A new report released today by the Energy Department analyzes the potential to generate clean hydroelectric energy at existing dams across the United States. Harnessing the tremendous power of the nation’s waterways could help increase the supply of clean energy for American families and businesses.

Thousands of dams across the country are not currently equipped to produce power. Today’s report finds that if fully developed, these existing dams could provide an electrical generating capacity of more than 12 gigawatts (GW). This amounts to increasing existing U.S. conventional hydropower capacity by roughly 15%.

The majority of potential resides in the country’s workhorse waterways – like the Ohio, Mississippi, Alabama, and Arkansas rivers. Eight GW of capacity is concentrated in just 100 facilities, 81 of which are owned and operated by the U.S. Army Corps of Engineers.

The report, titled An Assessment of Energy Potential at Non-Powered Dams in the United States, analyzes more than 54,000 specific sites that could be developed to generate power. The results indicate that, if fully developed, the nation’s non-powered dams could provide enough energy to power over four million households.

It was funded by the Office of Energy Efficiency and Renewable Energy and produced by Oak Ridge National Laboratory in partnership with Idaho National Laboratory.

This study is one of a number of nationwide resource assessments being conducted by the Energy Department. The preliminary results indicate that by 2030, 15% of the nation’s electricity could come from water power – including hydropower and marine and hydrokinetic energy sources, like waves and tides.