Geothermal energy is the natural heat of the earth. Thermal energy is continuously generated by the decay of radioactive isotopes of underground rocks and is stored in the earth’s interior. As such geothermal energy is an inexhaustible supply of heat making it one of the forms of renewable energy we have at our disposal.
The temperature at the earth’s core is estimated to be about 4000°C. This drops to 1200°C in the lava of active volcanoes and the temperature of thermal springs is approximately 350°C. Geothermal energy has been used for thousands of years particularly in the case of hot springs. These have been used for localised bathing and cooking as well as for creating bathing complexes such as those built by the Romans in Bath.
Geothermal energy is currently third amongst renewable energy sources for power production in terms of worldwide usage, but there is still an enormous amount of untapped potential. Geothermal heat is classified as low temperature (less than 90°C), moderate temperature (90-150°C) or high temperature (greater than 150°C). Low temperature sources exist everywhere and it is these that the ground source heat pumps tap into. Water is pumped through warm ground to heat or cool buildings and the geothermal energy can also be used to supply buildings with hot water. For more information on ground source heat pumps, Geothermal Energy Ground Source Heat Pumps - Click Here
Geothermal energy can also be used for electricity production whereby a turbine is driven by steam which in turn drives a power generator.
More information on geothermal energy can be found at International Geothermal Association
