A wind turbine is a device that converts the kinetic energy of wind into electrical energy. As of 2020, hundreds of thousands of large turbines, in installations known as wind farms, were generating over 650 gigawatts of power, with 60 GW added each year.
source.image: The Engineering Mindset
To capture wind energy, the top part of the turbine is turned to face the wind, the three blades are set at exactly the right angle, and the movement of the air past them causes them to rotate.They spin around the central axis and create mechanical energy from the movement of air.The turbine blades spin a rotor inside the central shaft of the turbine.
Machinery inside the turbine next to the rotor converts the mechanical energy into electrical energyWithin the nacelle the non-rotating part on top of the turbine the blades’ rotation is passed through a drive shaft, often via gear box, to turn magnets inside a coil of wire. This generates an alternating current of electricity.Turbines used in wind farms for commercial production of electric power are usually three-bladed. These have low torque ripple, which contributes to good reliability.
The blades are usually colored white for daytime visibility by aircraft and range in length from 20 to 80 meters. The size and height of turbines increase year by year. Offshore wind turbines are built up to 8 MW today and have a blade length up to 80 meters (260 ft). Designs with 10 to 12 MW were in preparation in 2018,and a “15 MW+” prototype with three 118 meters (387 ft) blades is planned to be constructed in 2022.