Wind power is the
world's fastest growing electricity generation technology. Wind is a renewable
resource because it is inexhaustible. It is a result of the sun shining
unevenly on the earth. The corresponding daily and seasonal changes in
temperature consistently generate wind, producing a fuel source that can
never be depleted.
wind power plants use large spinning blades to capture the kinetic energy
in moving wind, which then is transferred to rotors that produce electricity.
At the best wind fuel sites, wind plants today are nearly competitive
with the conventional natural gas-fired combined-cycle plants -- even
when natural gas prices have recently been at historically low levels.
Regions where average wind speeds exceed 12 miles per hour are currently
the best wind power plant sites.
Current costs of
wind-generated electricity at prime sites approach the costs of a new
coal-fired power plant. Wind
power is the lowest-cost renewable energy technology available on the
market today. According to the Department of Energy, the costs of wind
power are projected to continue to fall and may rank the cheapest electricity
source of all options by 2020.
What are the environmental
Wind plants produce
no air pollution. They use no water, and there is no need to tear up the
land to extract the wind resource that produces wind power. Nonetheless,
there may be environmental problems associated with some wind plants.
Wind power generates
three categories of environmental impacts: visual
impacts; noise pollution; wildlife impacts. These impacts can vary immensely
from site to site.
- Because wind farms are comprised of large numbers of turbines each
mounted atop tall towers in rural areas, they can often be seen for
a long distance. Whether this visual impact is good or bad will vary
from location to location. Some find wind turbines to be enduring symbols
of self-sufficiency. Others see them as stark intrusions in the "natural"
- Wind turbines, particularly older designs, emit noise that can be
heard in the vicinity of the wind farms. The level of noise produced
by one wind turbine is equivalent to that of your washing machine. The
frequency and volume of this noise can be controlled but not eliminated
by wind turbine design.
The most controversial significant negative environmental
impact of early wind turbines is the impact on bird populations, an
issue largely resolved by new turbine designs.
- In the early 1980s, three major wind farms were built in passes in
California. At the Altamont Pass site, deaths of birds, particularly
raptors, prompted a number of studies that subsequently influenced both
the design of newer wind turbines and the siting of wind farms. It was
discovered that raptors perch atop the wind generators for a better
view while hunting, and upon rare occasion get caught in the spinning
blades when the wind begins to blow. Current wind turbine technology
offers solid tubular towers to prevent birds from perching on them.
Turbine blades also rotate more slowly than those of earlier designs,
reducing potential for collisions with birds.
If wind power plants
are sited in regions screened for sensitive local bird populations, the
environmental footprint of wind-generated electricity is quite small when
compared to the wildlife and ecosystem impacts of fossil fuel mining and
The manufacture of
wind generation technology creates some air emissions.
American Wind Energy Association http://www.awea.org/
National Wind Coordinating Committee http://www.nationalwind.org/
National Renewable Energy Laboratory: National Wind Technology Center http://www.nrel.gov/wind/
CA Energy Commission / Wind http://www.energy.ca.gov/wind/
Danish Windpower Manufacturers http://www.windpower.dk/
European Wind Energy Association http://www.ewea.org/
Union of Concerned Scientists: How Wind Energy Works http://www.ucsusa.org/clean_energy/renewable_energy/page.cfm?pageID=80
Natural Resources Defense Council Wind Fact Sheet http://www.nrdc.org/air/energy/fwind.asp
Minnesotans for an Energy Efficient Economy: Wind Site http://www.me3.org/issues/wind/
Wind Energy for Electric Power: A REPP Issue Brief. Renewable Energy Policy Project. November 2003. http://crest.org/articles/static/1/binaries/wind%20issue%20brief_FINAL.pdf