Wind turbines that are used to generate electricity come in many shapes and sizes.
The largest turbine, in Hawaii, is 20 stories high and has propellers with a span longer than a football field.
It can produce enough electricity to power 1,400 homes.
Smaller machines have blades between 8 and 25 feet (2.4 and 7.6 m) in diameter mounted on towers up to 30 feet (9 m) high.
The world’s largest wind generation plant, with 470 windmills, is on the Washington-Oregon border, overlooking the Columbia River.
Wind generation plants are also known as wind farms.