Geothermal Power Plants in the World

• Geothermal power is a clean alternative to burning fossil fuel. VisionsofAmerica/Joe Sohm/Digital Vision/Getty Images

  Geothermal power plants use the Earth's natural heat to drive turbines and generate electricity. Cleaner than traditional fossil fuel-powered plants, geothermal energy's main byproduct is steam, which at some plants is used to heat nearby buildings. The world's first geothermal power plant opened in Italy in 1904 and now there are more than 50 such plants around the globe.

USA - Raft River

• Raft River, Idaho, is one of 12 binary cycle plants in the U.S. and was the first of this type of geothermal power plant in the world. Binary cycle power plants utilize water to boil a secondary liquid, with a lower boiling point than water, to drive the electricity-generating turbines. Drilling down to depths of up to 6,000 feet to reach groundwater with temperatures of up to 300 degrees F, Raft River is thought to be capable of producing 110 megawatts of power.

Iceland - Nesjavellir

• Nesjavellir produces both electricity and hot water to power and heat buildings in the surrounding area. Iceland sits on top of the mid-Atlantic ridge, a fissure in the Earth's crust that allows hot magma to rise very close and sometimes up through the surface. As one of the largest geothermal power plants in the world, Nesjavellir attracts over 15,000 tourists to its site every year.

Kenya - Olkaria II

• The largest of Africa's geothermal power plants, Olkaria II supplies electricity to Nairobi and the town of Olkaria itself. Bore holes extract heated water and steam from deep beneath Africa's Rift Valley to produce 150 megawatts of power. The plant, operated by the Kenya Electricity Generating Company, was partly financed by the World Bank.

Russia - Mutnovsky

• Fully operational since 2002, the Mutnovsky Geothermal Power Plant produces 50 megawatts of electricity from the Mutnovsky steam field and is the largest geothermal power plant in Russia. Situated in eastern Russia, the field has been under exploration for over 20 years and contains over 90 wells. Power generated by the plant is carried 90 kilometers to the Avacha substation and then distributed throughout the Kamchatka electricity grid.