Renewable energy sources already account for a significant share of global electricity generation today. In 1997, they contributed nearly 20% to the total production of about 12,000 TWh. This share was almost entirely covered by hydropower, while the contribution from solar thermal energy was very small at 0.7 TWh, even though the first plants for driving irrigation pumps based on solar thermal electricity generation were built at the end of the last century and the beginning of this one. The use of cheaper oil and other fossil fuels prevented further developments at that time, and it was only with the onset of the energy crisis in 1973/74 that these technologies were rediscovered. While the parabolic trough power plants SEGS I-IX with 354 MWel in California have already demonstrated that commercial operation is possible under favorable conditions, for example, parabolic dish power plants also offer potential.