Wind turbine

A wind turbine is a device that converts the wind's kinetic energy into electrical energy. Wind turbines are manufactured in a wide range of vertical and horizontal axis. The wind's movement rotates the turbine's blades, which captures the kinetic energy of the wind and converts this energy into a rotary motion via a shaft to drive a generator and make electricity. Large three-bladed horizontal-axis wind turbines (HAWT) with the blades upwind of the tower produce the overwhelming majority of wind power in the world today. These turbines have the main rotor shaft and electrical generator at the top of a tower, and must be pointed into the wind. Small turbines are pointed by a simple wind vane, while large turbines generally use a wind sensor coupled with a yaw system. Most have a gearbox, which turns the slow rotation of the blades into a quicker rotation that is more suitable to drive an electrical generator. Some turbines use a different type of generator suited to slower rotational speed input. These don't need a gearbox and are called direct-drive, meaning they couple the rotor directly to the generator with no gearbox in between.