| This article originated from the Critical Issues Program authored by the American Geosciences Institute.
To learn more about AGI or the Critical Issues Program, visit http://www.americangeosciences.org/critical-issues.
Geothermal energy comes from the heat of the Earth’s interior. Reservoirs of steam or hot water with temperatures between 225°-600°F can generate electricity, while lower-temperature geothermal fluids are often used directly for heating, agriculture, and industry. In western states like California and Nevada, magma beneath the Earth’s surface creates shallow hot water reservoirs. Scientists are developing enhanced geothermal systems to extract heat from hot, dry rocks in order to produce electricity.
Why does geothermal matter?
In 2013, only 0.4% of U.S. electricity came from geothermal, but the U.S. Geological Survey estimates that geothermal energy could power more than 10% of the nation’s electricity. While geothermal has historically been limited to western states with shallow hot water reservoirs, enhanced geothermal systems may make it possible to extract geothermal energy from hot, dry rocks throughout the country.
How does geoscience help?
Geoscientists identify geothermal resources and estimate how much energy they can provide, including developing ways to create enhanced geothermal systems. They also investigate the environmental impacts of geothermal energy development and study how to manage existing geothermal systems.
- Geothermal Explained, Energy Information Administration
- An overview of the source of geothermal energy, types of geothermal power plants, locations of geothermal energy, geothermal heat pumps, and brief discussion of geothermal energy and the environment.
- What You Need to Know About Energy: Renewable Sources, The National Academies
- An in-depth overview of the current role of each renewable energy source in the United States, the benefits and disadvantages of each energy source, and opportunities and challenges for using that energy source in the future. (Discusses geothermal, wind, solar, hydroelectric, biomass.)
- Renewable Energy Technology Basics, Department of Energy
- Basic overview of renewable energy technologies for developing biomass, geothermal, hydrogen & fuel cells, hydropower, ocean, solar, and wind energy resources. Also links to Department of Energy research on these technologies.
- What is an Enhanced Geothermal System?
- What are the major sources and users of energy in the United States?
- What is the potential for geothermal energy production in the United States?
- Geothermal Electricity Production Basics, DOE, http://energy.gov/eere/energybasics/articles/geothermal-electricity-production-basics
- How much U.S. electricity is generated from renewable energy?, EIA Energy in Brief, http://www.eia.gov/energy_in_brief/article/renewable_electricity.cfm
- Williams, Colin F., Reed, Marshall J., Mariner, Robert H., DeAngelo, Jacob, Galanis, S. Peter, Jr., 2008, Assessment of moderate- and high-temperature geothermal resources of the United States: U.S. Geological Survey Fact Sheet 2008-3082, 4 p. http://pubs.usgs.gov/fs/2008/3082/
- Geothermal Energy Basics, American Geosciences Institute
- The National Geothermal Data Systems (NGDS) - a catalog of documents and datasets that provide information about geothermal resources
- Hydraulic fracturing
- Nuclear energy
- Oil and gas
- Renewable energy