Clean Energy Primer: Geothermal
The United States is continuing to diversify its renewable energy sources, including a recent commitment to research and development in geothermal energy. Geothermal energy is a clean and renewable energy source that uses the heat of the Earth. It is growing rapidly in the U.S. and globally, with tremendous economic benefits and a bright future.
Geothermal energy exists in naturally occurring underground reservoirs. These reservoirs reach temperatures from 200-700oF. The most common reservoirs include volcanoes, fumaroles, hot springs, and geysers.
Energy produced from geothermal reservoirs can be used directly in heating and cooling, as electricity for power plants, and in geothermal heat pumps. This renewable source also provides power for the agriculture, aquaculture, and industrial industries and fuel for snow-melting, greenhouses, and food preparation.
Across the world, 29 countries are taking advantage of this renewable source, with fifty more in development. The United States is a global leader in geothermal energy. Reservoirs are most popular in the western states and in Hawaii, where reservoirs are naturally located. Conventional geothermal reservoirs across seven western states produce over 16 billion kWh of energy in geothermal power plants.
Geothermal energy has been on the map since the 1900’s, when the City of Klamath Falls, Oregon, used hot spring water to provide heating in homes. California is currently the leading state in geothermal generation. It has produced electricity from the Geyser’s Dry Steam Reservoir since the 1960’s.
But conventional reservoirs occurring in Oregon and California are geographically limited. The Department of Energy recently designated Utah’s Frontier Observatory for Research in Geothermal Energy as a site for research and development in enhanced or manmade geothermal systems and reservoirs. An Enhanced Geothermal System (EGS) will create opportunities to increase energy production across the country by removing the locational barriers of conventional reservoirs.
At the end of 2019, geothermal energy boasted a total installed power generation capacity of 15,400 MW. Experts predict that this capacity could reach 28,000 MW in the next 15-20 years. And the United States is the key growth market, with significant opportunities in heating and cooling specifically.
No power plants or pumps are needed to directly provide geothermal energy in residential or commercial buildings. By using naturally occurring heat under the earth’s surface, geothermal energy has high potential to decarbonize the energy sector.