ABSTRACT
Considerable efforts have been made in the Federal Republic of Germany since the two oil-price crises in 1973 and 1978 to develop renewable energy technologies and to establish them on the market. The motivation for these efforts was the fear of rising costs for fossil fuels due to the international political situation, as well as the concern about the long-term depletion of the reserves of fossil energy. Although the availability of renewable energies in Central Europe is very low, various forms of renewable energies, e.g. water in rivers, wind, solar radiation, biomass and organic gas, are used. Normally, in Germany biogas occurs only in sewage farms and waste dumps, where it is used in cogeneration. There are different definitions of the potential of renewable energies. Frequently, the maximum potential of a utilization is expressed by the technical potential.
