Environmental impact of wind power

Livestock ignore wind turbines,^[1] and continue to graze as they did before wind turbines were installed.

Compared to the environmental impact of traditional energy sources, the environmental impact of wind power is relatively minor. Wind power consumes no fuel, and emits no air pollution, unlike fossil fuel power sources. The energy consumed to manufacture and transport the materials used to build a wind power plant is equal to the new energy produced by the plant within a few months. While a wind farm may cover a large area of land, many land uses such as agriculture are compatible, with only small areas of turbine foundations and infrastructure made unavailable for use.^[2]

There are reports of bird and bat mortality at wind turbines as there are around other artificial structures. The scale of the ecological impact may^[3] or may not^[4] be significant, depending on specific circumstances. Prevention and mitigation of wildlife fatalities, and protection of peat bogs,^[5] affect the siting and operation of wind turbines.

There are anecdotal reports of negative effects from noise on people who live very close to wind turbines. Peer-reviewed research has generally not supported these statements.^[6][7]

Carbon dioxide emissions and pollution

Wind power consumes no fuel and no water^[8] for continuing operation, and has no emissions directly related to electricity production. Wind turbines produce no carbon dioxide, carbon monoxide, sulfur dioxide, nitrogen dioxide, mercury, radioactive waste, particulates, or any other type of air pollution, unlike fossil fuel power sources. Wind power plants consume resources in manufacturing and construction. During manufacture of the wind turbine, steel, concrete, aluminium and other materials will have to be made and transported using energy-intensive processes, generally using fossil energy sources. The wind turbine manufacturer Vestas states that initial carbon dioxide emissions "pay back" is within about 9 months of operation for off shore turbines.^[9]

A 2006 study found the CO₂ emissions of wind power to range from 14 to 33 tonnes (15 to 36 short tons) per GWh of energy produced. Most of the CO₂ emission comes from producing the concrete for wind-turbine foundations.^[10]

A study by the Irish national grid stated that "Producing electricity from wind reduces the consumption of fossil fuels and therefore leads to emissions savings", and found reductions in CO₂ emissions ranging from 0.33 to 0.59 tonne (0.36 to 0.65 short ton) of CO₂ per MWh.^[11]

The UK Energy Research Centre (UKERC) study of intermittency also states that wind energy can displace fossil fuel-based generation, reducing both fuel use and carbon dioxide emissions. ^[12]

The production of permanent magnets used in some wind turbines makes use of neodymium.^[13][14] Primarily exported by China, pollution concerns associated with the extraction of this rare-earth element have prompted government action in recent years,^[15][16] and international research attempts to refine the extraction process.^[17] Research is underway on turbine and generator designs which reduce the need for neodymium, or eliminate the use of rare-earth metals altogether.^[18] However, Enercon did choose very early not to use permanent magnets for its direct drive turbines, in order to avoid responsibility in the bad environmental imprint of rare earth mining.^[19]

Net energy gain

The initial carbon dioxide emission from energy used in the installation is "paid back" within about 9 months of operation for off shore turbines. Any practical large-scale energy source must replace the energy used in its construction. The energy return on investment (EROI) for wind energy is equal to the cumulative electricity generated divided by the cumulative primary energy required to build and maintain a turbine. The EROI for wind ranges from 5 to 35, with an average of around 18, according to wind-energy advocates. EROI is strongly proportional to turbine size,^[20] and larger late-generation turbines are at the high end of this range, at or above 35.^[9] Since energy produced is several times energy consumed in construction, there is a net energy gain.^[2]

Ecology

Land use

Wind farm near an open-pit coal mine in Germany. Wind farms are often built on or near land that has already been impacted by land clearing.

impact lowering and yield enhancing choice: 11x 7,5MW instead of 23x 2MW-class wind turbines for the same area, Estinnes Belgium October 2010

In the United States, landowners typically receive $3,000 to $5,000 per year in rental income from each wind turbine, while farmers continue to grow crops or graze cattle up to the foot of the turbines.^[21]

A wind turbine at Greenpark, Reading, England, producing electricity for around one thousand homes

Wind farms are often built on land that has already been impacted by land clearing. The vegetation clearing and ground disturbance required for wind farms is minimal compared with coal mines and coal-fired power stations. If wind farms are decommissioned, the landscape can be returned to its previous condition,^[22] although the concrete foundations will be left in place and access tracks may also be retained.

