Solar Thermal Power Plants - Renewable Energy: Technology, Economics and Environment - page 191

observed plant, the annual overall operation costs thus amount to approximately
1.5 Mio. €.
Electricity generation costs. On the supposition of the above-mentioned invest-
ment as well as operation and maintenance costs, the power generation costs re-
lated to the solar tower power plant at the reference site amount to approximately
0.13 €/kWh (Table 5.4).
Power generation costs are largely influenced by the number of full-load hours
per year, the investment costs and the mean interest rate. A sensitivity analysis
conducted on the basis of these parameters reveals the correlations shown in
Fig. 5.13. If investments are, for instance, reduced by 30 % power generation
costs are cut down to approximately 0.10 €/kWh.

0.20 0.20

Depreciation period Depreciation period Depreciation period

0.18 0.18

25 a = 100 % 25 a = 100 % 25 a = 100 %

0.16 0.16

Total investments Total investments Total investments

99 Mi o. € = 1 00 % 99 Mio. € = 100 % 99 Mio. € = 100 %

0.14 0.14

Operation costs Operation costs Operation costs

0.12 0.12

1.5 Mi o. € = 1 00 % 1.5 Mio. € = 100 % 1.5 Mio. € = 100 %

0.10 0.10

Interest rate Interest rate Interest rate

0.08 0.08 4.5 % = 10 0 % 4.5 % = 100 % 4.5 % = 100 %

0.06 0.06 Full-load hours Full-load hours Full-load hours

70 70 80 80 90 90 100 100 110 110 120 120 130 130 2,100 h/a = 1 00 % 2,100 h/a = 100 % 2,100 h/a = 100 %

Fig. 5.13 Sensitivity analysis related to the power generation costs of the reference solar
tower power plant

Parameter variation in % Parameter variation in %

However, the sensitivity analysis also shows that for other economic parame-
ters (i.e. higher interest rates, short depreciation period) and different conditions
for the particular site, power generation costs can vary significantly.

Environmental analysis. The following analyses are aimed at discussing selected
environmental effects with regard to plant erection, normal operation, malfunc-
tion, and the end of operation.

Manufacture (construction). Environmental effects related to solar thermal plants
may already arise during production of the different plant components. They are
to a large share the same as for conventional power plants and other industrial
production processes. However, the resulting environmental effects are restricted
to very limited periods of time, and in many countries they are subject to exten-
sive legal requirements. Furthermore, solar thermal power plants are primarily
located in deserts and steppes where the population density is relatively low. This
is why there is so far only a very limited knowledge on the potential effect on
human beings and on the environment.