Geothermal power is the use of earth’s heat to generate electricity. Geothermal comes from the Greek words geo, meaning earth, and therme, meaning heat. Geothermal literally means “earth heat”.

Geothermal-generated electricity was first produced at Larderello, Italy, in 1904. 

Geothermal energy is used in many places today including California and Nevada. Geothermal energy has a huge potential for producing electricity. About 8,000 megawatts (MW) of geothermal electricity are currently produced around the world, including about 2,800 MW of capacity in the United States. Today’s technology produces geothermal electricity by using hydrothermal resources. Hydrothermal is the use of water/steam resources.

In the future we may be able to use the heat of the deep hot and dry rock formations contained in the earth’s crust. Later we could possibly even use the even deeper, almost unlimited, energy found in the Earth’s magma.

Steam plants use very hot (more than 300° F) steam and hot water resources. The steam comes directly from the resource or the hot high-pressure water which is then depressurized to produce steam. The steam then turns turbines, which drive generators that generate electricity. The only significant waste release from these plants is steam. Small amounts of carbon dioxide, nitric oxide, and sulfur are also released in this process. This is almost 50 times less pollution than at traditional coal power plants.