Farmers and graziers often lease land to companies building wind farms. In the U.S., farmers may receive annual lease payments of two thousand to five thousand dollars per turbine,^[23] and wind farms may also provide additional community payments "...to reward residents who have made no financial gains [directly] from wind energy development, but whose views of... [the] landscape now include a panorama of turbines".^[24]

The land can still be used for farming and cattle grazing. Livestock are unaffected by the presence of wind farms. International experience shows that livestock will "graze right up to the base of wind turbines and often use them as rubbing posts or for shade".^[22]

Wind-energy advocates contend that less than 1% of the land would be used for foundations and access roads, the other 99% could still be used for farming.^[25] Critics point out that the clearing of trees around tower bases may be necessary for installation sites on mountain ridges, such as in the northeastern U.S.^[26]

Turbines are not generally installed in urban areas. Buildings interfere with wind, turbines must be sited a safe distance ("setback") from residences in case of failure, and the value of land is high. There are a few notable exceptions to this. Toronto Hydro has built a lake shore demonstration project, and Steel Winds is a 20 MW urban project south of Buffalo, New York. Both of these projects are in urban locations, but benefit from being on uninhabited lake shore property.

In the UK there has also been concern about the damage caused to peat bogs,^[5][27] with one Scottish MEP campaigning for a moratorium on wind developments on peatlands saying that "Damaging the peat causes the release of more carbon dioxide than wind farms save".^[28]

Offshore locations use no land and avoid shipping channels.

Impact on wildlife

Environmental assessments are routinely carried out for wind farm proposals, and potential impacts on the local environment (e.g. plants, animals, soils) are evaluated.^[22] Turbine locations and operations are often modified as part of the approval process to avoid or minimise impacts on threatened species and their habitats. Any unavoidable impacts can be offset with conservation improvements of similar ecosystems which are unaffected by the proposal.^[22]

Projects such as the Black Law Wind Farm have received wide recognition for its contribution to environmental objectives, including praise from the Royal Society for the Protection of Birds, who describe the scheme as both improving the landscape of a derelict opencast mining site and also benefiting a range of wildlife in the area, with an extensive habitat management projects covering over 14 square kilometres.^[29]

A research agenda from a coalition of researchers from universities, industry, and government, supported by the Atkinson Center for a Sustainable Future, suggests modeling the spatiotemporal patterns of migratory and residential wildlife with respect to geographic features and weather, to provide a basis for science-based decisions about where to site new wind projects. More specifically, it suggests:

• Use existing data on migratory and other movements of wildlife to develop predictive models of risk.
• Use new and emerging technologies, including radar, acoustics, and thermal imaging, to fill gaps in knowledge of wildlife movements.
• Identify specific species or sets of species most at risk in areas of high potential wind resoures. ^[30]

Birds

A Red Kite killed at a wind farm in Germany

A study^[31] estimates that wind farms are responsible for 0.3 to 0.4 fatalities per gigawatt-hour (GWh) of electricity while fossil-fueled power stations are responsible for about 5.2 fatalities per GWh. The study therefore states that fossil fuel based electricity causes about 10 times more fatalities than wind farm based electricity, primarily due to habitat alteration from pollution and mountain-top removal for coal mining. In Denmark, where wind turbines generate 9% of electricity, wind turbines kill about 30,000 birds per year.^[32] In the United States, the U.S. Fish and Wildlife Service estimated in 2009, that turbines kill 440,000 birds per year, though mortality is expected to increase significantly as wind power generation expands by 2030 to levels about 12 times higher than 2009 levels. In comparison, 80,000 birds are killed by aircraft,^[33] and 500 million killed by cats every year. Even greater numbers of bird deaths are attributed to collisions with buildings.^[33][34] Other studies have stated that 57 million are killed by cars, 97.5 million killed by collisions with plate glass,^[35] and hundreds of millions killed by cats.^[36] An article in Nature stated that each wind turbine kills an average of 4.27 birds per year.^[37]

In the UK, the Royal Society for the Protection of Birds (RSPB) concluded that "The available evidence suggests that appropriately positioned wind farms do not pose a significant hazard for birds."^[4] It notes that climate change poses a much more significant threat to wildlife, and therefore supports wind farms and other forms of renewable energy. In 2009 the RSPB warned that "numbers of several breeding birds of high conservation concern are reduced close to wind turbines," probably because "birds may use areas close to the turbines less often than would be expected, potentially reducing the carrying capacity of an area."^[38] The National Audubon Society in the U.S. takes a similar position, broadly supporting wind power to help mitigate global warming, while cautioning against siting wind farms in areas especially important to birds and other affected wildlife.^[39]

