==Brief History of Wind Energy==
Although the use of wind power started around 5000 BC, but electric power generation through wind energy started in 18th century and increasing drastically in 19th and 20th centuries. A brief view on developments on wind power sector are listed below.
[[Image:totalcapacityworld2009.JPEG|thumb|right|400px|Fig 1 '''[http://www.wwindea.org/home/index.php Development of wind power worldwide]''']]
* [http://www.brighthub.com/environment/renewable-energy/articles/71440.aspx 1887] : Prof. James Blyth of Scotland used windmills for generating electricity.
* [http://www.brighthub.com/environment/renewable-energy/articles/71440.aspx 1888] : Charles Brush developed the first wind-powered turbine that generated electricity in the United States based on emulated James Blyth work.
* [http://www.brighthub.com/environment/renewable-energy/articles/71440.aspx 1927] : Joe Jacobs and Marcellus Jacobs improved the wind turbine generator for use in farms.
* [http://www.brighthub.com/environment/renewable-energy/articles/71440.aspx 1931] : development of Darrieus wind turbine. It is a vertical axis turbine that rotates with wind from any direction.
* 1941: Largest mega watt range wind turbine was connected to the local electrical distribution system on the mountain known as Grandpa's Knob in Castleton, Vermont, USA.
* 1971: Denmark installed the first offshore wind farms
* 1990s: More than 2200 MW capacity of wind turbines are installed in california.
* 2003: the largest offshore wind farm North Hoyle was built in the United Kingdom.
* 2003-2010: Research is going is on wind turbines in blades structures, generators, operation and protection, efficiency of wind turbines.
Source:[[Media:windenergy.pdf| Wind Energy]]<br>
The total installed wind power capacity from 2001 to 2010 is shown in fig. 1. All wind turbines installed by the end of year 2009 worldwide are generating 340 TWh per annum.
The country wise share of wind energy by the end of year 2009 is shown in fig. 2.
[[Image:countryshare.JPEG|thumb|center|350px|Fig 2 '''[http://www.wwindea.org/home/index.php Country share of total capacity]''']]
==Working Principle of Wind Turbine ==
Wind is air in motion. It is a form of solar energy. Solar radiation heats every part of the Earth’s surface unevenly due to irregularities and rotation of earth. The flow of wind patterns are modified by the earth's terrain, bodies of water, and vegetative cover. When air moves, causing wind, it has kinetic energy. The kinetic energy of wind can be captured by a wind turbine and converted to other forms of energy such as electricity or mechanical power.