In the world of green energy, there are two main contenders — solar energy and wind energy. Wind farms have been popping up around the world, acres of multistory-high windmills that can convert a passing breeze into electrical power for the local grid. How are these wind turbines made, and how do they generate electricity?
While the exact makeup of an individual wind turbine may vary depending on its or the local wind speeds, most turbines will be made up of three similar pieces — a tower, a nacelle, and a set of rotor blades.
The towers can range in height from 212 feet to 262 feet, depending on the manufacturer. This height doesn’t include the sweeping rotor blades, which can add an additional 116 to 148 feet of height to the tower once installed. Most towers are made of reinforced steel that has been coated with zinc or painted to protect it from the elements. The metal for the towers is formed, cut, and even etched using abrasive materials. The blasting materials used will depend on the base material of the tower.
The nacelle rests on the top of the tower and holds all of the moving parts that power the turbine. The nacelle itself is most often made of fiberglass, and holds the drive shaft that supports the rotor blades, as well as a hydraulic system that helps to control the position of the blades. A fully equipped nacelle will usually weigh upwards of 22,000 pounds.
To catch the wind, the tower is equipped with a set of rotor blades. Most are hollow and made of fiberglass, but they can also be made of anything from aluminum to plastic and even balsa wood.
Somewhere on the tower, there will also be a utility box, which is where the magic happens — or, the science if we’re being realistic here. The utility box will be connected to the nacelle and it will convert the spinning of the rotor blades into electricity.
Turbines are designed to turn the spinning of the rotor blades into electricity, but how does that work? First, the wind has to be converted to mechanical energy. That’s what happens when the rotor blades spin. The drive shaft in the nacelle, connected to the utility box, spins and helps to create and capture mechanical energy.
This mechanical energy is routed to a generator. Inside the generator is a rotor that is covered with oppositely charged magnets. The rotor itself is wrapped in loops of copper wire. Spinning the rotor inside the copper wires generates electricity by means of electromagnetic induction.
Once the electricity has been generated, it needs to have its voltage increased to make it usable on the grid and so it can be transferred across the distances between the wind farms and the homes that use the electricity.
Once it reaches your neighborhood, your local power stations lower the voltage again so it can be safely used in your home.
New turbine designs
Not everyone likes the idea of an enormous wind turbine on their property — even if they’re generating green energy, they’re an eyesore and they can be dangerous to birds and other wildlife. This necessity has helped engineers and innovators create new ways to take advantage of wind power without relying on enormous rotor blades.
The ideas that have emerged thus far are promising — everything from helium filled turbines that float at 1000 feet above the ground to bladeless Vortex turbines that harvest energy from swirling wind vortices in the air. All of these new designs have one thing in common — they don’t rely on blades to capture the power of the wind.
Green energy is going to become even more important as we start exhausting the planet’s supply of fossil fuels. We can potentially power the globe with wind and solar energy —and this will also help to reduce our global carbon footprint and slow down the effects of global warming.
This article was written by Megan Ray Nichols. If you enjoyed this article, please visit her page Schooled by Science.