1. Alysse Riggs and Julie Davis

2. General Information In reality, wind energy is a form of solar energy The sun's radiation heats different parts of the earth at different rates when different areas absorb or reflect at different rates. Hot air rises, reducing the atmospheric pressure at the earth's surface, and cooler air is drawn in to replace it. Air has mass, and when it is in motion, it contains the energy of that motion("kinetic energy")

3. The Main Goal To create alternative energy that was renewable That did not create pollution in the air and water That could replace nonrenewable sources and pollution in the near future http://www.4ecotips.com/eco/img0 906/Quietrevolution.jpg

4. Making A Difference It is a clean source of renewable energy that does not create air or water pollution The biggest wind turbines can power over 600 houses Global capacity was approximately 70,000 megawatts (1 megawatt can power over 250 homes) By 2050 the answer to one third of the world's electricity needs will be found blowing in the wind. http://windeis.anl.gov/guide/photos/photo2.html

5. The Wind Turbines Two Groups of wind turbines: horizontal-axis turbine and vertical-axis turbine (egg-beater) Turbines are made of steel. The blades are made of fiberglass- reinforced polyester or wood- epoxy. The output of a wind turbine depends on the turbine's size and the wind's speed through the rotor. http://windeis.anl.gov/guide/basics/index. cfm http://www.sextonwindpower.com/files/wi nd_turbine_drawing(1).gif

6. Wind Turbines Cont. A wind energy system transforms the kinetic energy of the wind into mechanical or electrical energy Electricity production and consumption are most commonly measured in kilowatt-hours (kWh). A kilowatt-hour means one kilowatt (1,000 watts) of electricity produced or consumed for one hour. Ex: One 50-watt light bulb left on for 20 hours consumes one kilowatt- hour of electricity (50 watts x 20 hours = 1,000 watt-hours = 1 kilowatt-hour). http://www.solarnavigator.net/images/wi nd_turbine_aalborg.jpg

7. Technological Obstacles Wind turbines - Below 8-10 mph wind speed they do not generate and have to cut out for safety reasons above 56 mph. Their maximum generation is reached at about 30 mph. Wind Farms - generate some power for 70-75% of the time but this is often a mere trickle, so the total electricity produced is only about 26% of their full potential. The electricity produced cannot be stored and feeding it into the national grid is complex and costly – a bill ultimately paid by the consumer. Coal or gas-fired power stations are essential to maintain uninterrupted supplies of electricity when the wind is not blowing Developers claim a turbine lifespan is 20-25 years but many are being replaced after just 9-12 years – with yet larger turbines

8. Political / Economic Obstacles The electricity produced cannot be stored and feeding it into the national grid is complex and costly, which is ultimately paid by the consumer. Wind turbines are being replaced every 9-12 years which is costing more money

9. Negative Environmental Impacts A turbine 375 feet high requires a base of some 1000 tons of reinforced concrete, to say nothing of the materials needed to build service roads. Together with peat destruction on peat-rich sites, this means that wind farms can take years to pay back the carbon dioxide they release during and after construction, reducing even further their contribution to climate change. Birds unaware of wind turbines often crash into them and are killed as a result. http://www.freewebs.com/jwpaudubon/WIND%2 0TURBINE%20BIRDS.jpg