In the voluntary market, customers buy renewable energy in amounts that exceed states' minimum requirements from utility companies. Customers in these programs — also known as utility green power programs — pay their utility a "small premium" to get electricity from renewable sources, according to the U.S. Energy Department. Green power marketing programs Consumers in some states can also opt into "green power marketing programs." watch nowGreen energy programs instead rely on "renewable energy certificates," or RECs. It's a way to provide extra funding to a renewable energy project, typically sold by a broker or marketer rather than a utility, Sumner said.

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Persons: Mark Felix, Jordan Vonderhaar, Jenny Sumner, It's, Joe Raedle, Loren Elliott, —, Sumner, Valerie Macon, Joydeep Mitra, Mitra Organizations: Afp, Getty, U.S . Energy Information Administration, National Renewable Energy Laboratory, Environmental Protection Agency, Roadrunner, Bloomberg, U.S . Department of Energy, Getty Images, U.S . Energy Department, Yale University's, EPA, Michigan State University Locations: Dawson , Texas, U.S, McCamey , Texas, Solano County , California, California , Connecticut, Delaware , Illinois, Maine , Maryland , Massachusetts, Michigan , New Hampshire , New Jersey , New York , Ohio, Pennsylvania, Rhode Island , Texas, Virginia, California, Imperial , California