Wind Generator Facts
1. Noise:
Today's large wind turbines make less noise (about 45 decibels-dB) than
the background noise you hear in your own home (50 dB)! According to the American Wind Energy Association (AWEA), today an
operating wind farm at a distance of about 750 to 1,000 feet is no noisier than a kitchen refrigerator or a moderately quiet
room. Careful placement of these turbines can justify this clean energy turbine.
2. Bird Kills:
Although birds do infrequently collide with turbines, wind energy poses
less of a threat to birds than many other commonplace structures. In fact, the National Audubon Society has stated that it
supports the development and use of wind power. Based on numerous studies that have taken place in New York, Oregon, Vermont,
Colorado, Wyoming, Minnesota, and California, collision with turbines result in 1-2 bird deaths or less per turbine per year.
For comparison, each year at least 60 million birds die in collisions
with vehicles; at least 98 million in collisions with buildings and windows; and at least 4 million in collisions with communication
towers. Important consideration should be given to placement of wind turbines to ensure that turbines are not located along
migratory bird flight paths or the flight paths of threatened or rare species. In another study, it has been estimated that
ordinary house cats worldwide kill between 100-200 million birds, compared to 33,000 birds killed by Wind farm collisions
worldwide.
3. The alternatives:
Consider this; bird deaths that result from fossil energy based power
production:
Tall smokestacks- A study at a single Florida coal fired power
plant with four smokestacks recorded an estimated 3,000 bird kills in a single night during a fall migration.
Oil spills at sea - In a single oil shipping accident, - the
Exxon Valdez oil spill in Alaska's Prince William Sound - more than 500,000 migratory birds perished, or about 1,000 times
the estimated annual total in California's wind power plants.
Additional threats to birds from other energy sources include:
mercury emissions from coal fired power plants; global climate change resulting from the combustion of fossil fuels; acid
rain resulting from coal fired power plant emissions of SO2 and NOx and; destruction of habitat as a result of mining activities
associated with the coal, gas, oil and uranium industries.
4. Property Values:
Views of wind turbines will not negatively impact property values. A recent
study on the economic impacts of wind power states that, "based on a nation-wide survey conducted of tax assessors in other
areas with wind power projects, we found no evidence supporting the claim that views of wind farms decrease property values."
Other studies conducted in both the US and abroad, have made similar findings.
5. Opposition to wind energy projects?
Local opposition to proposed wind farms usually arises because some people
perceive that the development will ruin the view that they are use to. It is true that a large wind farm can be a significant
change, but while some people express concern about the effect wind turbines have on the beauty of our landscape, others see
them as elegant and beautiful, or symbols of a better, less polluted future. The visual effect of wind farms is a subjective
issue, but most of the other criticisms made about wind energy today are exaggerated or untrue, and simply reflect attempts
by particular groups to discredit the technology, worry local communities, and turn them against proposed projects. With the
internet the negativity can spread like crazy.
6. Tourism and Income:
In North Carolina, a study to determine public attitudes towards wind
energy was recently conducted. The study found that 77.1% of participants who had seen first hand a utility scale turbine
said that they liked its appearance. 7 Studies from numerous US states and other countries report that a majority of people
think wind turbines are graceful, elegant structures. Many people find turbines to be interesting features in the landscape,
enhancing the vista overall. In the UK, the British Wind Energy Association notes that wind farms are popular tourist attractions,
with thousands of people each year flocking to visit attractions.
7. Pollution Prevention:
A single 750 kilowatt wind turbine, operated for one year at a site with
Class 4 wind speeds, can be expected to displace a total of 2,697,175 pounds of CO2, 14,172 pounds of sulfur dioxide, and
8,688 pounds of NOx.
8. Wind energy is economically competitive.
With today’s rising coal and gas prices, new wind plants compete
favorably against any new electricity generation source. In fact, when the Colorado Public Service Commission issued a ruling
on the 161-megawatt (MW) wind project in Lamar, Colorado, the commission determined that wind energy provided the lowest cost
of any generation resource submitted to a solicitation bid by Xcel Energy. The commission also noted that unlike the other
generation resources considered, the Lamar project avoided a future risk of increased fuel prices.
