The US Department of Energy (DOE) and its Oak Ridge National Laboratory have released a renewable energy resource assessment that estimates over 65GW of new hydroelectric power capacity could be developed across more than three million rivers and streams in the country.

Hydroelectric power currently makes up 7% of total electrical generation in the US and continues to be its largest source of renewable energy, reducing more than 200 million metric tons of carbon emissions a year.

The DOE’s current assessment builds on recent advancements in geospatial datasets and represents the most detailed evaluation of US hydropower potential at undeveloped streams and rivers to date.

The DOE said the study also assesses technical, socioeconomic and environmental characteristics that will help energy developers, policymakers and local communities identify the most promising locations for sustainable hydropower facilities.

Stream- and river-specific information on local wildlife habitats, protected lands, water use and quality and fishing access areas are also included in the assessment.

Alaska, California, Colorado, Idaho, Montana, Oregon and Washington led the US in greatest hydropower potential, while Kansas, Missouri, Pennsylvania and Wyoming led the country in new stream-reach hydropower potential.

The report, titled the New Stream-reach Development Assessment, builds on a previous assessment that identified more than 12 GW of hydroelectric potential at the country’s 80,000 existing non-powered dams.

US Energy Secretary Ernest Moniz said, "The United States has tremendous untapped clean energy resources and responsible development will help pave the way to a cleaner, more sustainable and diverse energy portfolio."

"As the Energy Department works with industry, universities and state and local governments to advance innovative hydropower technologies, the resource assessment released today provides unparalleled insight into new hydropower opportunities throughout the country," Moniz said.