SUFFiciENcy EcONOMy ANd GRASSROOtS DEvElOPMENt

The Meaning of Sufficiency Economy
International Conference
257
A case study by Razak et al (2009) showed that reducing the excess electricity
from 55% to 3% again reduces the Levelized Cost of Energy by about 50%. This
implies that renewable energy options to be deployed must be meeting the local
requirements according to their hourly demand load curves. Another alternative is to
limit the load towards the dominant power supplier in the renewable energy hybrid
system. This is to ensure that the initial capital and annualized cost to be at its
minimum. Literature reports that in general, at places with higher wind speeds, it is
more suited that wind to solar ratio be greater than one (around 1.43) (Habib et al
1999). In some cases, it has gone as high as 4.5. Moreover, this ratio, generally
greater than one, is very site specific and varies from site to site. Hence, on a general
scale a ratio of 1.85 was arbitrarily chosen to take round figure values for the ease of
simulation of payback analysis.
The base case assumptions and calculations for simulation of payback analysis
were as follows:-
1. Windy regions include Tamil Nadu, Rajasthan, Andhra Pradesh, Karnataka
and Gujarat according to the Wind Map of India (Figure XX) (DOT 2008).
Hence, the analysis including biomass fuel price and electricity tariff for
wind and biomass takes into account the prevailing prices in these regions
only.
2. Total requirement is calculated in kWh/day of a community, and that is
assumed to be constant. To fulfill these energy requirements, individual
models are developed with varying capacities according to their CUF/PLF
and these are analyzed for their payback.
3. Electricity tariffs for solar are constant at 18.44 Rs/kWh in all states for the
first year of operation.
4. Plant is assumed to have been built by starting of FY 2009-2010. Hence, its
capital cost is considered to be same as normative cost for the FY 2009-
2010. This is taken as Fixed cost component and is reflected in FY 0 in the
simulation of various models to highlight its contribution.
5. The minimum lifetime out of solar, wind and biomass is that of biomass –
20 years (CERC 2010).
6. The tariff period is valid for 13 years. Hence, payback analysis simulation
has been carried out till 13 years.
7. The average CUF or PLF of the plant varies with time to time. In general,
we assume the efficiency increases slightly initially (as stabilization issues
get resolved) and then decrease (as equipments wear out).
8. Biodiesel generator and battery back-up costs and revenues aren’t included
as they are considered to be same for the same capacity requirements. As
their costs and revenues would remain same in all the cases