, required work, could be explored using the model. For instance,
the model demonstrates that a considerable total cost (investment and operating cost) increase
of electric heating and heat pump, rather than a reduction of wood pellet heating’s total cost,
are required to initiate and speed up wood pellet adoption.
Renewable Energy Research Conference 2010 216

The Centre for Renewable Energy
NTNU - SINTEF - IFE
THE EFFECTS OF ENVIRONMENTAL AND RENEWABLE ENERGY POLICIES ON THE
EXISTENCE CONDITIONS FOR DISTRIBUTED GENERATORS IN ELECTRICITY
MARKETS.
Zaida CONTRERAS
Centre for Energy and Environmental Markets
School of Economics, The University of New South Wales.
Sydney NSW 2052 – AUSTRALIA
z.contreras@unsw.edu.au
Abstract
The aim of this work is to identify the impact of carbon and local pollution control measures, at the same time
with a subsidy to renewable electricity generation on electricity prices and on the market share of locally
generated electricity. The research is undertaken as a theoretical analysis framed in the price leadership model to
investigate the equilibrium conditions for DG to be embedded in the electricity network. This part involves
defining the cost minimising supply curve of a fringe of DG firms and solving the profit-maximisation problem
of the dominant centralised generator, while accounting for the output of small DGs.
Methodology
This paper presents a theoretical microeconomic model using Forchheimer’s price leadership model and
accounting for economic and social costs from local generation and their interaction in the grid network. The
grid network is modelled such that centralised generators act as a dominant main price-setting firm and DGproviders
represent a relatively smaller competitive fringe. In this context, local generation comprises any power
generation technology managed by independent energy service providers that can be embedded in existing
distribution networks. In order to account for heterogeneity in local distributed generation technologies, in a
second stage, various forms of DG such as photovoltaic, biomass, wind and natural gas small power plants, are
characterised in terms of their use of capital, labour and fuel, and their degree of substitutability among inputs.
These technologies are then simulated using different numerical values in the parameters of the theoretical model
as well as assuming other exogenous variables such as taxes. We calculate their short-run output, marginal cost
and environmental impact of the various DG technologies without and in the presence of taxes.
Preliminary Results
We show that the condition allowing simultaneous supply of electricity from distributed generators and the grid
provider is satisfied in markets showing following characteristics: large market size, high willingness to pay and
high marginal costs of the grid network. Further, given a market with these characteristics and in the presence of
distributed generation, the grid provider will maximise its profits by setting the electricity price that
simultaneously will create profits for the industry of the smaller firms. The introduction of separate carbon
emissions and pollution taxes will affect distributed generation in the following ways, (1) given that only taxes
on carbon emissions or pollution are in place, taxes will increase the electricity price and the share of distributed
generation along with their mark up in the interior solution. In the boundary case, it is possible to calculate the
level of emission/pollution taxes that allow distributed generation to start producing in the market. (2) If there is
only a subsidy to small-scale renewable generation, the electricity prices and share of distributed generation
remain unchanged for the interior solution. In the boundary case, a minimum price is required for the small
generators to be active in the market. (3) If all emission, pollution taxes and subsidies for electricity from
renewable energy are introduced, there will be an increase in electricity prices depending on the emission
intensity factors of dominant firms, which at the same time allows distributed generation to increase their share
in the market and profit. As a result of the simulation exercise, we find that marginal costs of photovoltaic
systems are very high in comparison to those from wind energy, and conventional biomass and natural gas
fuelled engines. Therefore, additional environmental taxes will not affect the relative position of photovoltaics
compared to the other DG technologies. In contrast, natural gas engines exhibit the lowest marginal cost without
taxes. However, with environmental taxes biomass and wind energy become the most affordable options. In
particular, biomass is more labour intensive resulting in its final private and social costs to be slightly above than
of wind energy. Following the theoretical model, DG systems with the lowest marginal costs will participate
more easily in the market. In this regard, wind energy together with biomass and followed by natural gas would
be the options to be deployed first in the market, given the existence of policy instruments such as taxes on
emissions and pollution.
