Hydro energy
"Hydro" means "water," so hydro energy is made from water.
But wait! Isn't water and electricity a dangerous combination? Actually, the water never comes in contact with the electricity. The water flowing down a river is used to spin turbines inside a generator and make electricity.
Hydro energy's history
People have used water power for more than 2,000 years. Ancient Egyptians used water wheels for grinding grain, and early Americans used them for sawing wood.
In the 1880s, scientists learned how to use a flowing river to spin the turbines of a generator. The first hydroelectric power plant in the U.S. opened on the Fox River near Appleton, Wisconsin, in 1882.
By the 1940s, nearly half of the electricity in the United States came from hydro power. After World War II, coal power plants became more popular.
Where are hydroelectric plants located?
The Midwest generates the least hydropower of any U.S. region because most of our rivers are small and slow-moving. Alliant Energy operates two hydroelectric dams that are more than 100 years old! This is a picture of our Kilbourn Dam in Wisconsin Dells, Wisconsin. The other one is in Prairie du Sac, Wisconsin.
Most of the big hydroelectric power plants in the United States are in California, Oregon and Washington.
The biggest hydroelectric dam in the United States is the Grand Coulee Dam in Washington. It makes enough electricity for more than two million homes!
Virtual hydro plant tour
Take a walk through a virtual hydro plant and learn more!