Rotor

Turning the blade of a rotor into the wind, the air flow is deflected at the front rotor tip. The way along the curved upper side is longer than along the relatively straight underside. Due to physical reasons, low pressure is created on the upper side and positive pressure on the underside. In order to balance this difference, air presses the blade up. This is how rotors of wind turbines move.

Modern wind energy converters usually have three rotor blades made out of glass or carbon fiber reinforced plastics and a pitch control mechanism. Pitch control reacts to an electronical signal: if the wind blows heavily, it turns the rotor blades away from the wind - in the event of a storm, blades are turned until the rotor comes to a stop.