Renewable Energy Research Conference 2010 217

The Centre for Renewable Energy
NTNU - SINTEF - IFE
Renewable Energies and their Effect on Electricity Prices: the Case of the German
Nuclear Phase-Out
Work in progress
JEL Classification: Q4, L94, D4
Daniel Comtesse (Universiteit van Amsterdam)
Sebastian Schröer* (Hamburg Institute of international Economics - HWWI)
The aim of this article is to analyse the price effects of the market integration of renewable
energies. Previous related studies describe a so-called “merit order-effect”, implying that
decreasing electricity prices are caused by an increasing share of renewable energies.
However, this is a static effect resulting from the assumption that the existing power plant
fleet remains constant. Our contribution is to analyse the long-run price effect of the
substitution of renewable energies for existing technologies like nuclear power, coal or gas.
This aspect is relevant, since more and more countries increase the share of renewable
energies in order to substitute fossil or nuclear power plants. Higher market shares of
renewable energies are caused both by their increasing competitiveness and by political
actions such as national targets or promotion schemes.
Background and Stylized facts
Since renewable energyes usually have a lower marginal price of electricity generation –
which determines the electricity prices at spot markets – their addition to an established power
plant fleet consisting of nuclear, coal, lignite and gas power plants leads to lower electricity
prices. However, the long-run price effect when fossil or nuclear power plants are substituted
remains ambiguous. This is due to the fact that, if compared to fossil and nuclear fuels,
renewable energies are characterized by three specific features: firstly, they lack the ability to
secure base load. Secondly, they produce energy which is extremely volatile. Thirdly, their
marginal costs of production are close to zero. These characteristics are caused by the high
dependency of renewable energies on weather conditions. As electricity generation and
consumption must happen simultaneously (electricity storage does not pay off yet), power
plants with low base load capacity need back-up capacities. Given the actual technological
state of the art, these back-up capacities must be fossil or nuclear power plants. The price
effect therefore highly depends on the cost structure of the back-up power plants. In our
article we use the example of the nuclear-phase out in Germany. This analysis is particularly
in the current economic and political context relevant: while on the one hand in Germany, a
country committed so far to a nuclear phase-out until 2020, the new government seems to
reconsider this initial plan, on the other hand, worldwide we experience a fall in the share of
nuclear power plants – with more nuclear power plants being closed than new ones build.
Data and methodology
Our analysis of price effects is based on spot market outcomes. Though only a minority of the
market volume is traded at the spot markets, spot market prices have a strong impact on future
transactions and bilateral contracts. In line with this idea, spot market prices are a good
measurement for price effects. We use a basic spot market model, where the merit-order
supply function aggregates different energy sources according to their marginal cost. This
leads to an upward sloping supply function. We model the supply side by a stylized power
plant fleet using International Energy Agency (IEA) data on marginal costs. Since in reality
consumers can not change their usage grid and do not change their behaviour in the short run,
the demand function is for simplicity assumed to be perfectly inelastic. We use data of the
European Energy Exchange (EEX) on an hourly basis to model electricity demand. Based on
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NTNU - SINTEF - IFE
comparative statics, we develop different scenarios and check for different base load
capacities of renewable energies. The basic assumption of all scenarios is the substitutability
of nuclear power plants by renewable energy sources. In order to show the effects of a nuclear
phaseout against fluctuations of base load capacity of renewable energies, several back-up
scenarios for base load capacity with other energy sources are developed. These scenarios
contain extreme case settings in order to show the price effect one energy source has. The
scenarios under consideration concentrate particularly on coal and gas as back-up energy
sources. This is due to the fact that other energy sources such as lignite are not traded at spot
markets. Moreover, energy sources like diesel or oil are very expensive and are therefore
rarely used for permanent electricity generation. The analysis is arranged numerically by
Monte Carlo simulations. These are very useful for our analysis because they facilitate the
computability of high-dimensional problems such as the price building in energy markets.
Furthermore the state space does not need to be discretized which is crucial for fluctuating
demand and supply of electricity.
