The history of wind

Throughout history, people have harnessed the wind in many ways. Over 5,000 years ago, the ancient Egyptians used wind power to sail their ships on the Nile River. Later, people built windmills to grind their grain. The earliest known windmills were in Persia (Iran). These early windmills looked like large paddle wheels.

Centuries later, the people of Holland improved the basic design of the windmill. They gave it propeller-type blades made of fabric sails and invented ways for the windmill to change direction so that it could continually face the wind. Windmills helped Holland become one of the world's most industrialized countries by the seventeenth century.

American colonists used windmills to grind wheat and corn, pump water, and cut wood. As late as the 1920s, Americans used small windmills to generate electricity in rural areas without electric service. When power lines began to transport electricity to rural areas in the 1930s, local windmills were used less and less, though they can still be seen on some ranches in the West.

Wind power plants

Wind power plants, sometimes called wind farms, are clusters of wind machines used to produce electricity. A wind farm usually has dozens of wind machines scattered over a large area.

Wind plants need a lot of land. One wind machine needs about two acres of land to call its own. A wind power plant takes up hundreds of acres. On the plus side, farmers can grow crops or graze cattle around the machines once they have been installed.

Wind resources

Where is the best place to build a wind plant? There are many good sites for wind plants in the United States. Because of the availability of consistent wind, some companies are considering installing wind machines offshore. As a rule, wind speed increases with altitude and over open areas with no windbreaks. Good sites for wind plants are the tops of smooth, rounded hills, open plains or shorelines, and mountain gaps that produce wind funneling.

Wind speed varies throughout the country. It also varies from season to season. In Tehachapi, California, the wind blows more from April through October than it does in the winter. This is because of the extreme heating of the Mojave Desert during the summer months. The hot air over the desert rises and the cooler, denser air above the Pacific Ocean rushes through the Tehachapi mountain pass to take its place. On the other hand, in a state like Montana, the wind blows more during the winter.

These seasonal variations are a good match for the electricity demands of the regions. In California, people use more electricity during the summer when air conditioners are used for cooling. Conversely, more people use electricity in Montana during winter months for heating.

One wind machine can produce enough electricity for 150 to 400 homes per year. In this country, wind machines produce about 0.1 percent of the nation's electricity—a very small amount. But it is enough electricity to serve one million households, which is about the size of Chicago, Illinois.

Wind energy offers a viable, economical alternative to conventional power plants in many areas of the country. Wind is a clean fuel; wind farms produce no air or water pollution because no fuel is burned.

The most serious environmental drawbacks to wind machines may be their negative effect on wild bird populations and the visual impact on the landscape. To some, the glistening blades of windmills on the horizon are an eyesore; to others, they are a beautiful alternative to conventional power plants.¹

Footnotes

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