This type of turbine is referred to as a 'horizontal axis' machine. Rotor diameters range up to 65 metres. Turbines are stopped at very high wind speeds to protect them from damage. The yaw mechanism turns the turbine so that it faces the wind. Sensors are used to monitor wind direction and the tower head is turned to line up with the wind.
Towers are mostly tubular and made of steel, generally painted light grey.
Lattice towers are used in some locations. Towers range from 25 to 80 meters in height. Turbines can range in capacity from several kilowatts to several Megawatts. The crucial parameter is the diameter of the turbine - the longer the blades, the larger the areas swept by the rotor and the greater the energy output. At present the average size of new machines being installed is 600 kilowatts, although there are 1.5 Megawatt machines on the market.