The spot-market is at first simulated one million times for each scenario. Since the price effect
mainly depends on the long-run base load capacity of renewable energy sources, for each
scenario 100 000 price effects in the spot marked are simulated for 200 different values of
base load capacity of renewable energy sources. To simplify the analysis, within one day the
hour of investigation is evenly distributed as a discrete random variable between 0 and 23.
According to the law of large numbers the expected value of 23 single analyses should be the
same as the expected value of the results of the hour of investigation of an evenly distributed
discrete analysis random variable.
Results
Our results show a high price effect of the low base load capacity of renewable energies.
There is a significant price increase in every scenario. However, if coal is the only back-up
technology without any costs of CCS or ETS, the price will decrease no matter how high the
base load capacity of renewable energies is. In line with the impact of the base load capacity,
we find two surprising results: the first one refers to the fact the electricity prices decrease
concave rather than linear with increasing base load capacity. The second one shows that the
slope of the curve is constantly increasing, meaning that up to 50 % of the base load capacity
there is almost no price effect. This demonstrates the high importance attached to base load
capacity and the subsequent need to invest into technological solutions.
*Corresponding author: schroeer@hwwi.org Tel: 040 34 05 76 – 357
Renewable Energy Research Conference 2010 219

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NTNU - SINTEF - IFE
Title: An Optimization Model for Biogas Production at District of
Columbia Water and Sewer Authority
Authors: Dr. Steven A. Gabriel, Associate Professor, Dept. of Civil & Env.
Engineering, University of Maryland, College Park, Maryland, 20742 USA
(presenter)
Ms. Chalida u-Tapao, Ph.D. student, Dept. of Civil & Env. Engineering,
University of Maryland, College Park, Maryland, 20742 USA
E-mail: sgabriel@umd.edu
Abstract: In this talk we present a recent optimization model for the District of Columbia
Water and Sewer Authority (DCWASA) located outside Washington, DC. This model takes
into account that influent can be processed into biosolids for land application, converted into
biogas via digesters and then used internally for electricity production, selling electricity or
gas to the grid. We present the model and some illustrative results taking into account
different and competing objectives.
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NTNU - SINTEF - IFE
Green certificates as climate policy instrument
by Frode Skjeret (Frode.Skjeret@snf.no)
Institute for Research in Economics and Business Administration, Bergen.
This paper discusses the relevance of green certificates as a policy tool for meeting targets of
emission-reductions of climate gases causing global warming. While a large fraction of research on
policy tools discusses incentives to invest in renewable production technologies, the current paper
discuss incentives to shut down production plants emitting climate gases. I first define relevant fixed
costs of (i) operating and (ii) owning production plants, and in particular how these costs’ affect
decisions to reduce or bring production to a standstill (fixed costs), and decisions about shutting
down a plant completely (sunk costs). I incorporate these types of costs into an economic model of
production and investments (and disinvestments).
Then I discuss to what extent green certificates give incentives to shut down existing production
capacities in purely thermally fuelled markets, focusing on gas-fired power plants and coal-fired
power plants varying with respect to share of fixed and sunk costs. The paper illustrates how taxes
are superior to green certificates when it comes to providing incentives to reduce production from
technologies emitting relatively more climate gases.
Finally, and noting that hydropower production technologies are technologies with substantial share
of fixed costs, I discuss the relevance of green certificates in the Norwegian electricity market based
almost exclusively on hydropower production. First I illustrate how a green certificate market causes
sizeable redistribution of surpluses from current production owners (that is the Norwegian state,
counties and municipalities) to new production technologies. Second, I illustrate how green
certificates potentially become worthless if Norway become a large exporter of electricity to
electricity markets outside of the certificate market (Norway or Norway and Sweden). The problem
relates to the substantial share of fixed and sunk costs involved in hydropower production, and the
fact that Norwegian consumption of electricity determines the demand for certificates. I illustrate
that export of electricity to markets outside of the certificate market (e.g Denmark and/or
continental Europe) creates a wedge between production and consumption, causing an excess
supply of green certificates, potentially making green certificates worthless. I also discuss to what
extent it is necessary to subsidise investments in renewable production technologies in Norway
using a dataset from NordPool and the Norwegian Directorate for Water and Energy (NVE).