Concerns have been expressed that wind turbines at Smøla in Norway are having a deleterious effect on the population of White-tailed Eagles, Europe's largest bird of prey. They have been the subject of an extensive re-introduction programme in Scotland, which could be jeopardised by the expansion of wind turbines.^[40]

The Peñascal Wind Power Project in Texas is located in the middle of a major bird migration route, and the wind farm uses avian radar originally developed for NASA and the United States Air Force to detect birds as far as four miles away. If the system determines that the birds are in danger of running into the rotating blades, it shuts down the turbines. The system automatically restarts the turbines when the birds have passed.^[41]

At the Altamont Pass Wind Farm in California, a settlement has been reached between the Audubon Society, Californians for Renewable Energy and NextEra Energy Resources (who operate some 5,000 turbines in the area). Nearly half of the smaller turbines will be replaced by newer, more bird-friendly models. The project is expected to be complete by 2015 and includes $2.5 million for raptor habitat restoration.^[42]

Some paths of bird migration, particularly for birds that fly by night, are unknown. A study suggests that migrating birds may avoid the large turbines,^[43] at least in the low-wind non-twilight conditions studied. A Danish 2005 (Biology Letters 2005:336) study showed that radio tagged migrating birds traveled around offshore wind farms. Less than 1% of migrating birds passing an offshore wind farm in Rønde, Denmark, got close to collision, though the site was studied only during low-wind non-twilight conditions.

Bats

A Savi's Pipistrelle bat killed at the Ravna 1 Wind Farm on Pag Island, Croatia^[44]

Bats may be injured by direct impact with turbine blades, towers, or transmission lines. Recent research shows that bats may also be killed when suddenly passing through a low air pressure region surrounding the turbine blade tips.^[45]

The numbers of bats killed by existing onshore and near-shore facilities has troubled bat enthusiasts.^[46] A study in 2004 estimated that over 2,200 bats were killed by 63 onshore turbines in just six weeks at two sites in the eastern U.S.^[47] This study suggests some onshore and near-shore sites may be particularly hazardous to local bat populations and more research is needed. Migratory bat species appear to be particularly at risk, especially during key movement periods (spring and more importantly in fall). Lasiurines such as the hoary bat, red bat^{[disambiguation needed ]}, and the silver-haired bat appear to be most vulnerable at North American sites. Almost nothing is known about current populations of these species and the impact on bat numbers as a result of mortality at windpower locations. It has been suggested that bats are attracted to these structures in search of roosts.^[48] Offshore wind sites 10 km (6 mi) or more from shore do not interact with bat populations.^{[citation needed]}

Scientists at the U.S. Geological Survey have already conducted research using stable isotope analysis to track migration among terrestrial mammals. USGS scientists are currently applying this technique in their efforts to figure out the geographic origins of bats killed by wind turbines.^[49]

In April 2009 the Bats and Wind Energy Cooperative released initial study results showing a 73% drop in bat fatalities when wind farm operations are stopped during low wind conditions, when bats are most active.^[50]

Bats avoid radar transmitters, and placing microwave transmitters on wind turbine towers may reduce the number of bat collisions.^[51][52]

Climate change

Wind farms may affect weather in their immediate vicinity. Spinning wind turbine rotors generate a lot of turbulence in their wakes like the wake of a boat. This turbulence increases vertical mixing of heat and water vapor that affects the meteorological conditions downwind. The first study to demonstrate impacts of wind farms on weather and climate used a regional climate model. Data from an operational wind farm in Palm Springs, California, confirmed the model results. Overall, wind farms lead to a warming at night and cooling during the day time. This effect can be reduced by using more efficient rotors or placing wind farms in regions with high natural turbulence. Somnath Baidya Roy, the author of the study suggested that the warming at night could "benefit agriculture by decreasing frost damage and extending the growing season. Many farmers already do this with air circulators".^[53][54][55]

A number of studies have used climate models to study the effect of extremely large wind farms. One study reports simulations that show detectable changes in global climate for very high wind farm usage, on the order of 10% of the world's land area. Wind power has a negligible effect on global mean surface temperature, and it would deliver "enormous global benefits by reducing emissions of CO2 and air pollutants".^[56] Another study published in Atmospheric Chemistry and Physics suggested that using wind turbines to meet 10 percent of global energy demand in 2100 could actually have a warming effect, causing temperatures to rise by 1 °C (1.80 °F) in the regions on land where the wind farms are installed, including a smaller increase in areas beyond those regions. This is due to the effect of wind turbines on both horizontal and vertical atmospheric circulation. Whilst turbines installed in water would have a cooling effect, the net impact on global surface temperatures would be an increase of 0.15 °C (0.270 °F). Author Ron Prinn cautioned against interpreting the study "as an argument against wind power, urging that it be used to guide future research". "We’re not pessimistic about wind," he said. "We haven’t absolutely proven this effect, and we’d rather see that people do further research".^[57]

