WINDMILL

A?wind turbine?is a windmill-like structure specifically developed to generate electricity. They can be seen as the next step in the development of the windmill. The first wind turbines were built by the end of the nineteenth century by?James Blyth?in?Scotland?(1887),[42]?Charles F. Brush?in?Cleveland, Ohio?(1887–1888)[43][44]?and?Poul la Cour?in Denmark (1890s). La Cour's mill from 1896 later became the local power of the village of Askov. By 1908 there were 72 wind-driven electric generators in Denmark, ranging from 5 to 25?kW. By the 1930s, windmills were widely used to generate electricity on farms in the United States where distribution systems had not yet been installed, built by companies such as?Jacobs Wind, Wincharger, Miller Airlite, Universal Aeroelectric, Paris-Dunn, Airline, and Winpower. The Dunlite Corporation produced turbines for similar locations in Australia.[citation needed]

Forerunners of modern horizontal-axis utility-scale wind generators were the WIME-3D in service in?Balaklava?USSR?from 1931 until 1942, a 100-kW generator on a 30-m (100-ft) tower,[45]?the?Smith–Putnam wind turbine?built in 1941 on the mountain known as Grandpa's Knob in?Castleton, Vermont, United States of 1.25 MW[46]?and the?NASA wind turbines?developed from 1974 through the mid-1980s. The development of these 13 experimental wind turbines pioneered many of the?wind turbine design?technologies in use today, including steel tube towers, variable-speed generators, composite blade materials, and partial-span pitch control, as well as aerodynamic, structural, and acoustic engineering design capabilities. The modern?wind power industry?began in 1979 with the serial production of wind turbines by Danish manufacturers Kuriant,?Vestas,?Nordtank, and?Bonus. These early turbines were small by today's standards, with capacities of 20–30?kW each. Since then, commercial turbines have increased greatly in size, with the?Enercon E-126?capable of delivering up to 7 MW, while wind turbine production has expanded to many countries.[citation needed]

As the 21st century began, rising concerns over?energy security,?global warming, and eventual?fossil fuel depletion?led to an expansion of interest in all available forms of?renewable energy. Worldwide, many thousands of wind turbines are now operating, with a total?nameplate capacity?of 591?GW as of 2018.[47]

Materials[edit]

Main article:?Wind turbine design