Erosions
Erosion can be a concern in certain habitats such as the desert, where a hard-packed soil surface must be disturbed to install wind turbines. Erosion has also been raised as a concern in the eastern U.S., where wind farms typically must be installed on mountain ridgelines.
Solution: Standard engineering practices used by ski areas on the same kind of terrain are adequate to deal with any erosion issues that might be raised by construction of a wind farm and its service road.
Birds and bats kills
Birds occasionally collide with wind turbines, as they do with other tall structures such as buildings. Avian deaths have become a concern at Altamont Pass in California, which is an area of extensive wind development and also high year-round raptor use.
Solution: Wind’s overall impacts on birds are low compared with other human-related sources of avian mortality—see "Avian Collisions With Wind Turbines," for more information.
Affect lives of wild animals
Wind energy can also have negative impact on other wildlife by fragmenting habitat, both through installation and operation of wind turbines themselves. Also, the roads and power lines that are built will do harm to those wild animals.
Solution: This has been raised as an issue in areas with unbroken stretches of forests. More research is needed to better understand these impacts.
Noise
During early times, noise was a serious problem with wind turbine designs as it disturbed people who lived nearby a lot, but it has been largely eliminated as a problem through improved engineering and through appropriate use of setbacks from nearby residences.
Solution: Aerodynamic noise has been reduced by changing the thickness of the blades' trailing edges and by making machines "upwind" rather than "downwind" so that the wind hits the rotor blades first, then the tower
Shadow flicker
Shadow Flicker is often 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.
Solution: 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.
http://www.awea.org
American wind energy association
(Yeqi)
Friday, May 23, 2008
Thursday, May 22, 2008
Positive impacts of wind energy
Environmental
Reducing global warming
The build-up of global warming pollution is not only causing a gradual rise in average temperatures, but also increasing fluctuations in weather patterns and causing more frequent and severe droughts and floods. From specific research, US scientists find that using wind energy can help reduce total U.S. emissions of carbon dioxide by almost a third. Since carbon dioxide is the major pollutant which contributes to global warming by trapping the sun's rays on the earth as in a greenhouse, the decrease of carbon dioxide in the atmosphere means a new hope for us.
Help to prevent acid rain
Acid rain harms forests and the wildlife they support. Many lakes in the U.S. Northeast have become biologically dead because of this form of pollution. Acid rain also corrodes buildings and economic infrastructure such as bridges. Sulfur dioxide and nitrogen oxides are two most important sources of acid rain. However, development of just 10% of the wind potential in the 10 windiest U.S. states would not only provide more than enough energy to displace emissions from the nation's coal-fired power plants but also eliminate the nation's major source of acid rain.
Ensure people’s health
Particulate matter is of growing concern because of its impacts on health. Its presence in the air along with other pollutants has contributed to make asthma one of the fastest growing childhood ailments in industrial and developing countries alike, and it has also recently been linked to lung cancer. Since wind energy is a kind of clean energy, it will help contain the spread of asthma and other respiratory diseases aggravated or caused by air pollution in the country.
Protect biological food chain
Toxic heavy metals accumulate in the environment and up the biological food chain. A number of states have banned or limited the eating of fish from fresh-water lakes because of concerns about mercury, a toxic heavy metal, accumulating in their tissue. By using wind energy, it is estimated that such conditions will reduce and the negative impacts of heavy metals will be controlled.
Economical
Saving money
As with every other study of non-economic costs that has been conducted, the Externe study found wind energy's costs to be among the lowest, far below those of fossil fuels. The highest non-economic cost for wind in any European country, for example, was 0.25 Euro cents per kilowatt-hour, while the lowest cost for coal was 2-4 Euro cents/kWh (eight to 16 times as much).
Saving living area
In open, flat terrain, a utility-scale wind plant will require about 60 acres per megawatt of installed capacity. However, only 5% (3 acres) or less of this area is actually occupied by turbines, access roads, and other equipment--95% remains free for other compatible uses such as farming or ranching.
Saving water
Water is very important in energy production, particularly in areas where water is scarce. This is because conventional power plants need large amounts of water for the condensing portion of the thermodynamic cycle. Different kinds of conventional power plants consume different amounts of water. Here is a diagram which shows the water consumption of some kinds of conventional power plants (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
related wbsites:
http://www.repp.org/repp_pubs/repp_publications.html
http://www.externe.info/externpr.pdf
(He Yeqi)
Reducing global warming
The build-up of global warming pollution is not only causing a gradual rise in average temperatures, but also increasing fluctuations in weather patterns and causing more frequent and severe droughts and floods. From specific research, US scientists find that using wind energy can help reduce total U.S. emissions of carbon dioxide by almost a third. Since carbon dioxide is the major pollutant which contributes to global warming by trapping the sun's rays on the earth as in a greenhouse, the decrease of carbon dioxide in the atmosphere means a new hope for us.
