The functioning of a wind turbine is simple and is based on the functioning of a wind mill.
Energy produced by a wind turbine depends on many different parameters: the length of the blades, the speed of the wind as well as the air density.
The machine is composed of 3 blades (in general) carried by a rotor and installed at the top of a vertical mast.
This is fixed to a nacelle that houses a generator. An electric motor controls the orientation of the nacelle and blades so that they always face the wind. The blades allow the transformation of the kinetic energy (energy of movement) of the wind into mechanical energy.The wind turns the blades between 10 and 25 rotations per minute. The speed of the rotation depends on their size. The bigger the blades, the less rapidly that they turn.
The generator transforms mechanical energy into electrical energy. The majority of the generators need to turn at a high speed (from 1000 to 2000 rotations per minute) to produce electricity. In addition, the gear box acts to accelerate the slow movement of the blades.
Electricity produced by generator has a tension of approximately 690 volts. Not capable of being used directly, it is transformed by a gear box and its tension is increased to 20 000 volts. It is then injected in the electrical network and can be distributed to consumers.
The wind turbines function for wind speeds between 14 and 90 km/h. Beyond that they stop for security reasons. Electricity production varies according to the speed of the wind. At wind speeds of 45 to 90 km/h wind turbines produce their maximum output.