The wind is renewable energy because it never stops blowing! It flows around the planet pushed on by the uneven heating and cooling of the earth's surface. It is an endless supply of power, if only we can harness it.

As soon as humans took to the ocean in boats they began using wind power for sailing. Then farmers fastened early wind turbines into windmills. They used them to grind grain and pull up water from wells. Even early lumber mills were powered by windmills. In the early 1900s, when electricity had not made it out to rural ranches in the American west, ranchers put up small windmills to generate their own electricity.

Nowadays wind energy is mostly used for making electricity. The turning blades power a generator that turns the mechanical power into electricity. Modern windmills are called wind machines, and they are huge. One wind machine can be as tall as a twenty-story building with three blades that are 200 feet long. They are placed in wide-open areas, often near the coasts where the wind blows a lot of the time.

On the Right Track

United Parcel Service saved a huge amount of energy by changing how they deliver packages in big cities. To find out what they did, put each letter in its proper place in the grid. The letters all fit in spaces under their own column, but maybe not in the same order! We left some letters to get you started.

More and more states are starting to make wind farms to help supply people with the electricity they need. The state of California makes more than twice as much wind power as any other of the thirty states using it. But they only work when the wind is blowing!

Because of the wind stirred up off the ocean, many wind farms are being planned for offshore sites. The first offshore wind farm in the United States is planned for off the coast of Cape Cod, Massachusetts. According to wind power experts, each windmill will be able to make up to 4 million kilowatt hours (kWh) of electricity per year. That will supply up to 400 homes.

Wind farms with dozens of wind machines can make electricity for entire communities. A wind farm in Texas has 46 wind machines that make enough electricity for 7,300 homes. Wind farms are usually owned by people or businesses, which then sell the power to public power companies. In the United States today, wind machines are making enough electricity to supply about 1.6 million homes. That may sound like a lot but in a country as big as ours, it is still less than 1 percent of the people. It is growing over time though. In just the last ten years, the amount of wind power has grown 300 percent.