Solar Thermal Power Plants - Renewable Energy: Technology, Economics and Environment - page 201

Economic analysis. Within the following analysis the power generation costs for
the outlined solar thermal plants are calculated. In line with the preceding assess-
ment method applied throughout this topic, the costs for construction and opera-
tion are determined and distributed in the form of annuities over the technical
lifetime of the plants. Based on these yearly costs and the provided electrical en-
ergy, the electricity generation costs per kilowatt hour are calculated. To allow for
a comparison, as usual a technical lifetime of 25 years and an interest rate of
4.5 % are assumed.
Since such plants are only installed in areas with a high share of direct radia-
tion, also a reference site has been assumed, which is characterised by an annual
direct radiation total of 2,700 kWh/m 2 .
The key data of the assessed 50 MW parabolic trough power plant are outlined
in Table 5.7. The plant is defined similar to the AndaSol I power plant /5-15/;
differences are due to the selected reference site.

Table 5.7 Key data of the assessed 50 MW parabolic trough power plant equipped with
integrated thermal storage
Nominal capacity 50 MW

Mirror surface a 510,000 m 2

Full-load hours 3 680 h/a

Storage for 7 h Molten salt

Solar share 100 %

Technical lifetime 25 years

a sufficient for a 80 MW power plant without storage.

Investments. Investment costs for such a power plant vary between 220 and
300 Mio. €. Here a mean of approximately 260 Mio. € is assumed. Specific in-
vestment costs therefore amount to 5,200 €/kW, including storage. Table 5.8
shows the approximate distribution of the investment costs.

T able 5.8 Estimation of the investment costs of a parabolic trough solar power plant
Power plant (including thermal balancing) 60 Mio. €

Solar field including heat transfer fluid loop 155 Mio. €

Solar field preparation (i.e. levelling, fencing, access roads) 5 Mio. €

Subtotal (without energy storage) 220 Mio. €

Thermal energy storage (7 h storage) 40 Mio. €

Total 260 Mio. €

Operation costs. Annual operation costs of the collector field are estimated at
5 €/m 2 . In addition, there are costs for the remainder of the power plants. All in
all, the operation costs for plants of such a size are estimated at 10 €/m 2 of mirror
surface and year.

Electricity generation costs. Based on the above-mentioned investment, operation
and maintenance costs as well as the possible electricity generation, for the refer-