Electric power from solar energy

In spite of the free by available energy, the generation of electricity directly from 'sunlight' is a very costly matter. In order to compete with usual methods, the efficiency must be considerably increased, and the solar cells must become cheaper. In the present article, the progress made so far and the future development aspects of both of these points are examined. The author concludes that in the near future, energy sources on a solar basis seem only justified for particular purposes. However, the picture may change as a result of the present research activities. (orig./LH)