Wind Power Facts

Harnessing the power of the wind using modern wind generators is one of the most popular sources for green power. Wind is created when the sun’s rays cause temperature and air density differences between two or more air masses on the earth’s surface. To equalize these pressure differences, air is drawn to a new location, creating wind. Other geographic factors affect the speed of the wind and its consistency.
    
Wind power is becoming an economically attractive energy source because of rising fuel costs, such as gas, coal and nuclear energy. It is also an environmentally attractive source of power because wind generators don’t pollute the air or water. Extracting electric power from the wind requires the right site, a reliable machine and the flexibility of the power system to adapt to a capricious air stream.
    
Evolution of wind technology: Wind power technology has advanced in recent years from smaller, single home generators, to larger, high-powered machines of several hundred kilowatts suitable for mass deployment in megawatt-scale machines. Sitting on towers as tall as a 20-story building, these wind plants often have blades 300 feet long from tip to tip. Several wind generators are often clustered together to create wind farms.
    
The basic principles of wind turbines are fairly straightforward. A typical wind power system consists of a generator, blades, steel tower, meteorological equipment and on-site controls. Most wind generators require utility power to start and are subject to local rules/regulations.
    
Drawbacks/dangers of wind machines: Windmills can be noisy because blade tips can approach the speed of sound; many turbine blades must be regularly scrubbed to avoid impairment of aerodynamic efficiency; large wind farms need expansive tracts of land; wind is intermittent and as wind speeds drop below eight mph, electricity generation stops; rotor blades could possibly kill or injure migratory birds.
    
Wind resources throughout the U.S. in relation to physical characteristic land surfaces:

• Highest wind energy (class 7): Alaska
• Also producing high winds are isolated areas in Hawaii and the Pacific Islands and isolated, high mountain summits and ridge crests in portions of the eastern and western U.S.
• High averages of wind energy resources include (class 4 or higher): Great Plains, from the Texas panhandle and western Oklahoma to North Dakota and western Minnesota; southern Wyoming; Northwestern Montana plains; the Atlantic coast from North Carolina to Maine; the Pacific coast from Point Conception, California to Washington; the Gulf Coast along southern Texas; much of the Great Lakes shorelines; portions of Alaska, Hawaii, Puerto Rico, Virgin Islands, and Pacific Island; exposed ridge crests and mountain summits throughout the Appalachians and western U.S.; and isolated wind corridors such as the Columbia River gorge in Oregon and Washington and San Gorgonio Pass in California.

The future of wind power:
Wind power will not provide a reliable contribution to the energy mix until we can store excess electricity generated on windy days for use when the wind doesn’t blow. However, wind energy’s environmental benefits, coupled with dramatic cost reductions in turbines and an increase in their reliability, are causing increases in wind projects being proposed to decision-makers and communities throughout the United States. For more information and available publications on wind power, refer to the sources below:

National Renewable Energy Laboratory
www.nrel.gov

Energy Efficiency and Renewable Energy Program
www.eere.energy.gov
Select the “Deployment” tab at the top to access the “Wind Powering America” program resources.

American Wind Energy Association www.awea.org
Select “Utility Scale Wind” to view a list of active wind projects in each state.

Windustry (nonprofit educational association)
www.windustry.com