9. Wind energy is a valuable crop of the future for farmers and ranchers.
Wind farms located in rural areas generate energy that can be transmitted
to load centers in urban areas via the regional utility grid. The rural areas retain the jobs, as well as land lease revenue
for farmers and ranchers (as much as $4000 per turbine per year). Wind turbines are compatible with rural land uses—crops
can be grown and livestock can be grazed up to the base of the turbine. Wind energy also provides an increased local tax base
for rural areas. One wind project increased its local tax base by $32 million. The 912 MW of new wind power installed in Texas
in 2001 will deliver $13.3 million in tax revenue for schools and counties.
10. Unlike most other electricity generation sources, wind turbines
don’t consume water.
Irrigation and thermal electric generation account for approximately 77%
of U.S. fresh water use. Conventional plants generating power from fossil and nuclear fuels use large amounts of water for
cooling; wind turbines do not use water. That makes wind energy a great choice for farm lands.
11. Wind energy is an indigenous, renewable energy source that contributes
to national security.
The United States is the world’s largest importer of oil and natural
gas, which often originate in troubled areas of the world. The Great Plains region, which has been dubbed “the Saudi
Arabia of wind” because of its tremendous untapped wind energy potential, offers home grown energy, which increases
national security. Reliance on indigenous resources also reduces the balance of payments that threatens our national economic
security. Because of the distributed aspect of wind energy, it is less vulnerable than large liquefied natural gas (LNG) ports
or large thermoelectric power plants.
12. Shadow Flicker
Wind turbines, like other tall structures will cast a shadow on the neighboring
area when the sun is visible. If you live very close to the wind turbine, it may be annoying if the rotor blades chop the
sunlight, causing a flickering (blinking) effect while the rotor is in motion.
A bit of careful planning, and the use of good software to plan your wind
turbine site can help you resolve this problem, however. If you know where the potential flicker effect is of a certain size,
you may be able to place the turbines to avoid any major inconvenience for the neighbors.
This is occasionally raised as an issue by close neighbors of wind farm
projects. A wind turbine's moving blades can cast a moving shadow on a nearby residence, depending on the time of the year
(which determines how low the sun is in the sky) and time of day. It is possible to calculate very precisely whether a flickering
shadow will in fact fall on a given location near a wind farm, and how many hours in a year it will do so. Therefore, it should
be easy to determine whether this is a potential problem. Normally, it should not be a problem in the U.S., because at U.S.
latitudes (except in Alaska) the sun's angle is not very low in the sky, and the appropriate setback for noise will be sufficient
to prevent shadow flicker problems.
Fortunately, we are able to predict quite accurately the probability of
when and for how long there may be a flicker effect. We may not know in advance whether there is wind, or what the wind direction
is, but using astronomy and trigonometry we can compute either a likely, or a "worst case" scenario, i.e. a situation where
there is always sunshine, when the wind is blowing all the time, and when the wind and the turbine rotor keep tracking the
sun by yawing the turbine exactly as the sun moves.
13. What about turbines throwing blades, or ice? Is wind energy dangerous
to the public?
It has been estimated by a number of reliable sources that 50,000 Americans
a year die from air pollution, of which about one-third is produced by power plants. By contrast, in 20 years of operation,
the wind industry (which emits no pollutants) has recorded only one death of a member of the public--a German skydiver who
parachuted off-course into an operating wind plant. Blade throws were common in the industry's early years, but are unheard
of-today because of better turbine design and engineering. Ice throw, while it can occur, is of little danger because setbacks
typically required to minimize noise (see above) are sufficient to protect against danger to the public, and because ice buildup
slows a turbine's rotation and will be sensed by a turbine's control system, causing the turbine to shut down. One European
group that has investigated the ice throw question recommends a setback of 1.5 times the sum of a turbine's hub height and
its rotor diameter.
