Geothermal Power Explained

National Renewable Energy Laboratory (NREL) Energy Basics: Geothermal (Click to watch, 2:45)

How is electricity generated at a geothermal power plant? Water is heated into steam, which turns a turbine connected to a generator. The generator converts the mechanical energy of the spinning turbine into electrical energy that can be transmitted to homes and buildings through transmission lines. In a geothermal power plant, energy comes from heat that is already present below the Earth’s surface. Geothermal energy is a good energy option in places where there is hot magma close to the Earth’s surface that naturally heats water in the ground into steam. In such places, geothermal energy is a constant and reliable source of energy. (Union of Concerned Scientists)

Interesting Geothermal Power Facts:

  • The United States generates more electricity through geothermal energy than any other country in the world. The leading state — California — generates 79 percent of the nation’s geothermal electricity. (Department of Energy)
  • The Geysers, located in the Mayacamas Mountains about 30 miles north of Santa Rosa, California, is the biggest geothermal energy plant in the world. It’s capable of producing 725 megawatts, enough electricity to power 725,000 homes, and emits no greenhouse gases. (Yale Climate Connections)
  • Geothermal water can be used for heating homes and offices, growing plants in greenhouses and some cities pipe geothermal water under roads to melt snow. (National Geographic)
The Nesjavellir Geothermal Power Plant in Iceland. Photo by: Gretar Ívarsson

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