Wind turbines are the essential element of wind energy. It is a renewable and environmentally friendly source of energy.
A wind turbine consists of the following parts:
Wind Turbine Base
A wind turbine must be well anchored to the ground on which it is located. Sometimes a shallow foundation is used for cost reasons. The base is made of concrete and is equipped with penetrations through which electrical wiring can pass.
In offshore wind farms there are three common types of foundation: a three-legged foot, a scoop base, a straight mast. However, the possibility of making floating windmills without direct anchoring to the seabed is being investigated.
Wind Generator Mast
The mast of a windmill must be able to withstand many loads. In addition to supporting the weight of the gondola and the electric generator, it has to be resistant to the load of the wind. Inside the mast is a ladder, possibly an elevator, and power cables.
The wind turbines currently installed are an average of 100 meters high. However, wind turbines with higher heights have already been built . Wind speed increases with height, so that at higher altitudes you get a better performance.
The Gondola and the Electric Generator
The nacelle is the cabin on top of a wind turbine. Inside there is the electric generator and in some cases a gearbox. The electric generator converts the mechanical energy of the shaft into electricity according to the principle of Faraday's law. The gearbox serves to increase the rotation speed of the shaft at the input of the generator.
Wind turbines are equipped with an aerodynamic braking system to be able to stop them during emergency or maintenance situations. In the gondolas a wind meter is installed to activate or deactivate the rotation of the blades depending on the wind speed.
Wind turbines also have an orientation system to face the blades to the direction of the wind.
Blades of a Wind Turbine
The blades of a wind turbine are aerodynamically designed to convert the kinetic energy of the wind into mechanical energy that is transmitted to the rotor shaft.
Modern blades are made of fiberglass or carbon fiber reinforced plastic. The maximum length of modern wind turbine blades is about 65 meters for onshore turbines and about 85 meters for offshore turbines. The longer the blade, the higher the speed at the end of the blade.
The blades rotate at a constant speed of between 15 and 40 revolutions per minute. However, some wind turbines operate at a variable speed. The revolutions of rotation depend on a physical limit that is the maximum speed of the tip of the blades.