Hazardous waste

In 2011, a Minnesota wind-turbine blade manufacturing plant was fined $490,000 for air quality, hazardous waste, and stormwater violations.^[58]

Impacts on people

See also: Renewable energy debate#Community debate about wind farms

Safety

Operation of any utility-scale energy conversion system presents safety hazards. Wind turbines do not consume fuel or produce pollution during normal operation, but still have hazards associated with their construction, operation and maintenance.

With the installation of industrial sized wind turbines numbering in the thousands, there have been at least 40 fatalities of workers due to the construction, operation, and maintenance of wind turbines, and other injuries and deaths attributed to the wind power life cycle.^[59][60][61] Most worker deaths involve falls or becoming caught in machinery while performing maintenance inside turbine housings.

If a turbine's brake fails, the turbine can spin freely until it disintegrates or catches fire. Often turbine fires cannot be extinguished because of the height, and are left to burn themselves out. In the process, they generate toxic fumes and can scatter flaming debris over a wide area, starting secondary fires below. Several turbine-ignited fires have burned hundreds of acres of vegetation each, and one burned 800 square kilometres (200,000 acres) of Australian National Park.^{[59][62][63][64][not in citation given]}

During winter ice may form on turbine blades and subsequently be thrown off during operation. This is a potential safety hazard,^[65] and has led to localised shut-downs of turbines.^[66]. Modern turbines can detect ice formation, and shut down.

Electronic controllers and safety sub-systems monitor many different aspects of the turbine, generator, tower, and environment to determine if the turbine is operating in a safe manner within prescribed limits. These systems can temporarily shut down the turbine due to high wind, ice, electrical load imbalance, vibration, and other problems. Recurring or significant problems cause a system lockout and notify an engineer for inspection and repair. In addition, most systems include multiple passive safety systems that stop operation even if the electronic controller fails.

In his book Wind Energy Comes of Age, Paul Gipe estimated that the mortality rate for wind power from 1980–1994 was 0.4 deaths per terawatt-hour.^[67][68] Paul Gipe's estimate as of end 2000 was 0.15 deaths per TWh, a decline attributed to greater total cumulative generation.

Aesthetics

Newer wind farms have larger, more widely spaced turbines, and have a less cluttered appearance than older installations. Wind farms are often built on land that has already been impacted by land clearing and they coexist easily with other land uses (e.g. grazing, crops). They have a smaller footprint than other forms of energy generation such as coal and gas plants.^[69] Wind farms may be close to scenic or otherwise undeveloped areas, and aesthetic issues are important for onshore and near-shore locations.

Aesthetic issues are subjective and some people find wind farms pleasant and optimistic, or symbols of energy independence and local prosperity.^[70] While some tourism officials predict wind farms will damage tourism,^[71] some wind farms have themselves become tourist attractions,^[72][73][74] with several having visitor centers at ground level or even observation decks atop turbine towers.

Residents near turbines may complain of "shadow flicker" on nearby residences caused by rotating turbine blades, when the sun passes behind the turbine. This can easily be avoided by locating the wind farm to avoid unacceptable shadow flicker, or by turning the turbine off for the few minutes of the day when the sun is at the angle that causes flicker.^[69]

Wind towers require aircraft warning lights, which may create light pollution. Complaints about these lights have caused the FAA to consider allowing fewer lights per turbine in certain areas.^[75]

Noise

Modern wind turbines produce significantly less noise than older designs. Turbine designers work to minimise noise, as noise reflects lost energy and output. Noise levels at nearby residences may be managed through the siting of turbines, the approvals process for wind farms, and operational management of the wind farm.^[76]

Renewable UK, a wind energy trade organization, has said that the noise measured 305 metres (1,000 ft) from a wind farm is less than that from normal road traffic or in an office;^[77] some physicians and acoustic engineers have reported problems from wind turbine noise, including sleep deprivation, headaches, dizziness, anxiety, and vertigo.^[78][79][80]

