What is Hydropower?

Hydropower, also known as hydroelectric power, is the process of using water to capture energy that can be converted to electricity. According to information from the National Hydropower Association, the US hydropower fleet includes 2,270 active power plants. Hydropower provides energy to over 30 million American homes.[1]

According to the US Energy Information Administration (EIA), there are conventional hydropower facilities in almost every state (every state except for Mississippi)..[2] The three main federal agencies authorized by Congress to own and operate hydropower include the US Army Corps of Engineers, the Bureau of Reclamation, and the Tennessee Valley Authority (TVA).[3] Total US conventional hydroelectricity generation capacity was approximately 80,027 MW, as of 2021.[4] The top five states--and their share of total US conventional hydroelectricity generation capacity in 2021--are listed below:

  • Washington (27%)
  • California (13%)
  • Oregon (10%)
  • New York (6%)
  • Alabama (4%)[5]

In 2021, there was about 23,022 MW of total pumped-storage hydroelectric generating capacity in 18 states. Five states (California, Virginia, South Carolina, Michigan, and Georgia) accounted for a combined 61% of the national total.[6]

In addition to conventional hydroelectric power sources, the Department of Energy has also funded projects to accelerate wave, tidal, and current project deployments and the development of the marine and hydrokinetic energy market, in general. These technologies convert wave motion—such as free-flowing ocean, tidal, and river currents—into energy. While these technologies are at an earlier stage of development (compared to conventional hydropower), they are expected to offer significant promise for adding to the renewable energy portfolio in the United States.[7]

In April 2019, the Department of Energy published a report titled Powering the Blue Economy: Exploring Opportunities for Marine Renewable Energy in Maritime Markets, in which the Water Power Technologies Office looks for marine and coastal opportunities for marine energy to be used. The potential applications for marine energy fall into two areas: power at sea and resilient coastal communities. The following are the markets that fall under each area.

Power at Sea

  • Ocean observation and navigation
  • Charging underwater vehicles
  • Marine aquaculture
  • Marine algae farming
  • Seawater mining

Resilient Coastal Communities

    • Seawater desalination
    • Coastal resiliency and disaster recovery
    • Community-scale isolated power systems: community microgrids[8]

Updated by Erin Bennett, June 2022