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NTNU - SINTEF - IFE
Impacts of climate change on the Norwegian Energy System
Audun Fidje a (audun.fidje@ife.no), Pernille Seljom, Eva Rosenberg, Jan Erik
Haugen b , Michaela Meir c
a Institute for Energy Technology (IFE), Kjeller, Norway
b The Norwegian Meteorological Institute
c University of Oslo, Dep. of Physics
Abstract
The aim of this paper is analyse effects of climate change on the Norwegian energy system
towards 2050. Effects of climate change on both energy supply, i.e. hydro and wind power
and end use demand, i.e. heating and cooling demand is analysed.
The starting point of the analysis is regional climate data for a scenario period (around 2050)
and a reference period representing today’s climate. The regional data are developed by The
Norwegian Meteorological Institute using the regional climate model HIRHAM on global
climate change data. The model is applied on 10 different emission sceanrios and global
climate models in order to obtain a range of possible futures. The climate data investigated
here is changes in precipitation and wind for energy supply and changes in temperature and
solar radiation for energy demand (i.e. heating and cooling).
Results from the analysis of climate data is implemented in the energy system model
MARKAL in order to investigate the effects of both changes in supply and demand. The
MARKAL model for Norway covers the energy system from energy supply, through
processes and conversion to electricity and heat to end use demand. Here, the stochastic
version of the linear programming model MARKAL is applied to analyse the effects of the
uncertainties of changes in supply and demand due to climate change. The analysis with
MARKAL is ongoing and will be finalised in March/April. Typical results from the analysis
will be investment needs in new renewables given the uncertainties in climate change.
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NTNU - SINTEF - IFE
Optimal investments in hydrogen infrastructure for the transport sector
Jogeir Myklebust, Department of Industrial economics and Technology Management,
Norwegian University of Sci-ence and Technology (NTNU)
Asgeir Tomasgard, Department of Industrial economics and Technology Management,
Norwegian University of Sci-ence and Technology (NTNU)
Abstract
Hydrogen can be produced from any primary energy source, and if it is consumed in fuel cells
it does not cause any local emissions. We expect that the demand for hydrogen as an energy
carrier in the transport sector will increase because of the political willingness to exploit these
properties to reduce pollution and diversify primary energy sources. The choice between
electrolysis and steam methane reforming (SMR) at different locations and points in time is
used as a test case. SMR can either be centralized, which takes advantage of the process'
economies of scale and allows CO2 capture and sequestration (CCS), or decentralized
exploiting existing energy infrastructure. We study one area, which consist of regions of the
same population distribution and size as the 16 Bundesländer in Germany. We model the
regions as a set of nodes with different populations and distances. Both hydrogen demand
growth and relative input prices are modeled as deterministic. Our three cases differ in their
combination of these prices. The case results illustrate how price combinations affect the
optimal choice of technology.
Renewable Energy Research Conference 2010 223

The Centre for Renewable Energy
NTNU - SINTEF - IFE
Bills to pay – Consumers and policymakers’ reactions to
problems with the liberalised market for electricity
Henrik Karlstrøm, NTNU. henrik.karlstrom@ntnu.no
The Norwegian market for electricity has been completely deregulated since 1991 and allows
consumers to freely choose their supplier of electricity. Conventional economic theory
postulates that consumers will actively exploit price differences and thus drive efficient
competition between electricity utilities. However, research shows that most consumers are
not particularly active users of the possibilities offered by this free competition, even if some
do engage with the options offered by a deregulated market.
