OES Annual Report 2012 - Ocean Energy Systems

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Voith Hydro Wavegen in Inverness, Scotland is a “Center of Competence” in wave power, driving forward
research and development in wave power systems. Voith Hydro Wavegen focuses on the conversion of
wave energy using the principle of the oscillating water column (OWC). In the year 2000, the 250 kW trial
system Limpet was brought into service on Islay at the Scottish west coast, where it has been generating
electricity and feeding it into the network ever since. Limpet is the only wave-powered plant worldwide to
have continually produced power over the past 10 years, feeding it into the network on the Isle of Islay. Up
until the end of 2011, it had been running for more than 75 000 operating hours. System availability stands
at over 98 %, and has been so continuously since 2009.
The world’s first breakwater wave power plant was commissioned in the summer of 2011 on the Spanish
Atlantic coast at Mutriku using Voith Hydro Wavegen technology. It has a nominal output of some 300
kW, and can supply around 250 households. The system consists of 16 Wells turbines, each with a rated
performance of 18.5 kW. It was built into the breakwater around the harbor at Mutriku, which was re-built
by the local municipality. The Mutriku power plant has been operated successfully since its opening by the
Basque energy agency, EVE, and is currently the only commercially-operated wave power station in the
world. (source: Voith Hydro)
In 2011 the chair of structural analysis at the Technical University Munich started a collaboration project with
Ed. Züblin AG on the numerical simulation and optimisation of the foundations of ocean current turbines
with a focus on the fluid structure interaction. The public funded project will be completed in 2013.
The Institute for Fluid and Thermodynamics (IFT) of the mechanical engineering department at the University
of Siegen started a 3 year public funded research project on the development of a bidirectional radial air
turbine for application in OWCs at the end of 2011. Based on analytical, numerical and experimental
methods using a specially designed air turbine test facility a radial turbine design is developed and
optimised. The university collaborates with Voith Hydro on the design optimisation of Wells turbines. The
Limpet site can be used for field tests of the new design.
Since 2012 Andritz Hydro GmbH develops drive train concepts for tidal turbines with around €1 million
funding from the BMU. The focus of the project is the economic and technical optimisation of a variable
pitch mechanism for bidirectional operation and the blade connection to the hub. The design will aim at
full scale rotors with maintenance intervals of 5 years. Under the Andritz Group based in Austria Andritz
Hydro Hammerfest established in 1997 in Norway represents the technology provider in the tidal power
business. Based on a 300 kW tidal turbine, tested in Norwegian waters, a 1 MW tidal device was developed
and tested at EMEC site before becoming part one of the world’s first tidal arrays, planned for installation
in Scottish waters in 2013. (source: Andritz Hydro)
The German marine propulsion specialist Schottel placed an investment into the UK tidal-power technology
developer TidalStream Ltd. in 2011. For Schottel renewable energy is an interesting and forward-looking
addition to the traditional product range portfolio. The Triton platform technology comprised of a semisubmerged
turbine-carrying catamaran structure is expected to enable efficient installation of large power
arrays and provides easy maintenance access. The Triton S concept is tailored to operate totally submerged
for “non-surface piercing” applications by using a rigid swing-arm tether foundation, designed to be towed
to site, mated with turbines and deployed into operating position via water-ballasting. After completing
the ongoing 1:10 scale field test, upscaling of the technology is ongoing with the Triton 3 for intermediate
water depths with the capacity to generate up to 3MW from a single installation followed by the Triton 6
designed for deep water sites to accommodate turbines of up to 10MW capacity.
At the occasion of the International Tidal Energy Summit in November 2012 in London, Schottel presented
its first TIDAL Generator STG 50. The light-weight and robust tidal generator is based on the fact that
reducing turbine size leads to a better ratio of power and material use. High overall power can be reached
with a higher number of turbines. STG 50 is a horizontal free flow turbine with a rotor diameter of 4.0 to
4.5 m and a rated power of 45 to 50 kW. It is designed to be composed in arrays of various types and
ANNUAL
REPORT 2012