Tower height varies according to wind turbine models, but generally range from 6 to 12 meters for stand-alone machines, which are often used to provide a power source where grid power is not available. In general, the higher the tower, the higher the average wind speed that the turbine will experience and the smoother the wind. The rotor diameter of small wind turbines ranges from 1.0 to 11 meters depending on the type of a model.