Wind turbines convert the kinetic energy of wind into electricity. A wind turbine consists of:
- Rotor (blades)
- Gondola (gearbox, hub, generator and wheelbarrow)
- Mast, containing cables
The gondola contains the basic parts of a windmill: The drive shaft and the generator. The wind turbine generator is the part where the wind energy is converted into electricity. In the generator the mechanical energy is converted into electrical energy and works as a kind of large dynamo. By the movement of the shaft in a magnetic field current voltages are generated. The current goes through the high voltage cables in the mast to the transformer, which brings the current to the correct voltage level and puts it on the electricity network. The transformer is located in the gondola or on the ground next to the windmill.
The blades called rotor blades are always facing the wind. Modern windmills can change the position of the rotor blades so that they can always be in optimal position. The rotor blades are made of epoxy resin and glass fiber and have the shape of airplane wings, they are driven by lift force caused by the wind.
The shaft height and the rotor diameter determine the actual output. The higher the mast, the more wind the rotor blades catch, so the higher the power output. How much power a wind turbine ultimately produces also depends on the wind supply at a location and whether there are trees or buildings nearby. Wind turbines can convert the wind into energy at wind force 2-3, but the best is wind force 6 (approx. 10-11 m/s).