The green revolution is powered by many different technologies, but wind turbines may be the one of the most important. Even with its growing prevalence, many wonder how does a wind turbine work? Let’s take a look.
The Generator
Generators are how most electricity is generated, and wind power is no exception. Fairly simple, generators consist of a coil of wire surrounding a permanent magnet. Through something known as electromagnetic induction, spinning the permanent magnet will induce the electrons in the coil. The moving electrons are what we call electricity.
If that sounds familiar, it’s because it is essentially an electric motor in reverse. If you were to apply a current to the coil, you would create an electromagnet that would spin the permanent magnet around. You may have even built one in elementary school. [1]
The Blades
In addition to the generator, in order to understand how a wind turbine works we have to look at the blades. The iconic fins of a wind turbine provide rotational energy to the generator. Much like the blades on an aircraft’s propeller are shaped so that the slightest spin will move a large volume of air, a wind turbine’s blades are designed to spin with a constant breeze. The shape is optimized for constant wind, so the air currents in the Midwest are perfect for large-scale wind farms. Their shape requires that they point into the wind, which means that the entire contraption is usually mounted on a giant pivot. [2]
There is also a number of vertical wind turbine designs, such as the Savonius [3]. These have the advantage of a narrow, fixed footprint and a simpler design, thanks to fewer moving parts. However, they also have a tendency to stall in gusts, making them impractical in many situations. In addition, they tend to have less energy output than their fan-shaped cousins.
An interesting variation on the traditional blade design has recently become popular among wind power hobbyists and proponents of private wind turbines. [4] Consisting of blades wrapped like the DNA double helix, these blades manage to handle gusting wind quite well. In fact, they actually thrive in an environment of gusty air. Their energy output isn’t near what a traditional fan-shaped design could produce, but their smaller footprint, simpler design, ability to handle gusty conditions, and relative quietness make them ideal for city use. In fact, many entrepreneurs are trying to take advantage of the wind tunnel effect many cities suffer from by installing these on city roofs.
The Whole Device
So how does a wind turbine work?
Put simply, some form of blade harnesses the wind to spin a turbine, which generates electricity. It’s really as simple as that. Of course, the design gets more complicated if you actually want to generate useful power. If you are using traditional high-efficiency propeller blades, you are going to need to mount the entire contraption on a pivot, so that the blades are always pointing in the wind. You also have to build the turbine in a place with consistent wind, because that type of turbine doesn’t like bursts. Vertical turbines are simpler and can handle sparser wind, but they don’t produce as much power and can stall if the wind bursts too much.
A growing number of wind turbines is being built on the water, to take advantage of the fast ocean winds. Many coastlines have the perfect conditions for power generation, but building a turbine on the water is quite difficult.
Sources:
1. http://www.generatorguide.net/howgeneratorworks.html
2. http://www.google.com/url?sa=t&source=web&cd=1&ved=0cboqfjaa&url=http%3a%2f%2fdearscience.org%2f2008%2f07%2f23%2fwind-power%2f&ei=sfdgtdute8nx0ggrtjw3bw&usg=afqjcnffxumcivgumhqlsqva2k19cg_prg
3. http://en.wikipedia.org/wiki/savonius_wind_turbine
4. http://inhabitat.com/eddy-gt-wind-turbine-is-sleek-silent-and-designed-for-the-city/
