Hydropower Quick Facts

Hydropower is renewable. Each year, rain and snow replenish the supply. It’s the nation’s most abundant source of renewable energy.

Hydropower is efficient. Hydropower plants at dams convert about 90% of the energy in falling water into electrical energy. By comparison, fossil-fueled plants lose more than half of the energy content of their fuel as waste heat and gases.

Hydropower is clean. Hydropower produces no emissions. There are
no gases or waste products that contribute to air pollution.

Hydropower is secure. Water from our rivers is largely a domestic resource that is not subject to disruptions from foreign suppliers, cost fluctuations in power markets, international political crises, or transportation outages.

Hydropower is flexible. By adjusting the amount of water flowing through the dams, hydropower can be increased or decreased very quickly to meet the changes in demand for power. This meets a fundamental requirement of all electric grids: demand must always match supply to keep the system stable.

Hydropower allows for the growth of other renewable resources. Hydropower is a great backup for wind and solar power. For example, it can be ramped up to meet demand when the wind isn’t blowing and dialed down during high winds.

Hydropower is affordable. This is because the “fuel” — water — is free, which keeps operating costs low and protects against fluctuations in fuel prices. Over the years, the dams have consistently provided some of the nation’s most affordable electricity.

To learn more about hydropower at bpa.gov.