Wind turbines consist of four main components—the rotor, transmission system, generator, and yaw and control systems Rotor: The rotor consists of the hub, three blades and a pitch regulation system, all of which are located upwind of the tower. The blades are airfoils, which depend on aerodynamic lift to move the blades and cause rotation. (Air moving over the blades creates a negative pressure on the upper side of the airfoil and a positive pressure on the lower side; this causes the rotor to rotate.) The design speed of the rotor is 16 rpm. Transmission system: The mechanical power generated by the rotor blades is transmitted to the generator by the transmission system. This consists of a gearbox and a braking system plus the auxiliary lubricating and cooling systems. The gearbox is needed to increase the rotor’s speed (16 rpm) to the 1800-rpm speed of the generator. The braking system is designed to lock the rotor when shut down. Generator: The generator converts the mechanical energy to electrical energy in an asynchronous (induction) generator. Yaw and control systems: The yaw system turns the nacelle into the actual wind direction using a rotary actuator and a gear mechanism at the top of the tower. A fully automatic microprocessor-based control and monitoring system is a part of the wind turbine. The control system is designed for remote operation from the shore-based operations center via a fiber optic communications system.