The United States has long used hydropower, which is now the country’s largest source of renewable energy, for electricity production. Hydropower contributed 27 percent of total U.S. utility-scale renewable electricity generation and 5.86 percent of total utility-scale electricity production in 2024. The U.S. first started developing its hydropower fleet in the late 1800s, long before other renewable energy sources, such as wind and solar power. Hydropower plants produce electricity using the elevation difference created by a dam or…