| Abstract |
The European market for geothermal heat pumps as well as for underground thermal energy storage for heating, cooling or combined heating/cooling is growing significantly. Positive environmental impact by reduction of CO2 emission and other harmful effluents as well as the uncertain availability of fossil energies influenced this development. In Germany increase of oil and gas prices in 1999 and 2000 combined with special electricity rates for heat pumps have improved the economy of these systems considerably. |