How Contemporary Wind Turbines Work
Most commercial-scale wind turbines have three basic components: the tower, the rotor, and the nacelle.
The towers, typically 60 to 90 metres high, are often made from three or four slightly tapered hollow steel tubes that are hoisted into place by a crane and then bolted together. The steel is a few centimetres in thickness and the tubes may be several metres in diameter. They are erected on a cement foundation. Some towers can also be made of concrete. Inside the tower is a ladder or elevator leading up to the nacelle. There is a service entrance at the base, as well as computerized control consoles.
Conventional horizontal turbines have three blades, which measure 40 metres or longer for the largest offshore models. Fabricated from reinforced fibre glass, they are tapered like airplane wings and attached to the nose on pivoting axes. The newest turbine blades have textured surfaces to reduce noise and drag.
The nacelle is a bus-sized housing perched at the top of the tower which contains the electronic and mechanical components that run the turbine; in a state-of-the-art turbine, the nacelle may have as many as 10,000 parts. The rotor is attached to a high-tech gear box that accelerates the rotation of the central shaft, which drives a generator and produces an electric current. Turbines that operate at lower rotational speeds do not require a gearbox; instead, the rotor is affixed directly to the generator.
On the exterior of the nacelle are instruments that detect wind speed and direction. The information is continuously fed into the turbine’s central system, which automatically adjusts the turbine direction and the pitch of the blades to maximize their generating potential.
Wind turbines are sited in locations with strong, consistent winds. In very powerful winds, the nacelle will automatically swivel the blades to a right angle to the wind to prevent damage.
This interactive show contains two selectable views of a modern wind turbine: one a picture showing the entire turbine, the other a graphic focused on the nacelle portion with a cutaway revealing the working parts. Each view has labels that appear when rolled over giving names of the various structural components, with descriptive text appearing beneath.