Nina Pierpont, a New York pediatrician and wife of an anti-wind energy activist,^[81][82] states that noise can be an important disadvantage of wind turbines, especially when building the wind turbines very close to urban environments. The controversy around Pierpont's work centers around her statements made in a self-published, non-peer-reviewed book that ultra-low frequency sounds affect human health, which are based on a very small sample of self-selected subjects with no control group for comparison. She asserts that wind turbines affect the mood of people and may cause physiological problems such as insomnia, headaches, tinnitus, vertigo and nausea.^[83][84]

In December 2006, a Texas jury denied a noise pollution suit against FPL Energy, after the company demonstrated that noise readings were not excessive. The highest reading was 44 decibels, which was characterized as about the same level as a 10 miles per hour (16 km/h) wind.^{[citation needed]} The nearest residence among the plaintiffs was 1,700 feet (520 m) from one of the turbines.^[85] More recent lawsuits have been brought in Missouri,^[86] Pennsylvania,^[87] and Maine.^[88]

In the Canadian Province of Ontario, the Ministry of the Environment created noise guidelines to limit wind turbine noise levels 30 metres away from a dwelling or campsite to 40 dB(A).^[89] These regulations also set a minimum distance of 550 metres (1,800 ft) for a group of up to five relatively quiet [102 dB(A)] turbines within a 3-kilometre (1.9 mi) radius, rising to 1,500 metres (4,900 ft) for a group of 11 to 25 noisier (106-107 dB(A)) turbines. Larger facilities and noisier turbines would require a noise study.^[90][91][6]

In a 2009 report about "Rural Wind Farms", a Standing Committee of the Parliament of New South Wales, Australia, recommended a minimum setback of two kilometres between wind turbines and neighbouring houses (which can be waived by the affected neighbour) as a precautionary approach.^[92] In July 2010, Australia's National Health and Medical Research Council reported that "there is no published scientific evidence to support adverse effects of wind turbines on health".^[93]

A 2008 guest editorial in Environmental Health Perspectives published by the National Institute of Environmental Health Sciences, the U.S. National Institutes of Health, stated: "Even seemingly clean sources of energy can have implications on human health. Wind energy will undoubtedly create noise, which increases stress, which in turn increases the risk of cardiovascular disease and cancer."^[94]

The Japanese Environment Ministry will begin a "major study into the influence of sounds of wind turbines on people's health" in April 2010, because "people living near wind power facilities are increasingly complaining of health problems". They plan a four-year examination of all 1,517 wind turbines in the country.^[95]

A 2007 report by the U.S. National Research Council noted that noise produced by wind turbines is generally not a major concern for humans beyond a half-mile or so. Low-frequency vibration and its effects on humans are not well understood and sensitivity to such vibration resulting from wind-turbine noise is highly variable among humans. There are opposing views on this subject, and more research needs to be done on the effects of low-frequency noise on humans.^[96]

Research by Stefan Oerlemans for the University of Twente and the Dutch National Aerospace Laboratory suggests that noise from existing wind turbines may be reducible by up to half by adding "saw teeth" to the trailing edges of the blades, although research is not complete.^[97]

2009 review

A 2009 expert panel review, described as being the most comprehensive to date, delved into the possible adverse health effects of those living close to wind turbines. Their report findings concluded that wind turbines do not directly make people ill.^[6][7]

The 85-page study was sponsored by the Canadian Wind Energy Association and American Wind Energy Association. The academic and medical experts who conducted the study stated that they reached their conclusions independent of their sponsors. "We were not told to find anything," said panel expert David Colby, a public health officer in Chatham-Kent and a Professor of Medicine at the University of Western Ontario. "It was completely open ended."^[6]

The study did allow that some people could experience stress or irritation caused by the swishing sounds wind turbines produce. "A small minority of those exposed report annoyance and stress associated with noise perception..." [however] "Annoyance is not a disease." The study group pointed out that similar irritations are produced by local and highway vehicles, as well as from industrial operations and aircraft.^[6]

The report found, amongst other things, that:^[6]

• "Wind Turbine Syndrome" symptoms are the same as those seen in the general population due to stresses of daily life. They include headaches, insomnia, anxiety, dizziness, etc...^[6]
• low frequency and very low-frequency "infrasound" produced by wind turbines are the same as those produced by vehicular traffic and home appliances, even by the beating of people's hearts. Such 'infrasounds' are not special and convey no risk factors;^[6]
• Colby stated that evidence of harm was so minuscule that the wind associations were unable to initiate other independent collinear studies by government agencies. It was not surprising that their requests met with complete blanks on the need to examine the issues further;^[6]
• one study member noted: "You can't control the amount of cars going by and wind turbine noise is generally quieter than highway noise";^[6]
• the power of suggestion, as conveyed by news media coverage of perceived 'wind-turbine sickness', might have triggered "anticipatory fear" in those close to turbine installations.^[6]

