Wind power is the conversion of the energy in wind into a more useful form of energy, like electricity.[2] It is a renewable source of energy that helps to cut down on the pollution of earth's air.
Wind power capacity has expanded quickly to 336 GW in June 2014, and wind energy production was about 4% of total worldwide electricity usage, and growing fast.[3] Wind power is widely used in European countries, and more recently in the United States and Asia.[4][5] In 2012, wind power accounted for approximately 30% of electricity generation in Denmark, 20% in Portugal and 18% in Spain.[6]