<P> For a given survivable wind speed, the mass of a turbine is approximately proportional to the cube of its blade - length . Wind power intercepted by the turbine is proportional to the square of its blade - length . The maximum blade - length of a turbine is limited by both the strength and stiffness of its material . </P> <P> Labor and maintenance costs increase only gradually with increasing turbine size, so to minimize costs, wind farm turbines are basically limited by the strength of materials, and siting requirements . </P> <P> Typical modern wind turbines have diameters of 40 to 90 metres (130 to 300 ft) and are rated between 500 kW and 2 MW . As of 2014 the most powerful turbine, the Vestas V - 164, is rated at 8 MW and has a rotor diameter of 164m . </P> <P> The nacelle is housing the gearbox and generator connecting the tower and rotor . Sensors detect the wind speed and direction, and motors turn the nacelle into the wind to maximize output . </P>

What is the size of a wind turbine