Solar Thermal Power Plants - Renewable Energy: Technology, Economics and Environment - page 190

Since the installation of solar thermal plants only makes sense in areas with a
high share of direct radiation, a reference site with a total annual global radiation
on the horizontal surface of 2,300 kWh/m 2 and a direct radiation total of
2,700 kWh/m 2 has been defined. Such values can, for instance, be obtained at
favourable sites in California or North and South Africa.
Based on these site conditions a 30 MW solar tower power plant provided with
an open volumetric receiver is assessed. The corresponding technical data are
outlined in Table 5.3. This plant is state-of-the-art in terms of solar tower technol-
ogy.

Table 5.3 Technical data of the assessed 30 MW solar tower power plant
Nominal capacity 30 MW

175,000 m 2 Mirror surface

Full-load hours 2,100 h/a

Storage capacity 0.5 h

Solar share 100 %

Technical lifetime 25 a

Investments. To date, no commercial solar tower power plant has been put into
operation. To estimate the power generation costs, we thus need to revert to the
figures published by manufacturing and project development companies. On the
basis of these data and the adapted specific costs for the heliostats, the overall
investment costs for such a power plant amount to roughly 99 Mio. € (Table 5.4).
Within the scope of a sensitivity analysis the influence of investment cost varia-
tions on the power generation costs are assessed.

Table 5.4 Mean investment and operation costs as well as resulting power generation costs
for the reference solar tower power plant
Nominal capacity 30 MW

Investments

heliostat field 30 Mio. €

receiver and steam generator system 20 Mio. €

tower 15 Mio. €

other components 20 Mio. €

assembly and commissioning 10 Mio. €

design, engineering, consulting, miscellaneous 5 Mio. €

Total 99 Mio. €

Operation and maintenance costs 1.5 Mio. €/a

Power generation costs 0.13 €/kWh

Operation costs. Annual operation costs comprising the costs for operation and
maintenance are estimated at 50 €/kW. In the present case, this corresponds to
costs of approximately 8.6 €/m 2 of mirror surface and year (Table 5.4). For the