Geothermics (geothermal prospecting) is the use of the earth's heat to produce electricity, heat and cooling energy. Temperatures inside the earth heat the planet’s outer layers and underground water reservoirs. This energy is tapped with the help of wells.
For using geothermal energy up to 400 metres deep
("near-surface"), a heat probe combined with a heat pump utilises the
different temperature level between the soil and the ambient air. Number of facilities (such as geothermal probes or collectors in combination with heat pumps): over 470,000 with approximately 4,700 installations. In deeper
strata (>400m), hot water and steam are obtained for district heating grids or to
generate electricity. In Germany, there are 42 plants, with a total installed heat capacity of approximately 417 MW.