Help to prevent acid rain
Acid rain harms forests and the wildlife they support. Many lakes in the U.S. Northeast have become biologically dead because of this form of pollution. Acid rain also corrodes buildings and economic infrastructure such as bridges. Sulfur dioxide and nitrogen oxides are two most important sources of acid rain. However, development of just 10% of the wind potential in the 10 windiest U.S. states would not only provide more than enough energy to displace emissions from the nation's coal-fired power plants but also eliminate the nation's major source of acid rain.
Ensure people’s health
Particulate matter is of growing concern because of its impacts on health. Its presence in the air along with other pollutants has contributed to make asthma one of the fastest growing childhood ailments in industrial and developing countries alike, and it has also recently been linked to lung cancer. Since wind energy is a kind of clean energy, it will help contain the spread of asthma and other respiratory diseases aggravated or caused by air pollution in the country.
Protect biological food chain
Toxic heavy metals accumulate in the environment and up the biological food chain. A number of states have banned or limited the eating of fish from fresh-water lakes because of concerns about mercury, a toxic heavy metal, accumulating in their tissue. By using wind energy, it is estimated that such conditions will reduce and the negative impacts of heavy metals will be controlled.
Economical
Saving money
As with every other study of non-economic costs that has been conducted, the Externe study found wind energy's costs to be among the lowest, far below those of fossil fuels. The highest non-economic cost for wind in any European country, for example, was 0.25 Euro cents per kilowatt-hour, while the lowest cost for coal was 2-4 Euro cents/kWh (eight to 16 times as much).
Saving living area
In open, flat terrain, a utility-scale wind plant will require about 60 acres per megawatt of installed capacity. However, only 5% (3 acres) or less of this area is actually occupied by turbines, access roads, and other equipment--95% remains free for other compatible uses such as farming or ranching.
Saving water
Water is very important in energy production, particularly in areas where water is scarce. This is because conventional power plants need large amounts of water for the condensing portion of the thermodynamic cycle. Different kinds of conventional power plants consume different amounts of water. Here is a diagram which shows the water consumption of some kinds of conventional power plants (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
related wbsites:
http://www.repp.org/repp_pubs/repp_publications.html
http://www.externe.info/externpr.pdf
(He Yeqi)
Public attitudes to wind energy
provided by: Yeqi :)It's more popular than you
might have been told!
Many people believe
that wind farms are noisy and can disturb the lives of locals. On the
contrary,
people who live near a wind farm and have direct experience of it
generating
electricity tend to be more positive than those who do not.
Indeed, recent
studies has shown that the closer people live to a wind farm
the more supportive
they are of both the project and wind power as an energy
source.
In fact,
wind energy is one of the most popular of the energy
technologies. Certainly if
you were to ask people which form of power
generation they would like to see
more of, the answer is least likely to be
nuclear, oil, coal or gas. More than
eight out of ten people are in favor of
wind energy and less than one in ten
against it. However, this 5% often have
the most to say and certainly say it the
loudest, which often creates the
impression that wind farms are very unpopular.
Monday, May 12, 2008
Minutes for discussion 1
23rd,April,2008
Discussion on our poster
In our SIA procedure, we are supposed to design our own poster which is able to reveal our main ideas about the topic(wind energy).
On 23rd,April,2008,we discussed on the contents of our poster. In the end, we decided our main points and theme of our slogan.
The main points of the poster should include physics principle of wind energy, energy conversion,the advantages of using wind energy(It is renewable, good for saving fossil fuel and doing no harm to our environment) as well as the lack of fossil fuel nowadays.
Also, the theme of our slogan is to arouse public awareness of protecting environment by using clean energy especially wind energy.
Finally, we arranged the time and venue to do our first draft. We decided to do it on Monday afternoon, Term 2,Week 10 outside Nanyang Girls' Boarding School. Meanwhile, we may consider how to bring out ideas in details.
Discussion on our poster
In our SIA procedure, we are supposed to design our own poster which is able to reveal our main ideas about the topic(wind energy).
On 23rd,April,2008,we discussed on the contents of our poster. In the end, we decided our main points and theme of our slogan.
The main points of the poster should include physics principle of wind energy, energy conversion,the advantages of using wind energy(It is renewable, good for saving fossil fuel and doing no harm to our environment) as well as the lack of fossil fuel nowadays.
Also, the theme of our slogan is to arouse public awareness of protecting environment by using clean energy especially wind energy.
Finally, we arranged the time and venue to do our first draft. We decided to do it on Monday afternoon, Term 2,Week 10 outside Nanyang Girls' Boarding School. Meanwhile, we may consider how to bring out ideas in details.
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