Name: Geothermal Energy or Geothermal Power.
Description: Geothermal Energy is produced from the heat within the Earth. The word "geothermal" comes from the Greek words geo, meaning earth," and therme, meaning, "heat." We use geothermal energy to produce electricity. The geothermal energy works by using hot rocks underground which heat water to produce steam. We drill holes down to the hot region, steam comes up, is purified and used to drive turbines, which drive electric generators. .
Using geothermal energy to produce electricity is a relatively new industry. It was initiated by a group of Italians who built an electric generator at Lardarello in 1904. The first attempt to develop geothermal power in the United States came in 1922 at The Geysers steam field in northern California. The project failed because the pipes and turbines could not stand up to the corrosion of the particles that were in the steam. There are four main kinds of geothermal resources: hydrothermal, geopressured, hot dry rock, and magma. Today hydrothermal resources are the only kind in wide use. The other three resources are still in the early stages of development. Hydrothermal resources have the common ingredients of water (hydro) and heat (thermal). These geothermal reservoirs of steam or hot water occur naturally where magma comes close enough to the surface to heat ground water trapped in fractured rocks. Hydrothermal resources are used for different energy purposes depending on their temperature and how deep they are. We find most of the geothermal energy in volcanoes and hot springs. Usually geothermal energy is deep underground. There may be no clues above ground to what exists below ground. Geologists use many methods to find geothermal resources. They may study aerial photographs and geological maps. They may analyse the chemistry of local water sources and the concentration of metals in the soil. They may measure variations in gravity and magnetic fields.