Wind Energy old onto your hat! Roscoe, , is also known as H Wind City, U.S.A. The town is home to one of the country’s largest wind farms. You won’t see corn or cotton growing on this farm. Instead, you’ll find over 600A Gusttall structures of calledPower wind turbines. Wind turbines have blades attached to a generator, a machine that turns motion into energy. As wind makes the blades spin, the generator produces electricity. is available almost everywhere. People have used it as a natural source of energy for centuries. Before electricity, many people used windmills to capture wind energy. Windmills can be attached to large stones to grind grain into flour. Or they can be attached to saws to cut wood.

enewable Energy Energy R enewable The Roscoe can make enough electricity to e s Re sourc En e rgy power over 250,000 homes using this renewable energy source. It makes as much electricity in a year as burning 80,000 tons of coal would. Unlike fossil fuels, such as oil and coal, wind power doesn’t add greenhouse gases to UNITED STATES the atmosphere. And wind will never run out. You could say the energy appears “out of thin air”! TEXAS Wowser! Roscoe About four percent of all the electricity in the United States comes from wind. That may not sound like a lot, but it’s enough electricity to power ten million homes each year. File Roscoe Wind Farm

© Learning A–Z All rights reserved. Credits: © DreamPictures/Shannon Faulk/Superstock www.sciencea-z.com Investigation File 1 Three-Winged Wonders Wind turbines look like huge fans. Fans use electricity Ocean Breezes to make wind, but wind turbines use wind to make nose cone Wind farms are built in places with strong electricity. and predictable winds. For this reason, many A usually has three blades, which are generator wind farms are built right in the ocean (see shaped like the wings of an airplane. Each blade is below). The winds over water can be very tilted at an angle to catch the wind. When a steady fast—over 145 kilometers per hour (90 mph). wind pushes on the blades, it causes them to spin. As On average, they are faster than winds over the blades turn, the generator produces electricity. land. Ocean winds also blow about 40% more The electricity moves through power lines to people often than winds over land do. This means that who need it. It can also be stored in batteries to be wind turbines in the ocean can spin faster and used when the wind slows down. more often than those on land. This results in more electricity. tower

blade T hink About It Why are wind turbines placed on tall towers instead of being close to the ground? A wind farm in the ocean Math Moment Suppose a wind An average wind turbine is turbine makes 10 full turns in 110 meters (360 ft.) tall. one minute. How many times That’s about 80 times taller than you! will it turn in one day?

Credits: center: © Pedro Antonio Salaverría Calahorra/Dreamstime.com; © Learning A–Z All rights reserved. Investigation File right: © iStockphoto.com/Lance Bellers; www.sciencea-z.com Energy Resources } Renewable Energy } Wind Energy background: © DreamPictures/Shannon Faulk/Superstock 2