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One of the
most important alternative energy resources can’t be seen or
touched, but its power is obvious to anyone who’s ever weathered
a hurricane, a tornado, or even a strong storm. At its worst, wind
can wreak havoc, destroying everything in its path. At its best,
it’s a source of clean, efficient, inexpensive energy. Explore
more about ways to harvest the power of the wind.
 The
sun heats up the atmosphere, which causes it to expand. As the atmosphere
expands it moves cooler air out of the way. The movement of these
hot and cold air currents is what makes up wind. Because wind is
moving all of the time, it is a type of kinetic energy we can use
if we are able to harness it.
History
People
have used the wind’s power for thousands of years. Wind powered
mills used to grind grain and to pump water. Wind was a primary
power source up until the Industrial
Revolution, when its importance decreased dramatically. Inventions
like the steam engine and steam turbine provided cheaper and more
reliable power sources. Energy created by steam fulfilled an ever-increasing
demand for electricity, blowing away wind’s leading role as
a power source.
How
it Works
 Wind
is part of the cycle of energy that starts with the sun itself.
The sun’s energy heats the earth’s surface unevenly. Warmer
air rises drawing in cooler air and resulting in wind. The way we
capture the energy of the wind hasn’t changed much since the
very first windmills turned. We still use turbines, but instead
of using the wind’s energy to do work like grinding grain or
pumping water, wind’s energy is now used to produce electricity.
The force of the wind turns the blades of a turbine.
The turbine is attached to a generator,
which spins, producing electricity . In order to produce electricity
on a large scale, groups of turbines are placed together in arrays
called wind farms.
Efficiency
 Not
all of the wind’s potential energy can be extracted during
the electrical generation process. The amount of energy available
in a resource compared to the amount of energy actually extracted,
is the efficiency of that resource. In wind’s case,
it’s maximum efficiency is about 59%. Physical factors defined
as the Betz limit mean not all the energy can be captured. While
the basic process hasn’t changed since the earliest windmill
blades turned, changes have occurred allowing for improved efficiency.
Better blade design and lighter and stronger materials mean more
energy extraction. The current turbine designs allow for 35-45%
efficiency, leaving room to reach the maximum efficiency of 59%.
That improvement should come as designs and materials develop even
further.
Benefits
 Wind
power has many benefits
- Environmental:
Like many other renewable resources, the wind contributes no emissions
or waste to the environment. By using wind power instead of burning
coal for example, 1 billion pounds of C02
can be kept out of the atmosphere.
- Economic:
For power companies, the wind is essentially a "free"
fuel. It doesn’t need to be purchased or transported. The
cost comes in the form of the turbines. For farmers, wind can
provide a new source of income, as power companies often pay "rent"
to place turbines on tracts of land in windy regions. Since a
wind turbine takes up only about a half an acre, the land is doing
double duty for the farmer who is harvesting two "crops"
from the same land. For communities, wind farms can provide important
economic development. Many wind farms are built in rural areas,
and provide good-paying jobs for residents.
Limitations
So
why isn’t everyone exploiting this "free" resource?
- Speed—One
of the main limitations of wind power is that the wind doesn't
blow fast enough all of the time. Since wind speed directly affects
power output, you end up with unpredictable power levels.
- Reliability—You
simply can’t control whether the wind will blow. No wind,
no power.
- Storage—Currently,
electricity can’t be stored efficiently, so wind power can’t
be relied on as a power source free of interruptions.
Beyond the control factors, are aesthetic ones.
- Looks—Not
everyone looks at a wind farm and sees the energy potential. Instead
they see a cluttered and unattractive landscape.
- Noise—Critics
also point to the noise level created by wind farms. Some people
don’t notice the noise, to others it’s bothersome.
- Danger—A
widely held belief, that’s scientifically unsupported, is
that wind turbines kill a lot of birds. Studies have shown that
electric lines actually kill more birds than turbines do, although
it would be unwise to site a wind farm in a migratory path.
Geographical
Considerations
 When
it comes to energy production, the wind is considered a resource
that’s specific to certain areas. Just like Texas is rich in
oil, the upper Midwest is rich in wind. The wind is constant enough
and at a high-enough speed to make wind farming sensible and economically
efficient for that region.
 Check
it out!
Check this
link for a map of
average annual
wind power
in areas of the United States from the Renewable Resource Data Center.
Several factors
have to be taken into consideration when considering if a site is
a good choice for a wind farm.
- Wind
speed—Does
the wind blow fast enough and consistently enough to produce power?
- The
physical landscape
is also taken into consideration. The best place to site a turbine
is on top of a ridge or hill, so that it’s capturing the
most wind possible.
- Access
to the electrical grid—Are
there transmission lines close enough to the turbines to distribute
the electricity generated? Many of the places richest in wind
are extremely rural, and the electrical grid might be far away.
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What
do you think?
Some people think
wind turbines are ugly. Others find them beautiful. What is
your opinion? Should the appearance of wind farms limit where
they are used? Can wind power play a significant role in meeting
our future energy needs?
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Sources
- American Wind Energy Association. "Iowa School
District to Receive Wind Energy for Christmas." (Online) http://www.awea.org/wew/828-1.html.
June 2001.
- American Wind Energy Association. "Vast Wind
Potential in the Great Plains." (Online) http://www.awea.org/outlook2000/outlook_8.html.
July 2001.
- Solarbuzz Inc. "Solar Energy Industry Statistics:
Market Share." (Online) http://www.solarbuzz.com/StatsMarketShare.htm.
July 2001.
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Not in My
Backyard….
 It’s
easy to claim to support renewable energy resources like wind power.
But showing that support often means making tough decisions. Take
the proposed project off the coast of Cape Cod. More
Iowa
Schools Use Wind Power
 Several
Iowa schools learned a lesson about lessening their energy bills,
by installing wind turbines. The clean, efficient generators help
schools save money and contribute to the classrooms as well. More
World
Class Wind
 One
of Iowa’s claims to fame is as home to the world’s largest
wind farm. More
IPTV Market
to Market Links
Benefit
found in small scale wind projects
wind researchers have often called the upper Midwest the Saudi Arabia
of wind power. If the wind potential for the entire region were
completely utilized, it is estimated the energy produced would supply
more power than the entire united states could use.
Experts discuss
Wind
power.
Web
Links
Largest
Land-based Wind Project will be Built in Iowa
Midamerican Energy plans to build 310 megawatts of wind generation
facilities in northwest or north-central Iowa by 2006. The $323
million project will be the largest land-based wind project in the
world, according to the U.S. Department of Energy.
Iowa
Wind Energy Development Projects
Keep up-to-date with current and new wind projects in the State
of Iowa.
What
are the average wind speeds each month in Iowa
The answer is blowin' in the wind. See full color maps illustrating
usable wind speeds.
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