Sail boats, wind mills, kites, and weather vanes are examples of every day items that move, or fly because of the kinetic energy of wind. Wind has been a source of power used by people for years dating back to the early ages of civilization. We actively feel, use and depend on wind, but do you understand where and how wind works? Here is a simple explanation of this common earthly feature:
Air floating over land is warmed by the solar heat during the day. This warming effect causes the air to rise because it is less dense. As it rises, cold air over water flows in to fill the void. At night it is the opposite effect. The sun goes down, the land cools down. The air sinks over land and rises over water. This daily pattern is a continuous movement of air masses that cross the globe. This motion is what we call wind. Land features such as mountains, hills, valleys, prairies increase or decrease the velocity of the wind, creating a variety of speeds depending on location. Also, the west-east rotation of the earth attributes to the motion of wind. Known as the Coriolis Effect, in the Northern Hemisphere the wind follows the rotation of the earth. In the Southern Hemisphere, the wind follows the counter rotation flowing east-west. So, summarized: the heat provided from our sun and the rotation of the earth provide the wind we rely on.
Over the years, people have found a way to capture the energy of wind to produce electricity. These structures are called wind turbines. Modern wind turbines come in a variety of sizes, shapes, and styles. Typically, turbines consist of blades or some form of a rotating head and a drive shaft connected to a generator. The rotating head creates drag against the wind turning the drive shaft which produces electricity through the generator. With enough turbines on several acres of land the area is called a wind farm. PA has a few wind farms such as:
- Armenia Mountain (Bradford and Tioga County) 67 Turbines
- Locust Ridge II (Columbia and Schuylkill County) 51 Turbines
- Waymart (Wayne County) 43 Turbines
- Allegheny Ridge (Blair and Cambria County) 40 Turbines
All of the wind turbines you see at these sites are “horizontal-axis wind turbines” or “HAWT’s” because the axis of their rotation is parallel to the ground. Find out about other Wind Farms in PA at www.pennfuture.org or www.pawindenergynow.org.
At Tanoma Wetland AMD site, we have a prototype vertical-axis wind turbine (or a VAWT). This prototype is approximately 15 ft. tall and 14 ft. across. It turns at slower vane speeds, harbors minimum threats to wildlife, and is more aesthetically pleasing. This turbine will be connected, in the future, to a generator, to provide electricity for aerators. It is anticipated that the wind turbine will produce an estimated 400 watts through the generator. Check out our short video of the turbine in action below or take a trip to Tanoma and see it in person. Get directions by following this link: http://www.evergreenconservancy.org/?page_id=108.
Wind Power Kid Activities
We have provided two activities for kids to get interested in wind power by creating their own turbines. Adult supervision and help may be needed for younger kids.
Materials: scissors, aluminum pie plate, permanent marker, glass/bottle with small opening, puddy, needle, pen cap, 4 tea lights, matches
- Cut the edging off the aluminum pie plate so all that’s left is a flat disc.
- Mark out 8 equal length slices. Cut each slice, but stop cutting 1” from center of pie plate. Making sure they are all still attached near center of pie.
- Slightly twist each cut piece in same direction to encourage the disk to turn as air moves past.
- Cut the tail off of the pen cap and push the pen cap through the center of the pie plate.
- Roll the puddy into a ball and put into hole of bottle/glass with sharp end of needle sticking up through puddy.
- Set pen cap on top of needle, trim pie plate or adjust needle length if plate does not sit evenly (pie plate needs to be evenly free spinning above puddy).
- Place the 4 tea lights evenly around bottle, all directly under pie plate touching the bottle.
- Light the tea lights and see the turbine spin as the air warms and moves the aluminum plate.
Materials: stiff paper, scissors, thumbtack, drinking straw
- Cut a square of any size out of the stiff paper. All sides should be cut to equal lengths.
- Cut equal length slices from each corner cutting towards the center of the paper. Make sure you don’t cut into the center.
- Pin up each right corner in center of paper with thumbtack.
- Push thumbtack into side of straw.
- Blow along the side of the paper windmill and see it spin around.