Below is the text version for the Energy 101: Wind Turbines - 2014 Update video.
The words “Energy 101: Wind Turbines - 2014 Update” appear onscreen, followed by footage of an old windmill.
We’ve all seen those creaky, old windmills on farms.
Montage of windmill on a farm.
And although they may seem about as low-tech as you can get, those old windmills are the predecessors for new, modern wind turbines that generate electricity.
Montage of wind turbines and wind farms.
The same wind that used to pump water for cattle is now turning giant wind turbines to power cities and homes.
OK, have a look at this wind farm in the California desert. A hot desert… next to tall mountains… an ideal place for a lot of wind. Here’s another one on the windy prairies of Wyoming.
Now today’s wind turbines are much more complicated machines than the old prairie windmills… but the principle is the same…both capture the wind’s energy.
3D animation of a wind turbine spinning.
OK… Here’s how it works.
3D animation of a wind turbine spinning, with airwaves passing on either side.
First, a wind turbine blade works sorta like an airplane wing. Blowing air passes around both sides of the blade. The shape of the blade causes the air pressure to be uneven – higher on one side of the blade and lower on the other. And that’s what makes it spin… the uneven pressure causes the blades to spin around the center of the turbine.
3D animation of a weathervane spinning on top of a wind turbine.
On the top, there’s a weather vane that’s connected to a computer… to keep the turbine turned into the wind so it captures the most energy.
3D animation showing the inside of a wind turbine spinning. The words "Rotor Spins – 18 RPM" appear onscreen.
Now the blades are attached to a rotor which only turns about 18 revolutions a minute…and that’s not nearly fast enough to generate electricity by itself.
3D animation showing gears spinning inside of a wind turbine spinning. The words "Generator – 1800 RPM" appear onscreen.
So, the rotor shaft spins a series of gears that increase the rotation up to about 1800 revolutions per minute. And at that speed, the generator can begin to produce electricity.
Montage of wind turbines spinning.
So why are wind turbines so tall? Well… the higher up you go… the windier it is. More wind naturally means more electricity.
3D animation of a wind turbine spinning.
Larger turbines can also capture wind energy more efficiently.
3D animation of a wind turbine spinning. The words "Turbine Blades = More than 150 feet" appear onscreen.
The blades can sweep a circle in the sky, with a diameter longer than a football field.
Footage of wind turbines spinning.
Now what’s really cool is that even a small wind farm like this one in Wyoming…
Footage of a vehicle driving down the road, with a wind farm in the background.
…can generate enough electricity to power more than 9,000 homes... and larger farms can provide much more clean energy for our homes and businesses.
Montage of offshore wind turbines. The words "Offshore Wind Farms" appear onscreen.
And it’s not just on land that turbines can capture the wind.
Our oceans and the Great Lakes provide a reliable and consistent source of wind that we can capture and turn into electricity.
The Energy Department is supporting innovative offshore wind projects that will help build some of the first offshore wind turbines in U.S. waters.
Montage of offshore wind turbines.
As the wind energy industry continues to grow, offshore development has the potential to significantly boost domestic renewable energy production, especially in coastal areas.
Montage of nighttime traffic driving over a bridge, an offshore wind farm, and a city highway/skyline.
With more than 50% of the U.S. population living within 50 miles of a coastline, capturing wind off America’s shores has the potential to provide energy to countless homes and businesses.
Montage of onshore and offshore wind farms.
Wind energy… on land or offshore…a reliable and renewable clean energy source, helping move America toward energy independence.
Caption: Energy 101: Wind Turbines - 2014 Update. For more information, visit eere.energy.gov.