In the case of the Norwegian market for electricity, prices may multiply rapidly if a series of
conditions such as transfer capability problems, import restrictions and increased demand due
to low temperatures are met. In the winter of 2002/2003, a combination of all these occurred,
leading to an eightfold increase in electricity prices in the course of days and sparking a
heated debate over the policy for pricing of electricity. The outcome was the construction of a
new, high-emission mobile gas plant, which has yet to be put to use. In the winter of
2009/2010, this situation was repeated, with debate over how to either fix prices at a “more
reasonable” level or how to quickly increase the production of electricity to meet increased
demand. Evidently, this situation is fated to reoccur as long as the current regime is operative.
Using data from a statistically representative telephone survey about consumer preferences, I
analyse responses about opinions on the need for political control over the construction of
new electricity production facilities and control over pricing. The data is combined with a
large sample of newspaper articles about the problems of prices that are at times very high.
Together, this gives us an idea of how policy decisions are constantly up for revision, and
how a supposed “de-politicised” policy field can again be subject to intense political debate.
Renewable Energy Research Conference 2010 224

The Centre for Renewable Energy
NTNU - SINTEF - IFE
Investing in a CO2 value chain with Enhanced Oil Recovery
Adela Pages, Department of Industrial economics and Technology Management, Norwegian
University of Science and Technology (NTNU)
Asgeir Tomasgard, Department of Industrial economics and Technology Management,
Norwegian University of Sci-ence and Technology (NTNU)
Abstract
Among the actions contemplated for carbon abatement there is Carbon Capture and Storage
(CCS). CCS is seen as a bridging solution between the current way of supplying energy (based
mainly on combustion of fossil fuels with large CO2 emissions) and a future based on renewable
energy. CCS consists on separating the CO2 from exhaust fumes of large emitting industries,
compress it and transport it to suitable storage locations. The storage of CO2 can be done in
geological formations (such as aquifers) for a safe and long-term isolation. CO2 can also be
injected into mature oil fields as an Enhanced Oil Recovery (EOR) method. This method gives
extra value to the CO2 since additional barrels of oil are recovered due to the action of the CO2.
The economical incentive for CO2 storage is then to avoid buying CO2 allowances. In
addition if CO2 is used for EOR there is the income from the extra oil recovered. The use of CO2
for EOR has high potential but with large financial risks.
In order to analyze how a CO2-EOR value chain can be realized in Norway we use an
investment model that optimizes the Net Present Value by deciding the network structure, the best
suited storage/injection points and the investment timing. The model developed will be presented
together with a base case. Analysis of the results will be discussed.
Renewable Energy Research Conference 2010 225

The Centre for Renewable Energy
NTNU - SINTEF - IFE
E5: Cultural dynamics of new renewable energy
technologies
Ulrik Jørgensen, prof.
DTU Management
Innovation and Sustainability
Comfort, mobility, growth, efficiency – conceptual frames or blinders for disciplinary
engagements in transition processes?
In the literature on transitions to a low carbon or sustainable society consumer preferences
and fundamental economic mechanisms are very often seen as serious obstacles to sustainable
solutions. These obstacles are supported by specific and rather basic notions derived from the
discipline based approaches taken in research but also in public and political discourse
emphasising certain phenomenon as e.g. consumers striving for improved comfort, citizens
identifying mobility with freedom, societal economies building on a growth paradigm, and
industrial processes focusing on cost reductions and efficiency.
The paper will survey four notions and corresponding theoretical concepts: comfort, mobility,
growth, and efficiency highlighting their specific contexts within scientific discipline and
philosophical envisioning. Their historic contingency will be highlighted as well as how they
have been part of socio-technical visions related to some specific epochs in societal
development. While some scientific disciplines and political discourses take for granted such
historic projections and help reproduce them as difficult to reject or neglect, the paper’s idea
is to open for a demystification and deconstruction of these core concepts by identifying their
specific historic relations and emergence and relations to new socio-technical regimes.
Examples of new technologies are challenged by these established regimes and are forced to
produce visions of a changing society to sustain their appearance and performance hereby
either aligning with or bringing in alternatives to transition processes.
