Introduction
We have been harnessing the wind's power for hundreds of years, since the first windmills were used to pump water and grind grain. Today, wind turbines generate electricity cheaply with no harmful waste and form the basis of the fastest growing source of electricity in the world.
What is wind turbine?
A wind turbine is a structure that uses the wind to make electricity. There are two types:
Horizontal-axis turbines: The axis of rotation is parallel to the ground.
Vertical-axis turbines: the axis of rotation is perpendicular with the ground.
How a Wind Turbine Works
A wind turbine consists of several components including:
Controller: starts the turbine at acceptable speeds and stops the turbine at high wind speeds to prevent overheating.
Gearbox: makes the shaft turn fast enough to drive the generator.
Generator: converts the motion of the spinning shaft into electricity.
Rotor: the name given for the blades and the hub.
Tower: enables turbines to increase generated electricity by taking advantage of higher wind speeds at greater heights.
Yaw drive: keeps the rotor facing into the wind
Yaw motor: powers the yaw drive
Efficiency Factors
Several factors affect the amount of electric power a wind turbine may produce:
Wind direction: to achieve maximum efficiency, wind turbines need to adapt to the changing wind direction to take advantage of the most active winds. This is accomplished through mechanical or computer controls.
Wind shear: wind shear is the increase of wind speeds at higher altitudes. The electrical output of a wind turbine can thus be increased by installing it on a taller tower.
Obstacles and surrounding terrain: obstructions will slow down wind and may cause turbulence.
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Summary
As the cost of wind power becomes cheaper and more emphasis is placed on the protection of the environment, electricity generated by the wind is sure to continue and increase in the future.