I. Introduction - Wind TurbinesWind is the movement of air from an area of ​​high pressure to an area of ​​low pressure. Wind is also a clean source of renewable energy that produces no air or water pollution. Wind exists because the sun unevenly heats the surface, and as warm air rises, cooler air moves in to fill the void. So, as long as the sun shines, the wind will blow and people will use it to power their lives. Over the last ten years, wind energy has increased by 25% per year and yet provides only a small part of the world's energy. Most wind energy comes from turbines that can be nearly as tall as a 20-story building and have blades 3,200 feet long. The wind spins the blades, which spin a shaft connected to the generator which makes these blades look like giant airplane propellers on a big stick. Some other turbines work the same way, but the turbine is on a vertical axis and the blades look like a giant eggbeater. These turbines are well known in the world as wind turbines.II. WindmillsWind turbines were initially known as windmills. Windmills were invented by the Persians between 500 and 900 AD. They were vertical style windmills with sails that turned the shaft connected directly to a grindstone or pump and were used to grind sand. There were also wind pumps, developed in China around 200 BC and used to pump water from underground wells. Traders and traders who traveled to Asia brought these ideas to Europe, where they spread. There were many types of windmills. There were post mills, invented by Europeans and these windmills had a horizontal axis which helped the sails make better use of the wind. There were also gown factories, which were later invented… middle of paper… houses. The country with the largest installed wind capacity is Germany, followed by Spain, the United States, India and Denmark. The locations of wind turbines vary. For example, countries like Denmark, which produce a tenth of their electricity through wind energy, have a significant green commitment. They are choosing to develop wind energy because they see it as an environmentally friendly option. Some countries, like Spain, have a reliable source of wind energy because they have constant winds directly from the Atlantic Ocean. Wind turbines are also being built in countries like India, because wind energy is a cost-effective alternative to extending the grid into remote or underdeveloped areas. So, with growth like this, experts say that if these growths continue, by 2050 the answer to a third of the world's electricity needs will be found in wind..