The study panel members included: Robert Dobie, a doctor and clinical professor at the University of Texas, Geoff Leventhall, a noise vibration and acoustics expert in the United Kingdom, Bo Sondergaard, with Danish Electronics Light and Acoustics, Michael Seilo, a professor of audiology at Western Washington University, and Robert McCunney, a biological engineering scientist at the Massachusetts Institute of Technology. McCunney contested statements that infrasounds from wind turbines could create vibrations causing ill health: "It doesn't really have much credence, at least based on the literature out there" he stated.^[6]

Offshore

Many offshore wind farms are being built in UK waters. In January 2009, a comprehensive government environmental study of coastal waters in the United Kingdom concluded that there is scope for between 5,000 and 7,000 offshore wind turbines to be installed without an adverse impact on the marine environment. The study – which forms part of the Department of Energy and Climate Change's Offshore Energy Strategic Environmental Assessment – is based on more than a year's research. It included analysis of seabed geology, as well as surveys of sea birds and marine mammals.^[98][99]

See also

• Environmental movement
• Environmental concerns with electricity generation
• Environmental effects of coal
• Environmental effects of nuclear power
• Environmental issues with energy
• Renewable energy debate

References

1. ^ Buller, Erin (2008-07-11). "Capturing the wind". Uinta County Herald. http://www.uintacountyherald.com/V2_news_articles.php?heading=0&page=72&story_id=1299. Retrieved 2008-12-04. "The animals don’t care at all. We find cows and antelope napping in the shade of the turbines." - Mike Cadieux, site manager, Wyoming Wind Farm
2. ^ ^{a b} Why Australia needs wind power
3. ^ Eilperin, Juliet; Steven Mufson (16 April 2009). "Renewable Energy's Environmental Paradox". The Washington Post. http://www.washingtonpost.com/wp-dyn/content/article/2009/04/15/AR2009041503622_2.html?hpid=topnews&sid=ST2009041602328. Retrieved 2009-04-17. 
4. ^ ^{a b} "Wind farms". Royal Society for the Protection of Birds. 2005-09-14. http://www.rspb.org.uk/ourwork/policy/windfarms/index.asp. Retrieved 2008-09-07. 
5. ^ ^{a b} Lindsay, Richard (October 2004). WIND FARMS AND BLANKET PEAT The Bog Slide of 16 October 2003 at Derrybrien, Co. Galway, Ireland. The Derrybrien Development Cooperatve Ltd. http://www.uel.ac.uk/erg/documents/Derrybrien.pdf. Retrieved 20 May 2009. 
6. ^ ^{a b c d e f g h i j k l} Hamilton, Tyler (15 December 2009). "Wind Gets Clean Bill of Health: Turbines Do Not Make People Sick, Industry-Funded Study of Impacts Concludes". TorontoStar.com (Toronto, Canada: Toronto Star): pp. B1–B2. http://www.thestar.com/business/article/738734--wind-gets-clean-bill-of-health. Retrieved 16 December 2009. 
7. ^ ^{a b} W. David Colby, Robert Dobie, Geoff Leventhall, David M. Lipscomb, Robert J. McCunney, Michael T. Seilo, Bo Søndergaard. "Wind Turbine Sound and Health Effects: An Expert Panel Review", Canadian Wind Energy Association, December 2009.
8. ^ Mielke, Erik. Water Consumption of Energy Resource Extraction, Processing, and Conversion Harvard Kennedy School, October 2010. Accessed: 1 February 2011.
9. ^ ^{a b} "Vestas: Life Cycle Assessments (LCA)". http://www.vestas.com/en/about-vestas/sustainability/wind-turbines-and-the-environment/life-cycle-assessment-(lca).aspx. Retrieved 2008-02-13. 
10. ^ http://www.springerlink.com/content/ug33477443j40vx4/
11. ^ "Impact of Wind Generation in Ireland on the Operation of Conventional Plant and the Economic Implications" (PDF). ESB National Grid. February 2004. Archived from the original on 2007-12-01. http://web.archive.org/web/20071201192030/http://www.eirgrid.com/EirGridPortal/uploads/Publications/Wind+Impact+Study+-+main+report.pdf. Retrieved 2008-01-15. 
