WY Field Trip - Wind Farm - Facts

Wind energy is the fastest growing source of electricity in the world, according to the U.S. Department of Energy. Let's learn about wind energy, and wind farms and watch some videos about Wind Farms in Wyoming.

But First...the basics...

What is Wind? Wind is air in motion.

What makes the wind?
Would you believe that the sun makes the wind? The sun unevenly heats the different surfaces of the earth. (Land heats up and cools off faster than water.) As the air over land gets warmer, the particles spread out, become less dense and rise. The air cools as it it rises above the land. It then becomes more dense and sinks.

As warm air rises, cooler air rushes in to fill in the place of the heated air. This moving air is the wind. The process of rising and sinking air is called convection.

The seasons and the shape of the land, called typography, affect convection.

Read more

Wind is called a renewable energy source because the wind will blow as long as the sun shines. Renewable energy is made from resources that can be replaced in a short time. It is also called "clean energy" or "green power."

Non-Renewable Energy sources are those that are gone forever once we use them up. Most are fossil fuels, formed from plants and animals that were buried millions of years ago. They cannot provide energy forever.

How much renewable energy do we use?

Find out with this multimedia slide show

Take all these Renewable Energy Fieldtrips with video, for more facts.

The History of Using Wind Power

People began to use the power of the wind a long time ago. In 5000 BC, wind powered sail boats on the Nile River. They developed windmills to grind grain and pump water. Countries made fleets of sailing ships to trade and explore the world.

In 1888 used the first windmill generated electricity in Cleveland, Ohio. These windmills started to be called "wind turbines."

Check out the wind energy Timeline from the Energy Kid's Page.

Wind Power Today
Today, wind is used to make electricity, and wind turbines and wind farms are becoming familiar sights.

How Do Wind Turbines Work?
A wind turbine has 3 parts that we can see: the tower, the blades and and a box behind the blades, called the nacelle. Wind energy spins the blades on a wind turbine which generates electricity. It spins something like a pinwheel. The blade is shaped something like an airplane wing so that air pressure is lower on one side than on the other. This difference in air pressure creates lift, which forces the blade to move.

Inside a wind turbine

The 3 rotating blades of the turbine are connected at the hub. The blades and hub are called the rotor.The rotor connects to a drive shaft. The drive shaft goes through a gear transmission box and attaches to a high speed shaft which turns a generator that makes electricity. (This happens inside the nacelle). Large turbines have controls that orient the blades into the wind.

The electricity is sent through transmission lines and distribution lines to a substation, then on to homes, business, hospitals and schools.

The Power Grid...interactive lesson

See a wind turbine in action at the US Department of Energy Web site: Wind Turbine Animation

Take the crash course in wind energy and learn how a wind turbine works. Identify the parts of a wind turbine.

How tall are wind turbines?
Wind speed increases as the height from the ground increases. Ground friction and objects on the ground hinder the flow of the wind. More wind speed generates more electricity. Scientists estimate a 12 percent increase in wind speed with each doubling of elevation. The large turbine rotors vary from 50 to 90 meters . Small wind turbines rotors are 8 meters or less and are mounted on towers of 40 meters in height or less.

How fast do the blades rotate?
Between 8-16 mph...and they turn off at about 45-65 mph so they won't be damaged in storms or high winds. The turbine has a brake that will keep the blades from turning too fast.

How many rotations do the blades make in a minute?
30-60 rotations/min

How much power can one wind turbine generate?
The unit of measurement for electricity is called a watt (W). A kilowatt (KW) is 1000 watts. A million watts is called a megawatt (MW). A wind turbine can generate from 250 watts to 5 megawatts of electricity, depending on its size and location. Smaller wind turbines are used for providing power off the grid: such as powering a ranch or dairy farm, or remote villages, charging up batteries on a sailboat, or powering a school. A megawatt of wind generates about as much electricity as 225 to 300 households use in a year.

A turbine may run for 6000 hours a year for 25 years!

How do you know where to put a wind farm?

Some critical factors to consider are: How fast, how often, and how much reliable wind there is? Are there seasonal variations? Does zoning allow a wind farm? Is it near transmission lines? Consult a more complete checklist of factors.

The energy from the wind rises as a cube of wind speed. In other words, if wind speed doubles, the power output increases eight times. Choosing the best location can make a difference.

Geographic location is very important when determining if there is enough wind. The best places are gaps in mountains, open plains, tops of rounded hills and, especially, shorlines. The top 10 states in wind resources are: North Dakota, Texas, Kansas, South Dakota, Montana, Nebraska, Wyoming, Oklahoma, Minnesota and Iowa. You need an average wind speed of around 25 km/h.      

10 steps to building a wind farm.

One of 30 wind turbines in the United Kingdom's Kentish Flats offshore wind farm, which produces up to 90 MW.

Tools for Estimating Wind Resources

• Mt Washington Beaufort Scale

• Wind Rose

• Wyoming Wind Resource Map

• United States Wind Resource Map

The challenges of the future for wind power are to cheaply produce machines that can produce power at lower wind speeds!