14. How much water do wind turbines use compared with conventional
power plants?
Water use can be a significant issue in energy production, particularly
in areas where water is scarce, as conventional power plants use large amounts of water for the condensing portion of the
thermodynamic cycle. For coal plants, water is also used to clean and process fuel.
According to the California Energy Commission (cited in Paul Gipe's Wind
Energy Comes of Age, John Wiley & Sons, 1995), conventional power plants consume the following amounts of water (through
evaporative loss, not including water that is recaptured and treated for further use):
WATER CONSUMPTION--CONVENTIONAL POWER PLANTS
Technology
gallons/kWh liters/kWh
Nuclear
0.62 2.30
Coal
0.49
1.90
Oil
0.43 1.60
Combined Cycle Gas 0.25
0.95
Small amounts of water are used to clean wind turbine rotor blades in
arid climates (where rainfall does not keep the blades clean). The purpose of blade cleaning is to eliminate dust and insect
buildup, which otherwise deforms the shape of the airfoil and degrades performance. Similarly, small amounts of water are
used to clean photovoltaic (solar) panels. Water use numbers for these two technologies are as follows:
WATER CONSUMPTION--WIND AND SOLAR
Technology gallons/kWh
liters/kWh
Wind [1]
0.001
0.004
Solar [2]
0.030
0.110
Wind therefore uses less than 1/600 as much water per unit of electricity
produced as does nuclear, approximately 1/500 as much as coal, and approximately 1/250 as much as natural gas, the most popular
choice for new power plants.
1. American Wind Energy Association estimate, based on data obtained
in personal communication with Brian Roach, Fluidyne Corp., December 13, 1996. Assumes 250-kW turbine operating at .25 capacity
factor, with blades washed four times annually.
2. Meridian Corp., "Energy System Emissions and Materials Requirements,"
U.S. Department of Energy, Washington, DC. 1989, p. 23.
Below are some examples of the power created by wind farms across the
United States
Worth County, Iowa
In February 2001, Alliant Energy signed a long-term contract to purchase
80 mega watts of electricity - enough to supply approximately 25,000 homes - from the Top of Iowa Wind Farm near Joice, Iowa.
The facility was co-developed by Zilkha Renewable Energy and Midwest Renewable Energy Corporation, with turbines purchased
from NEG Micon.
Hancock County, Iowa
The Hancock County Wind Energy Center became one of the largest commercial-scale
wind farms in Iowa when it began operation in December 2002. The 148 Vestas turbines produce 98 MW of electricity, enough
electricity for about 40,000 homes. Alliant Energy is one of four utilities purchasing power from the facility. The total
land used for all 148 turbine foundations and access roads is about 60 acres. The Hancock County facility is owned and operated
by FPL Energy.
Buena Vista County, Iowa
In September 1999, the Storm Lake Wind Power Facility was dedicated in
Alta, Iowa. Alliant Energy purchases 80.25 mega watts of electricity generated from 107 turbines, enough energy to power nearly
40,000 homes. One of the world's largest wind farms, the Storm Lake Wind Power Facility consists of 260 turbines capable of
producing 193 mega watts — providing enough electricity to power 72,000 Midwestern homes
Wilmont Hills, Minnesota
The first wind facility built specifically for Alliant Energy’s
Second Nature™ renewable energy program went online in February 2002. Alliant Energy contracted with Northern Alternative
Energy to develop the facility, which contains a single three-bladed, 1.5-megawatt turbine. The tower stands 230 feet tall
to the hub, and its blades stretch 236 feet across. The turbine provides 4.5 million kilowatt-hours of electricity a year,
enough to power about 450 homes. It stands on a 220-acre farm owned by Leon and Dolores Sieve.
Iowa County, Wisconsin
In April 2001, Alliant Energy announced an agreement with FPL Energy to
purchase 4.5 MW of new wind generation capacity in Wisconsin. The Montfort Wind Farm, located in Iowa County near Eden, is
the largest wind facility in Wisconsin. The facility includes of twenty 1.5-megawatt wind turbines. The turbines stand on
215- foot towers and are outfitted with 100-foot blades. The capacity of the wind farm totals 30 mega watts – enough
to power 100,000 homes.
