Wind turbines are used to convert the wind’s kinetic energy to electricity. Wind energy proposals may be for single turbines or for groupings of turbines (wind energy development). Planning authorities should be aware that wind turbine technology is continually changing.
A wind-turbine will generally include the following elements:
A) Tower: Currently may vary in height from 35 metres upwards. Tubular steel towers typically have a base diameter of 3-7 metres and display a slight tapering to the nacelle. Larger towers may require a larger base diameter.
B) Nacelle: This contains the key mechanical components of the wind turbine including the gearbox and generator. A yaw mechanism is employed to turn the nacelle so that the rotor blades face the prevailing wind.
C) Blades: The blades, which capture and are set in motion by the wind, are most commonly made of glass reinforced plastic or wood epoxy but can be made of aluminium or steel. Modern turbines typically have three blades. These may vary in rotor diameter from 35 metres upwards.
D) Transformer: This is a device for changing the voltage of the alternating current. Electricity is typically generated at less than 1000 volts by the wind turbine and the transformer “steps up” this voltage to match that of the national grid. This may be housed either inside or alongside the tower.
Concrete foundation bases: Turbines typically have bases of between 7 and 18 metres square and a hardstanding area at the base of each turbine.