All four concepts have been assigned a rather fundamental role in the formation of a post-war
consumer society based on a well-fare model of society where consumption was created as
the core engine of development and transformation of societal institutions. While such models
and conceptual framings of society and its institutions are not easily transformed and will
survive during a long period of controversy, identifying their historic routing opens for
criticism and the potential of developing alternative visions.
Renewable Energy Research Conference 2010 226

The Centre for Renewable Energy
NTNU - SINTEF - IFE
Changing fields of rationality – a policy for change?
Authors: Strumse, E., H. Westskog and T. Winther.
E-mail addresses: Einar.strumse@hil.no, hege.westskog@cicero.uio.no, tanja.winther@sum.uio.no
Affiliations: Einar Strumse – Høyskolen I Lillehammer, Hege Westskog – CICERO, Senter for
Klimaforskning, Tanja Winther – Senter for Utvikling og Miljø, Universitetet I Oslo
Work objective: To analyze effective strategies for changing households’ energy consumption
based on an interdisciplianry model for understanding change.
Methodology: In this paper we develop a conceptual model for understanding individuals’ energy
consumption. We synthesize insights from anthropology, social psychology and economics grasping
perspectives from behaviour to practice and from the Bourdieu’s fields to rationality thinking in
economics. We use this insight to analyze strategies for change.
Abstract:
In this paper we analyze effective strategies for changing households’ energy consumption based on
an interdisciplinary model for understanding change. The model focuses on four main categories for
understanding individual consumption:
a. Material constraints
b. Values and identity
c. Norms
d. Ability
These are the main influencing factors of the individual’s consumption level, but in interaction with
the corresponding group and the societal levels for the same factors. The model can be illustrated in
the following way:
One combination of factors on all levels constitutes a field of rationality. We claim that an important
strategy for changing energy consumption towards sustainability is changing the field of rationality
of the individual. Changing of rationality fields would from our point of view initiate reflection which
is an important condition for changed behavior. One example of changing of fields is information
measures that relates energy consumption to the “citizen” field rather than the “consumer” field.
Hence, according to our conceptual framework - how policy should be framed (information
measures for instance ) would be an important knowledge area for design of effective policy
measures.
Renewable Energy Research Conference 2010 227

The Centre for Renewable Energy
NTNU - SINTEF - IFE
How to live CO2 neutral in bathrooms, offices, living rooms
and kitchens?
Thomas Berker, KULT-NTNU: thomas.berker@ntnu.no
Helen Jøsok Gansmo, KULT-NTNU: helen.gansmo@ntnu.no
After the establishment of man made climate change as hard scientific fact, the promise that
human activity can be (near) neutral in terms of greenhouse gas emissions has attracted
considerable political attention as well as research funding.
Unfortunately, with respect to the end-user, the resulting research and policy is too often
based on a simplistic definition of CO2 neutrality as ‘the minimisation of the aggregated CO2
emissions attributable to an individual combined with individual behaviour which neutralises
the remaining emissions’. Climate calculators which recently have surfaced on various
websites represent this approach most clearly and similar reasoning is used extensively in
public discussions about climate change. This perspective struggles with severe problems
hidden behind the facade of clear-cut cause-effect relations. This is because the lion’s share of
emissions always occurs ‘far away’ from the individual. Take for example the simple act of
consuming a sandwich: Emissions caused by this act are distributed widely in time and space,
and depend on a plethora of choices made by other people at other places. The technologies
involved in production and distribution of the sandwich are neither chosen nor operated or
even touched by the hungry individual; still it is made responsible for a certain amount of
CO2 emitted by these technologies. In order to establish a plausible link between individual
act and aggregated emissions, thus, the manifold mediating factors are ignored which make
the individual’s actions possible. Only when based on this simplification, appealing to the
individual using moralising arguments appears as promising measure in the struggle against
climate change – measures which have shown their severe limitations over and over again.
In this paper we wish to discuss findings of research which is based on less trivial definitions
of human activity. We are well prepared for this task by studies showing that and how human
action is embedded in both everyday practices and socio-technical networks.
