Using the wind to create electricity 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 big coal power plant.
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, power companies build "wind farms" with dozens of huge wind turbines.
Wind farms are built in flat, open areas where the wind blows at least 14 miles per hour. Iowa currently has more than 600 wind turbines, producing enough electricity to power 140,000 homes. Minnesota and Wisconsin are also home to wind farms – and the number is growing every day.
Some schools in the Midwest have their own wind farms! In Spirit Lake, Iowa, the school playground is right underneath two wind turbines. When it comes to size, bigger is better – the bigger the wind turbine, the more wind it reaches and the more electricity it produces.
The turbines at Flying Cloud Wind Plant in northwest Iowa are about 240 feet tall. The largest wind turbine in the world, located in Hawaii, stands 20 stories tall and has blades the length of a football field!
The tower is usually hollow and made of steel. The blades, called rotors, are made of fiberglass and polyester
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