12. ^ Gross, Robert; Heptonstall, Philip; Anderson, Dennis; Green, Tim; Leach, Matthew; Skea, Jim (March 2006). The Costs and Impacts of Intermittency. UK Energy Research Council. p. iii. ISBN 1 90314 404 3. http://www.ukerc.ac.uk/Downloads/PDF/06/0604Intermittency/0604IntermittencyReport.pdf. Retrieved 2010-07-27. "it is unambiguously the case that wind energy can displace fossil fuel-based generation, reducing both fuel use and carbon dioxide emissions" 
13. ^ Perry, Simon; Ed Douglas (29). "In China, the true cost of Britain's clean, green wind power experiment: Pollution on a disastrous scale". Daily Mail. http://www.dailymail.co.uk/home/moslive/article-1350811/In-China-true-cost-Britains-clean-green-wind-power-experiment-Pollution-disastrous-scale.html. Retrieved 2011-03-02. 
14. ^ Hilsum, Lindsey (6). "Chinese pay toxic price for a green world". The Sunday Times. http://www.timesonline.co.uk/tol/news/world/asia/article6946038.ece. Retrieved 2011-03-02. 
15. ^ Bradsher, Keith (26). "Earth-Friendly Elements Are Mined Destructively". The New York Times. http://www.nytimes.com/2009/12/26/business/global/26rare.html?_r=1&hp=&pagewanted=all. Retrieved 2011-03-02. 
16. ^ Biggs, Stuart (6). "Rare Earths Leave Toxic Trail to Toyota Prius, Vestas Turbines". Bloomberg L.P.. http://www.bloomberg.com/news/2011-01-05/china-rare-earths-leave-toxic-trail-to-toyota-prius-vestas-wind-turbines.html. Retrieved 2011-03-02. 
17. ^ Ingebretsen, Mark. Developing greener, cheaper magnets Ames Laboratory. Accessed: 10 March 2011.
18. ^ Biello, David (13). "Rare Earths: Elemental Needs of the Clean-Energy Economy". Scientific American. http://www.scientificamerican.com/article.cfm?id=rare-earths-elemental-needs-of-the-clean-energy-economy. Retrieved 2011-03-02. 
19. ^ Enercon explanation p.4 why to avoid Neodymium use
20. ^ Nate Hagens (19 October 2006). "Energy from Wind: A Discussion of the EROI Research". pp. Figure 2. http://www.theoildrum.com/story/2006/10/17/18478/085. Retrieved 2008-02-13. 
21. ^ American Wind Energy Association (2009). Annual Wind Industry Report, Year Ending 2008 pp. 9-10.
22. ^ ^{a b c d} New South Wales Government (1 November 2010). The wind energy fact sheet Department of Environment, Climate Change and Water, p. 13
23. ^ "RENEWABLE ENERGY — Wind Power’s Contribution to Electric Power Generation and Impact on Farms and Rural Communities (GAO-04-756)" (PDF). United States Government Accountability Office. September 2004. http://www.gao.gov/new.items/d04756.pdf. Retrieved 2006-04-21. 
24. ^ Van der Voo, Lee. Money Blows in to a Patch of Oregon Known for Its Unrelenting Winds, New York Times, 31 May 2011, pg.A16]. Published online at NYTimes.com on 30 May 2011.
25. ^ "Wind energy Frequently Asked Questions". British Wind Energy Association. http://www.bwea.com/ref/faq.html. Retrieved 2006-04-21. 
26. ^ Forest clearance for Meyersdale, Pa., wind power facility
27. ^ Anon (2 February 2007). "Wind farm may 'damage' island bog". BBC News (BBC). http://news.bbc.co.uk/1/hi/scotland/highlands_and_islands/6321413.stm. Retrieved 20 May 2009. 
28. ^ Stevenson, Tony Struan (20 may 2009). "Bid to ban peatland wind farms comes under attack". Sunday Herald (newsquest (sunday herald) limited). http://www.sundayherald.com/news/heraldnews/display.var.2381294.0.bid_to_ban_peatland_wind_farms_comes_under_attack.php. Retrieved 20 may 2009. 
29. ^ UK's most powerful wind farm could power Paisley
30. ^ Zehnder and Warhaft, Alan and Zellman. "University Collaboration on Wind Energy". Cornell University. http://www.sustainablefuture.cornell.edu/attachments/2011-UnivWindCollaboration.pdf. Retrieved 17 August 2011. 
