At present wind energy is being widely used to generate electricity. The devise which is used to convert wind energy directly to electrical energy is called as wind turbine. Many people get confused between the terms windmill and wind turbine and many people call wind turbine as a windmill. The wind turbine comprises of large turbines looking like the fans. The blades of this fan are attached to hub, which is mounted on a shaft. When the wind blows, it rotates the fan blades, which in turn rotates the shaft of the wind turbine.
The shaft is connected to a gear box. Inside the gearbox the shaft rotates large gear at slow speed, and by various transmissions the output is obtained on a small gear at high speeds. Thus the gearbox output shaft rotates at the fast speed. This shaft is connected to the generator which produces electricity. If the speed of the blowing wind becomes faster, there are brakes to control the fan speed.
The place where large numbers of wind turbines are installed is called as wind farm or wind power plant. In the wind farms large amounts of electricity is generated and they can be connected to the national grid. At present the wind turbines are being used to produce electricity on commercial basis as well for domestic purposes.