Most wind turbines start operating at a speed of 3-5 metres per second and reach maximum power at about 25 metres per second.
The diagram below shows how a wind turbine converts the kinetic energy in the wind to electrical energy. You may need to download Flash to view it.
The wind turns the blades (most turbines start operating at 3-5 metres per second and reach maximum power at about 25 metres per second).
The blades turns a shaft inside the nacelle (the box at the top of the turbine).
The shaft goes into a gearbox which increases the rotation speed.
The generator converts the rotational energy into electrical energy.
The transformer converts the electricity from around 700 Volts (V) to the right voltage for distribution, typically 33,000 V.
The National Grid transmits the power around the country.
A typical wind turbine consists of the following components:
Towers - mostly cylindrical, made of steel, painted light grey, and from 25 to 75 metres in height.
Rotor Blades - from one to three blades, made of fibre-glass-reinforced polyester or wood-epoxy. The blades are usually between 30-80 metres in diameter. The longer the blades, the greater the energy output. They rotate at 10-30 revolutions per minute at constant speed, although an increasing number of machines operate at a variable speed. The blades can be rotated to change the pitch angle and modify power output.
Yaw mechanism - turns the turbine to face the wind.
Wind Speed & Direction Monitor - sensors monitor wind direction and the tower head is turned to line up with the wind. Power is controlled automatically as wind speed varies and machines are stopped at very high wind speeds to protect them from damage.
The Gear Box - most turbines have gearboxes, although there are increasing numbers with direct drives.