Wind power has been around for a long time. You've probably seen windmills on farms. When the wind turns the blades of a windmill, it spins a turbine inside a small generator to produce electricity, just like a coal generating station.

A windmill on a farm can make only a small amount of electricity, enough to power a few farm machines. To make enough electricity to serve lots of people, utility companies build wind farms with a large number of wind turbines.

Wind farms are built in flat, open areas where the wind blows at least 14 miles per hour.

They sure are big!

Wind turbines used for large-scale wind farms come in various sizes, but are usually approximately 13 feet wide at the base, and between 230 and 265 feet tall at the hub. With one of the blades in the upright position, the total height is approximately 406 feet, like the one pictured here at Cedar Ridge Wind Farm in Fond du Lac County, Wisconsin.

How many wind turbines do you need to have a wind farm?

Wind farms can have as few as five wind turbines or as many as 150. One of the largest wind farms in the U.S. is in Altamont Pass, California. It has more than 4,800 wind turbines.

Alliant Energy owns and operates three a number of wind farms in Iowa, Minnesota and Wisconsin. In addition to the wind farms owned by Alliant Energy, we also purchase more than 600 megawatts of energy from other wind farms throughout our service area.

How a wind turbine works

A wind turbine works the opposite of a fan. Instead of using electricity to make wind, a turbine uses wind to make electricity.

The wind turns the blades, which spin a shaft, which connects to a generator and makes electricity. The electricity is sent through transmission and distribution lines to a substation, then on to homes, businesses and schools.

Make your own wind-powered gadgets!

Now that you've read about wind power, you can make your own wind-powered gadgets at home.

Renewable Energy Activity

360-degree video: Wind turbine inside and out