WIND POWER
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.
California has been a leader in using wind power, due
to their available wind resources in mountain regions, and their
expanding need for electricity. Wind energy supplies one percent
of the state's electricity. California's wind plants extend over
more than 27,000 acres, yet only 10-15 percent of the area is
actually occupied by the turbines. The blustery region just east
of the San Francisco Bay area boosts more wind turbines than
anywhere else in the world, nearly half of the state's total.
The basic principles of wind turbines is 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.
Several electric utilities and communities have recently
launched wind power programs.
EXAMPLES:
- Traverse City Mich. supplies power to 170 homes and
businesses, which pay an additional 1.58 cents per
kilowatt-hour, or about $7.58 per month. Their wind
generator features 144-foot long blades perched on a
160-foot tower. With winds in that area averaging about 14.5
mph, it generates about 1.2 million kilowatt hours of
electricity a year, enough for about 200 homes.
- In 1993, Iowa's Waverly Light & Power installed and
began operating an 80-kilowatt wind generator for a
population of 9,000. The $129,000 system demonstrates how a
small utility can own and operate wind generation. Alta,
Iowa also broke ground in 1998 for a $200 million wind farm
with 259,750 kilowatt turbines, the largest in the U.S. to
date.
- Great River Energy in Minnesota (formerly United Power
& Cooperative Power). This power supplier began by
pre-selling 3,750 "blocks" of wind generated power
to interested consumers (1 block = 100 kilowatt-hours).
Businesses and home owners have contracted to pay $2 extra
per month for each 100-kWh block of green power that they
use. Now that all the needed energy has been sold, Great
River is building the $1.7 million wind farm in southwestern
Minnesota
- Altamont Pass and two smaller wind farms, all located in
California, produced enough energy to power a city the size
of San Francisco. That's 2.8 billion kWh of electricity, or
the equivalent of about 5 million barrels of oil.
- One California-based turbine manufacturer, U.S. Windpower,
joined forces with Iowa-Illinois Gas & Electric to set
up wind farms on agricultural land. This will generate about
250 megawatts for area utilities and benefit 100,000 homes.
- Marshall (MN) Municipal Utilities and Minnesota Windpower
worked and installed five 12-kilowatt (kW) wind turbines on
city property, to serve 12,000 homes.
- Wind resources throughout the U.S. in relation to
physical characteristic land surfaces:
- Highest wind energy (class 7): Alaska (the Aleutian
Islands and coastal areas of western 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
Utility Wind Interest Group www.uwig.org
National Wind Coordinating Committee www.nationalwind.org
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