Application Note: Wind Turbines Today
In today's ongoing search for sources of alternative energy, clean, green, and renewable are top priorities. Using wind power to produce electricity is a perfect fit.
Wind is air set in motion naturally. According to Evangelista Torricelli, who first gave the correct scientific explanation in the mid 1600s, "…winds are produced by differences of air temperature, and hence density, between two regions of the earth." The sun heats the earth unevenly because of differences in earth surfaces. The earth’s rotation is also a key factor in wind production.
Wind power is the conversion of wind energy into electricity. This is achieved using wind turbines, which convert the kinetic energy of wind into electrical energy as follows:
- Wind turns propeller-like blades around a rotor.
- The rotor, which is made up of the blades and hub, causes a low-speed shaft to turn at approximately 30-60 rotations per minute (rpm).
- The low-speed shaft connects to a 2- or 3-stage speed-increasing gearbox that connects it to a high-speed shaft and increases the rpm to approximately 1000-1800 rpm. This is the rotational speed most generators require to produce electricity.
- The high-speed shaft drives a generator.
- The generator produces electricity.
The process of converting wind power to electricity is clean, environmentally sound and, as long as the sun keeps shining and winds are created, completely renewable.