Cerro Gordo County, Iowa
The Cerro Gordo Wind Farm near Ventura in north central Iowa began providing
clean electric energy to Alliant Energy customers in May 1999. Alliant Energy has contracted with FPL Energy to purchase all
electricity produced on the Cerro Gordo facility for a 20-year period. The Cerro Gordo Wind Farm spans 2,110 acres and has
a generating capacity of 42 mega watts. Fifty-five turbines occupy only 2.4 acres and have a minimal effect on farming. More
than 10 miles of underground cables link the turbines and transmit electricity to a nearby substation.
How much energy can a single turbine or wind farm produce?
1. A single 1.8 Mega watt turbine in one year can produce 5.0 million
Kwh's of electric and supply enough power for 500 homes
2. (20) 1.8 Mega watt turbines in one year can produce 2 Billion Kwh's
of electric which is enough electric for 10,000 homes
3. (20) 1.8 Mega watt turbines over twenty years can produce 100 billion
Kwh's of clean electric generation and provide enough electric for 10,000 homes for those twenty years.
An authors opinion of new wind turbines
My name is Shawn Lessord, and I would like to personally thank you for
taking the time and gaining the knowledge of renewable energy and wind power.
I personally have a small Southwest Wind Power AIR-X electric turbine
which has been installed for several years on our home. Below are some of my thoughts on the issues being raised about residential
wind turbines.
Do wind electric turbines make a lot of noise?
Answer: Most wind electric turbines make a swooshing noise that is very
low in sound or decibels (db). Usually a turbine sound cannot be heard over 500' feet from the turbines base, so set backs
can basically mask any possible noise that could be heard.
The DB level is usually under 50 decibels for the larger turbines and
much less for the smaller residential turbines, which is close to a normal conversion between two people. Many people say
that small residential type wind electric turbines make very little noise, and the sounds of other noises such as trees blowing
usually mask the pinwheel like sound that these turbines make. I have a wind electric turbine in a residential development
and my neighbors did not know I had it until two years after it was installed. In fact, others who walk on a regular basis
have commented that they did not know it was up on our roof. Please note this is a very small turbine and will only produce
400 watts of power. There are other residential turbines which will produce power up to 10Kw or 10,000 watts.
Do turbines throw ice during the winter months?
As you know ice falls from trees, power lines, and buildings, and wind
turbines are no exception, they do. Usually most turbines are sited to be located where people cannot be near these large
turbines. In the case of our residential turbine, I have never seen a case where ice has fallen from our turbine that is located
on our home. My honest thoughts are that, if installed in the proper way they are absolutely safe. In fact, ours is located
on the roof of our home above my own daughter’s bedroom. I take great pride to say that safety comes first and it has
never been an issue.
Can you be electrocuted by a wind turbine?
The answer is not likely. All electrical wiring both commercial and Residential
are inspected and approved by a certified inspection agency. All wind grid connected systems have to go through a series of
(3) inspections to be approved to connect to the grid. All inspections have to be NEC (and ESA in Ontario) compliant and are
tested to make sure they meet these strict standards. This applies to both residential and commercial wind generating systems.
Can birds fly into the turbines?
Although I have yet to see this happen on our installed residential turbine,
I have been told that it will happen with the larger turbines. I always tell people that these turbines should be carefully
placed in locations to prevent migratory birds from being struck. Many of the bird kills were caused by the older wind turbines
when the speed of the blades was much faster. Now with new technology this has greatly improved. I also have never seen any
bird in the many years our turbine has been installed get killed by it; however I have seen birds hit our picture window on
several occasions.
Other thoughts!
When asked if I think wind energy is a viable source of renewable energy,
I say yes! I also let people know the advantages to green power generation, and how turbines can eliminate carbon emissions
and make green energy for a better tomorrow.
