Geothermal energy (terrestrial heat) is the heat energy stored beneath the surface of the earth. The heat stored in the earth is available around the clock, does not depend on weather or seasons and is thus suitable for meeting base load requirements. The technologies so far developed offer flexible methods of using this energy for heating, cooling and generating electricity:
- Near-surface geothermal energy: Provides heating, cooling or hot water, for example, in multi-family homes
- Deep geothermal energy: Electricity generation in power plants and/or use of heat in heating plants in conjunction with district heating systems.
The potential of geothermal energy can be used practically everywhere. In countries such as Germany, Italy, Indonesia, the Philippines, Mexico, the USA and Iceland, the use of geothermal energy for heating and electricity generation has been part of the energy concept for many years. In 2012, 223 TWh of renewable energy from geothermal sources was extracted worldwide, 2/3 of which was for heating and 1/3 for electricity generation.
The German geothermal energy industry covers the entire range of geothermal technologies: From deep geothermal energy, both hydrothermal and petrothermal, for heating, cooling and electricity generation up to near-surface geothermal energy which makes use of the heat in the topmost layers of the earth or in the groundwater.