Cost-Effective Power from Sustainable Energy Sources

Through worldwide installation of solar-thermal power plants, the cost of solar power will be reduced at a progress ratio of 85 to 90 % each time the installed capacity doubles, due to learning and rationalization effects [7]. Here an ex­ample: A solar thermal power plant at present, depending on the insolation at its site, can generate power for 0.15 to

0. 20 €2000/kWh, assuming a capital interest of 6.5 % per year and a plant lifetime of 25 years. With 10,000 MW installed power capacity worldwide, this cost would decrease to around 0.80 to 0.10 €2000/kWh, and with 100,000 MW in­stalled capacity, to 0.04 to 0.06 €2000/kWh. Similar learning curves can be observed for all of the sustainable technolo­gies.

A cost reduction of this order would be achieved for an assumed expansion of solar-thermal generating capacity from today’s 1000 MW to about 40,000 MW in the year 2020 and 240,000 MW by 2030, including the capacity needed for desalination of seawater. Current scenarios even assume notably faster growth rates for solar-thermal in­stalled capacity. In the long term, an overall capacity of 500 to 1000 GW could be installed worldwide by 2050. All the costs quoted above are in constant (year 2000) Euro values,

1. e. without inflation.

As soon as the point of cost equality with convention­al power generating sources has been reached, sustainable sources would grow more quickly, thus avoiding further ris­es in national electric power costs. In this manner, the pow­er cost of the energy mixture could be held constant, in some cases even reduced to an earlier level, by increasing the fraction of power from sustainable sources. This con­cept can be implemented in all the EU-MENA countries. The present continual escalation of power costs shows clearly that the broad-based introduction of sustainable en­ergy sources offers the only possibility of avoiding further cost increases in the energy sector on a long term basis, and of returning to a relatively low level of electric power costs in the medium term.