What is a variable pitch wind turbine?
A variable pitch turbine is one in which the rotor blade pitch angle is continuously adjusted by an internal hub mechanism to provide constant speed output over a wide range of wind speeds. It is a precision solution to overspeed control. Variable pitch wind turbines start very efficiently in low speed winds, such as those typically found around more populated areas. Upon starting to move, the rotor blades adjust in pitch, enabling the turbine to reach operating speed quicker than fixed pitch blades. Upon reaching the controlled operating speed they continue to adjust and produce power at constant output speed, right up to and including very high wind speeds, regardless of wind speed or electrical load. There is no need to avoid operating in high winds. And, significantly, because constant operating speed is readily reached at lower speed winds, the need for high and costly towers is much reduced.