Here we propose to focus on mainly four areas of human activity: relaxing/entertaining (the
living room), eating/preparing food (the kitchen), personal/environmental cleanliness (the
bath), and clerical work (the office)*. These areas each consist of activities more directly
bound to instrumental concerns, for example the production/reproduction cycle, and the
provision of nutrition and basic hygiene. At least as important, however, is that these are some
of the most important arenas where social distinction, meaning production and identity
formation is taking place.
Based on this research and our own studies of the meaning of aesthetics in domestic settings
we aim at both broadening the theoretical horizon and deepening our understanding of
individual practices and socio-technical networks. Additionally, the development of nonreductionist
research on mediations and mediators between micro and macro perspectives on
CO2 emissions is in dire need.
* We are aware that these areas are neither mutually exclusive nor do they cover all greenhouse gas
emitting activities in everyday life. Especially transport deserves a corresponding treatment but is not
covered by the funding agency of this workshop.
Renewable Energy Research Conference 2010 228

The Centre for Renewable Energy
NTNU - SINTEF - IFE
Discourses of community-based renewable energy project in the
case of Korea
Author(s) name(s) and organization(s): Jeong Y. † , Walker G. †
† Lancaster Environment Centre, Lancaster University
E-mail address: y.jeong@lancaster.ac.uk
Recent expansion of renewable energy (RE) development has highlighted how a decentralized
energy supply system can enable local involvement in energy sectors and encourage new
entrants into the energy market. The idea of small-scale projects empowering local people
was introduced through the alternative energy movement in the 1970s, but growing concerns
about CO2 emissions and continued conflicts over large scale RE projects have reignited
arguments about the role of a community-based approach in RE development. Nonetheless,
community-based RE projects are far from homogeneous because of the diversity of the
meaning of "community" and the complexity of the contexts that the projects emerge in. This
paper investigates how and why a community-based RE project emerged in Buan in South
Korea. The diverse discourses mobilized by different stakeholders (social actors) are
examined through employing critical discourse analysis as an analytical and methodological
approachThrough in-depth interviews with stakeholders of the RE project, several key
themes revealed in different discourses are identified and the asymmetric power relations
underlying the contested discourses are discovered. This paper will contribute to enhancing
our understanding of the meaning and diversity of RE projects in particular non-western
countries and thereby provide some useful insight about RE policy.
Renewable Energy Research Conference 2010 229

The Centre for Renewable Energy
NTNU - SINTEF - IFE
Psychological Factors in the Diffusion of Sustainable Technology:
A Study of Norwegian Households’ Adoption of Wood Pellet
Heating ‡
Bertha Maya Sopha a (bertha.sopha@ntnu.no),
Christian A. Klöckner b (christian.klockner@svt.ntnu.no)
a Industrial Ecology Programme and Department of Energy and Process Engineering,
Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
b Department of Psychology, Section for Risk Psychology, Environment and Safety
(RIPENSA), Norwegian University of Science and Technology, NO-7491 Trondheim,
Norway
This paper aims to understand the determinants of the adoption of wood pellet technology for
home heating to identify possible strategies towards the slow diffusion of wood pellet in
Norway. A mail survey of 737 Norwegian households was conducted in 2008, involving
wood pellet adopters and non wood pellet adopters as respondents. An integrated model
combining psychological factors (such as intentions, attitudes, perceived behavioral control,
habits and norms), perceived wood pellet heating characteristics, and ecological and basic
values is applied to predict the installation of a wood pellet stove retrospectively. Results from
a path analysis gain empirical support for the proposed integrated model. Wood pellet heating
adoption is mainly predicted by a deliberate decision process starting with the evaluation of
heating system characteristics, mediated by attitudes and intentions. Perceived behavioural
control and habits pose relevant barriers to the adoption process. The influence of norms and
values are indirect and only minor in the given market conditions. The most important heating
system characteristics in the analysis were perceived functional reliability and perceived
installation and maintenance costs. Possible intervention strategies to speed up wood pellet
adoption in Norway are discussed in the last part of the paper.
‡ Submitted to Energy Journal
Renewable Energy Research Conference 2010 230