Renewable energy comes from sources that are not depleted when used. These resources include geothermal, solar, wind, water, and biomass. All constitute growing sources of environmentally sustainable energy to meet the country’s electricity needs. Explore production data.
Geothermal energy comes from the earth’s heat, which is captured as steam or hot water and converted into energy. Most geothermal resources are found along the boundaries of tectonic plates and manifest themselves as volcanoes, hot springs, or geysers. The U.S. is the largest producer of geothermal energy and California produces more than any other state.
Many sites for potential geothermal development are on federal land. The Bureau of Land Management (BLM) has the authority to manage geothermal leasing on 240 million acres of public land. Advances in extraction methods and technology could result in new sources of geothermal energy.
See where geothermal energy production happens.
Solar energy can be generated in two ways: by converting solar radiation into heat and electricity via photovoltaic panels or by using the sun’s radiation to heat a fluid and produce steam for a power generator. California leads the country in producing solar energy, producing 56% of the nation's solar energy in 2015, followed by Arizona, which produced 13%. As of 2014, California is the first state to receive 5% or more of its electricity from solar energy sources.
The solar industry has experienced rapid growth in the past decade due to government programs such as tax credits and state renewable portfolio standards, increased public awareness of its environmental benefits, and decreasing technology costs. Manufacturing costs for solar panels have decreased, and private industry has created better batteries to store solar energy. In southwestern states, solar radiation levels are some of the best in the world for solar energy production.
Wind power takes advantage of daily wind cycles to rotate wind turbines, which can be clustered together on wind farms. In 2013, wind power accounted for 2% of total U.S. energy production. Texas (44.9 GW hours), Iowa (17.9 GW hours), Oklahoma (14 GW hours), and California (12.3 GW hours) are leading producers.
No offshore wind projects have been completed to date. The National Renewable Energy Laboratory estimated in 2012 that there is enough wind energy potential offshore to generate four times the electricity held by the U.S. power grid. While wind speeds off the Atlantic Coast and in the Gulf of Mexico are lower than in the Pacific, the presence of shallower waters in the Atlantic makes developing wind projects there more affordable in the short term. To date, the Bureau of Ocean Energy Management (BOEM) has issued nine commercial wind energy leases on the Atlantic Outer Continental Shelf, including those offshore of Delaware, Maryland, Massachusetts, Rhode Island, and Virginia. BOEM expects to hold lease sales for areas offshore of New Jersey and North Carolina in the near future and is considering a number of other commercial wind energy planning areas.
Hydroelectric energy is the country’s oldest and largest source of renewable energy, supplying 10% of U.S. electricity generation from 1950-2015.
Hydroelectric technologies capture the power of flowing water and turn it into electricity. The most common type of hydroelectric power plants are dams that store water in reservoirs. Water released from the reservoir spins a turbine, which in turn activates a generator to produce electricity.
Washington leads in hydroelectric energy, producing 29% of the nation's hydroelectric energy in 2015.
The Bureau of Reclamation, responsible for managing, developing, and protecting water sources is the second largest producer of hydroelectric power. The Bureau's 53 powerplants bring water to more than 31 million people. Today, it's the largest wholesaler of water in the country.
Biomass is an organic renewable energy source that includes materials such as algae, wood chips, and agriculture residue. These materials contain stored energy from the sun created by photosynthesis, and burning them releases chemical energy. Biomass-fired power plants produce electricity by burning biomass to heat water to a high temperature under pressure. The result is steam that powers turbines and connects to generators.