An image of a Wind farm and the following text is written below the image: Wind farm: Enormous wind farms like this one in California can generate as much power as a large power plant (without any air pollution). The parts and functions of a wind turbine: Wind direction Direction of rotation Rotor shaft Blades: The shape and angle of the blades are designed to extract as much energy as possible from the horizontal movement of the wind. Gearbox: The rotor shaft itself rotates fairly slowly at about 20–30 revolutions per minute. The gearbox converts this to a rotation some 50 times faster—about 1500 revolutions per minute. Generator: The shaft from the gearbox enters the generator, which converts the kinetic energy of the shaft into electrical energy. Electrical energy passes to the local grid. The anemometer measures wind speed. Wind vane Control unit: This computer-operated unit controls the yaw drive mechanism, ensuring that the turbine always faces directly into the wind. Yaw drive mechanism Electrical energy passes to the local grid A yaw ring changes the direction of the turbine.