Turbine blades: For the turbine blades to rotate, the face of the turbine must point into the wind. Because each blade of the wind turbine is angled in a special way - like an aeroplane's wing - a force known as a 'lift' is generated on one side, and the blades start to spin round. A sensor above the nacelle constantly monitors the wind direction and speed to make sure the turbine keeps pointing into the face of the wind.
Gearbox: To generate electricity, the shaft in the generator needs to turn very fast; well over 1,000 revolutions per minute. But this is too fast for the huge blades of a wind turbine. So a gearbox is used, enabling the shaft going into the front of the gearbox to rotate at low speed, with the shaft coming out of the back able to turn many times faster.
Anemometer: An 'anemometer' calculates how fast the wind is going, so that the turbine can brake if it's turning too fast. There are two braking systems on the turbine: one is on the blade tips, and the other is a disc brake connected to the high-speed shaft within the nacelle.
Nacelle: When the wind direction alters, the nacelle is rotated by hydraulic motors so that the rotor blades face into the wind to maximise the energy captured.
Cable to substation: The electrical energy is transmitted along cables to a substation. Here it's converted to a high voltage, before being delivered to homes and businesses.
Electricity generator: The shaft coming out of the gearbox is connected to a generator. This uses an electromagnetic field to convert the mechanical energy into electrical energy. The generator produces power at 690v, which is transformed to a higher voltage usually 20kV or above.