Geothermal energy is harvested by drilling into underground reservoirs of steam or water heated by the Earth. While western states like California and Nevada lead the country in geothermal energy production, emerging technologies may make it possible to extract geothermal energy throughout the United States.
Geothermal energy comes from the heat of the Earth’s interior. Reservoirs of steam or hot water with temperatures higher than about 225°F can generate electricity, while lower-temperature geothermal fluids are often used directly for heating and other applications. In western states like California and Nevada, hot rocks beneath the Earth’s surface create shallow hot water reservoirs. Scientists are developing enhanced geothermal systems to extract heat from hot, dry rocks in order to produce electricity. Read more