How it works
Hydropower uses the kinetic energy of moving surface water from rivers and oceans. Turbines and generators trap and convert water’s energy into electricity, which is then contributed to nearby power grids or battery packs for storage.


  • Hydropower doesn’t contribute to greenhouse gas emissions, and it is endlessly renewable.
  • It’s becoming easier for households to benefit from water energy, with newly developed small and micro-hydropower systems.


  • Dams at large hydropower plants have been known to harm fish and wildlife populations.
  • Water availability in certain locations may vary substantially due to climate changes.
  • Developing wave and tidal power technology is still not economically feasible in the United States.

Hydropower facilities often create reservoirs that can help control floods, supply water to communities, and provide recreation areas.

Best choice for …
those who live near moving water, or near large hydroelectric power sources that produce energy they can buy from their utility company.

Approximate cost
Small and microhydropower systems range from $600 to $4,500. Like other renewable-energy options, consumers can often opt to purchase hydroelectricity from their local utility company.

To obtain permits and water rights for home systems, the DOE recommends first contacting your county engineer. You may also need to contact the Federal Energy Regulatory Commission (; 866.208.3372) and the U.S. Army Corps of Engineers (; 202.761.0011).