What is Pumped-Storage Hydropower?

Music begins to play. The video opens with the scene of an empty whiteboard. An individual is drawing on it. They first write "Energy.gov presents: Pumped-Storage Hydropower." They draw new illustrations as a voice speaks.

They begin with a drawing on white board of earth with oceans filled in in blue.

Water. It's the most important substance on earth. Without it, we wouldn't survive.

Drawing of a water wheel generating power.

It's also helped power our lives for more than a century. More than 6% of our nation's electricity comes from hydropower.

Drawing of solar panel, a house, and a wind turbine feeding into utility lines.

And as wind and solar power continue to grow, water can also play an important role in bringing more renewable resources on to the power grid.

One way is by storing energy through a technology known as pumped-storage hydropower. Think of it as a big battery, flexible enough to respond to various power demands.

When the sun is shining and the wind is blowing, electricity is in high supply, so water is pumped up to higher elevation reservoirs during this time. When the sun goes down or the wind stops blowing, water is released back to lower reservoirs, basically filling in the gaps during peak demand and generating the needed electricity.

Pumped-storage is the most dominant form of energy storage on the electric grid today. There's more than 21 gigawatts of storage capacity already installed in the United States, with future opportunities to more than double that, keeping the grid reliable and ready to add more renewable electricity to the mix at low operating costs.

To learn more about hydropower and pumped-storage, visit our website at water.energy.gov.

Illustrations by Sarah Wagoner. U.S. Department of Energy: Energy Efficiency and Renewable Energy. Like, comment, and share.