Potentials and Limits of Renewable Sources of Energy

Although renewable energies have a good image among the public, their market penetration is still very low. Therefore this paper first analyses the economic and physical constraints. Then the basic requirements for new energy options are discussed. Important technologies such as solar heaters, photovoltaic cells, wind turbines and biomass converters are briefly characterized with regard to the current state of the art, economic competitiveness and positive and negative environmental effects. Emphasis has been put on CO₂ reduction potentials. The figures presented refer to the geographical region of Central Europe and Germany.