The electrical generator is usually a so-called induction generator or asynchronous generator. The electronic controller contains a computer which continuously monitors the condition of the wind turbine and controls the yaw mechanism. The hydraulics system is used to reset the aerodynamic brakes of the wind turbine. The cooling unit contains an electric fan which is used to cool the electrical generator. In addition, it contains an oil cooling unit which is used to cool the oil in the gearbox.
Some turbines have water-cooled generators.
The tower of the wind turbine carries the nacelle and the rotor. Generally, it is an advantage to have a high tower, since wind speeds increase farther away from the ground. Tubular towers are safer for the personnel that have to maintain the turbines, as they may use an inside ladder to get to the top of the turbine. The advantage of lattice towers is primarily that they are cheaper. The yaw mechanism uses electrical motors to turn the nacelle with the rotor against the wind.