The wind turns the blades, which spin a shaft, which connects to a generator and makes electricity. Utility-scale turbines range in size from 50 to 750 kilowatts. Single small turbines, below 50 kilowatts, are used for homes, telecommunications dishes, or water pumping. Wind turbine photos. Measures the wind speed and transmits wind speed data to the controller.
Most turbines have either two or three blades.
A disc brake which can be applied mechanically, electrically, or hydraulically to stop the rotor in emergencies. Turbines cannot operate at wind speeds above about 65 mph because their generators could overheat. A cover protects the components inside the nacelle. Some nacelles are large enough for a technician to stand inside while working. Blades are turned, or pitched, out of the wind to keep the rotor from turning in winds that are too high or too low to produce electricity.