Welcome to the wind rodeo, my friends. We’re going to lasso a few pockets of air in motion. Then we’re going to tame that wind and make it do our bidding.
This is hardly a new idea. We’ve been harnessing the power of wind ever since we figured out a sail attached to a vessel could cause it to putter across water. According to the US Department of Energy, by “200 B.C., simple windmills in China were pumping water, while vertical-axis windmills with woven reed sails were grinding grain in Persia and the Middle East.”
Now think of windmills in a field of tulips. These massive structures once used the power of the wind to act upon machinery that drained lakes and marshes in order to do battle with frequent flooding from below-sea-level areas in the Netherlands. It’s just one of the many agriculture and industrial uses of the humble windmill throughout the ages.
Today wind turbines use the same premise – capturing the kinetic energy of fast-moving particles in air and converting that energy into electricity. Wind farms, collections of wind turbines, are spread across the globe, and wind energy is the world’s fastest-growing energy source.
So let’s put a saddle on the wind and ride it, shall we?
When wind meets the blades of a wind turbine, it causes the blades to capture the wind (like the sail of ship) and convert it into energy (like a ship moving forward as the wind pools and pushes the sails, acting on the ship. Though in this case we’re talking about rotational energy since the blades of the wind turbine are rotating in a circle.)
At the same time that the blades are moving a shaft in the wind turbine also moves, transferring the rotational energy into the nacelle, an area of the turbine that acts as the guts of turbine. You could also think of it as the “man behind the curtain” as you stare at the great Oz of the wind turbine.
The nacelle holds the components of the structure that help capture and convert energy. These components include the gearbox, generator, electrical control box, yaw controller (it aligns rotor with direction of wind) and brakes.
Within the generator electromagnetism creates electricity from the wind’s particles, resulting in medium voltage, or thousands of volts. From here it travels down electric cables housed within the tower of the wind turbine, where it meets with a transformer located at the base of the structure. The transformer increases the voltage of the electric power to distribution voltage, thousands of volts.
This power is then shuttled through underground lines where it could be combined with energy from other wind turbines. Or it could be sent on to farms, factories and homes. Or it could take yet another journey, this time to a substation where it would get an upgrade in its energy level and earn itself a ticket on above-ground transmission lines into the big city.
Just another day for a few air molecules floating through the terrarium we call Earth.
About the author: Julie Douglas is a podcaster, writer and editor at HowStuffWorks and a sometimes phlebotomist and pyrotechnician, not to mention a fabulist of bios and the co-host of the Stuff to Blow Your Mind podcast.