Image credit: Lepti
Whether a wind turbine is a horizontal axis or vertical axis turbine, it will have four main components: a foundation, tower, nacelle and rotor. Some components, like the foundation are relatively simple, while others, like the nacelle contain high tech instruments, but they are all critical to ensure that the system operates safely and at peak efficiency.
Foundation
In most cases, wind turbines are mounted to a concrete foundation on the ground. Other types of installations can include off-shore turbines which are connected to concrete foundations embedded in the ocean floor and smaller turbines which can be attached to rooftops.Tower
The purpose of the tower is simple - to raise the nacelle and blades above the ground to a height where the wind speed is greater. Typical wind turbines are 150-300 feet above the ground.Nacelle
The nacelle, also referred to as the turbine housing, sits at the top of the tower and contains the majority of a wind turbine's components.- Low speed shaft - Transfers the rotational energy from the rotor to the gearbox.
- High speed shaft - Drives the electrical generator.
- Brake - Prevents the blades from rotating for performing repairs or to prevent damage from high winds (typically 50 mph or greater).
- Gearbox - By reducing the torque, the gearbox increases the rotation speed of the low speed shaft (from the blades) to the high speed shaft (of the generator).
- Generator - Converts the mechanical/rotational energy into electrical energy.
- Transformer - Converts the electricity from the generator to the correct voltage needed for the power grid.
- Electrical control system
- Anemometer - Measures wind speed, which is critical to determining when to engage the brake to shutdown the turbine during heavy winds which could damage the turbine.
- Wind Vane - For small wind turbines, the wind vane aligns the turbine in the direction of the wind. Large turbines generally use a computerized wind sensor with a yaw motor to control the direction of the turbine.
