windmills

my name is Samuel James Harris

1)Windmilla machine that uses the energy of the wind to produce power.At least since the middle ages windmill have been used to mechanical power for such as grinding grain or pumping water for irrigation.

2)A windmill is a machine that harnesses the power of the wind. Windmills may be used to grind grain into flour, to pump water, or to produce electricity.

A windmill has a number of blades that spin around when wind blows on them. The blades are mounted on a tall tower or building. They are connected to a vertical shaft, or rod. When the blades spin, they turn the shaft. The turning shaft powers a device that does work—for example, a water pump or millstones, which grind grain. The shaft also may provide power to a machine called a generator, which produces electricity.

People in western Asia built the earliest known windmills more than 1,000 years ago. They used these windmills to grind grain. Windmills spread to Europe by the 1100s. The Dutch used them to pump water out of low-lying areas near the sea. By the 1800s, however, many people used steam engines rather than wind power to run mills and to do other work.

Today modern windmills, called wind turbines, produce electricity for many communities. A group of wind turbines working together is called a wind farm.

FROM BRITANNICA

3)History of Wind Energy

The first windmills were used for irrigation in Persia in the 5th century A.D. The technology spread to Europe by the 12th century. Early European windmills pumped water or turned the grindstones of mills used to produce flour from various grains. In Holland, for example, windmills were used to pump water to drain wetlands behind newly constructed dikes. The land was then converted to farmland. Dutch windmills became symbols of this tiny country.

During the late 19th century thousands of windmills were built in Europe and the rural United States. Most of these pumped irrigation water. As the technology developed, however, windmills also began to be used to generate electricity. During the 1930s many thousands of small farms in the United States, most of them in the Great Plains, relied on windmills for livestock watering and electrical production. Rural windmills were slowly but steadily replaced, however, by grid power: electricity delivered from centralized power plants via long-distance transmission lines installed during a massive rural electrification program from the 1930s to the 1950s (see Public Works Administration).

Two devastating oil embargoes (see petroleum industry) in the 1970s caused a sharp rise in oil prices. Interest in alternative energy, including wind, increased in the United States and many other industrialized countries. Private investment and funding for research and development from the U.S. government spurred the development of numerous wind generators for use in homes, farms, and commercial electrical-power production. By the early 1980s more than 30 companies in the United States were manufacturing wind generators for a wide range of uses. Several wind farms of more than 100 large machines were established in California. They soon began generating hundreds of megawatts of electrical energy.

from grolier online

4)History of Wind Energy

The first windmills were used for irrigation in Persia in the 5th century A.D. The technology spread to Europe by the 12th century. Early European windmills pumped water or turned the grindstones of mills used to produce flour from various grains. In Holland, for example, windmills were used to pump water to drain wetlands behind newly constructed dikes. The land was then converted to farmland. Dutch windmills became symbols of this tiny country.

During the late 19th century thousands of windmills were built in Europe and the rural United States. Most of these pumped irrigation water. As the technology developed, however, windmills also began to be used to generate electricity. During the 1930s many thousands of small farms in the United States, most of them in the Great Plains, relied on windmills for livestock watering and electrical production. Rural windmills were slowly but steadily replaced, however, by grid power: electricity delivered from centralized power plants via long-distance transmission lines installed during a massive rural electrification program from the 1930s to the 1950s (see Public Works Administration).

Two devastating oil embargoes (see petroleum industry) in the 1970s caused a sharp rise in oil prices. Interest in alternative energy, including wind, increased in the United States and many other industrialized countries. Private investment and funding for research and development from the U.S. government spurred the development of numerous wind generators for use in homes, farms, and commercial electrical-power production. By the early 1980s more than 30 companies in the United States were manufacturing wind generators for a wide range of uses. Several wind farms of more than 100 large machines were established in California. They soon began generating hundreds of megawatts of electrical energy.Tower Mill.

The tower mill was invented in Europe early in the 15th century. It had a stone or brick tower and a timber roof, or cap, that contained the shaft on which the sails revolved. The sails were faced into the wind by rotating the entire cap on a circular wooden track or, later, on wooden or metal rollers. This was done by the miller, who moved a tail pole connected to the cap. Some of the finest tower mills were built in Holland, where many still stand. They survived in greater numbers than the post mills because their bodies were made of brick or stone rather than of wood.Large-Scale Wind-Powered Systems

Large-scale wind-powered systems are attractive because they do not cause air, water, or thermal pollution; are virtually free of noise when operating; and require little maintenance and no fuel. According to William Heronemus of the University of Massachusetts, wind-powered systems have the greatest chance of being used to supply an important part of the U. S. energy needs in the near future at costs that are competitive with other systems.

To tap wind power on a large scale, Heronemus proposed the erection of 15,000 towers on the Great Plains, spaced as closely as one per square mile (2.6 sq km). Each tower would carry 20 wind turbines, making a total of 300,000. Each wind turbine would consist of a two-bladed propeller with a 50-foot (15-meter) diameter, tip to tip, and each would drive a generator connected to an electrical network. Such an array on the Great Plains could provide the equivalent of an installed capacity of 189,000 megawatts, or nearly half of the total installed capacity of electric power plants in the United States in the mid-1970s.

Heronemus also proposed that large arrays of wind generators be based at sea, where powerful winds provide a good source of power.

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