31. ^ Sovacool, B. K. (2009). "Contextualizing avian mortality: A preliminary appraisal of bird and bat fatalities from wind, fossil-fuel, and nuclear electricity". Energy Policy 37 (6): 2241–2248. doi:10.1016/j.enpol.2009.02.011.  edit
32. ^ "Sustainable Energy Without the Hot Air". UIT Cambridge Ltd.. 2008-09-14. http://www.inference.phy.cam.ac.uk/withouthotair/c10/page_64.shtml. Retrieved 2010-11-08. 
33. ^ ^{a b} Ruane, Laura (2008-11-06). "Newest Air Defense: Bird Dogs". USA Today. http://www.usatoday.com/news/offbeat/2008-11-06-birddogs_N.htm. Retrieved 2008-11-07. 
34. ^ Balogh, Anne L. & Ryder, Thomas B. & Marra, Peter P. "Population demography of Gray Catbirds in the Suburban Matrix: Sources, Sinks and Domestic Cats", Journal of Ornithology, 2011, DOI 10.1007/s10336-011-0648-7
35. ^ Lomborg, Bjørn (2001). The Skeptical Environmentalist. New York City: Cambridge University Press. 
36. ^ "Cats Indoors! The American Bird Conservancy's Campaign for Safer Birds and Cats". National Audubon Society. http://www.audubon.org/bird/cat/. Retrieved 2011-07-08. 
37. ^ Emma Marris; Daemon Fairless (10 May 2007). "Wind farms' deadly reputation hard to shift". Nature. pp. 447 126. doi:10.1038/447126a. http://www.nature.com/nature/journal/v447/n7141/full/447126a.html. Retrieved 2008-01-15.  Subscription required.
38. ^ "Upland birds face displacement threat from poorly sited wind turbines". Royal Society for the Protection of Birds. 2009-09-26. http://www.rspb.org.uk/media/releases/details.asp?id=tcm:9-230416. Retrieved 2009-09-30. 
39. ^ "Audubon's Position on Wind Power". National Audubon Society. http://www.audubon.org/campaign/windPowerQA.html. Retrieved 2008-09-05. ^{[dead link]}
40. ^ Wind farms condemned as eagles fall prey to turbines
41. ^ Matthew McDermott. "Texas Wind Farm Uses NASA Radar to Prevent Bird Deaths" Treehugger. Retrieved 2 May 2009.
42. ^ Andrew Dalton (7 December 2010). Altamont Pass to Get Less-Deadly Wind Turbines sfist.
43. ^ "Wind turbines a breeze for migrating birds". New Scientist (2504): 21. 18 June 2005. http://www.newscientist.com/channel/life/mg18625045.500. Retrieved 2006-04-21. 
44. ^ M.Zagmajster, T.Jančar & J.Mlakar (2007): First records of dead bats (Chiroptera) from wind farms in Croatia. Nyctalus 12(2-3): 234-237
45. ^ Baerwald, Erin F; D'Amours, Genevieve H; Klug, Brandon J; Barclay, Robert MR (2008-08-26). "Barotrauma is a significant cause of bat fatalities at wind turbines". Current Biology 18 (16): R695–R696. doi:10.1016/j.cub.2008.06.029. OCLC 252616082. PMID 18727900. Lay summary – CBC Radio - Quirks & Quarks (2008-09-20).  Laysource includes audio podcast of interview with author.
46. ^ "Caution Regarding Placement of Wind Turbines on Wooded Ridge Tops" (PDF). Bat Conservation International. 4 January 2005. http://vawind.org/Assets/Docs/BCI_ridgetop_advisory.pdf. Retrieved 2006-04-21. 
47. ^ Arnett, Edward B.; Wallace P. Erickson, Jessica Kerns, Jason Horn (June 2005). "Relationships between Bats and Wind Turbines in Pennsylvania and West Virginia: An Assessment of Fatality Search Protocols, Patterns of Fatality, and Behavioral Interactions with Wind Turbines" (PDF). Bat Conservation International. Archived from the original on 2006-02-10. http://web.archive.org/web/20060210183113/http://batcon.org/wind/BWEC2004finalreport.pdf. Retrieved 2006-04-21. 
48. ^ "Bats take a battering at wind farms", New Scientist, 12 May 2007
49. ^ "Bat Fatalities at Wind Turbines: Investigating the Causes and Consequences". US Geological Survey. http://www.fort.usgs.gov/batswindmills/. Retrieved 2010-06-29. 
50. ^ "Effectiveness of Changing Wind Turbine Cut-in Speed to Reduce Bat Fatalities at Wind Facilities" (PDF). American Wind Energy Association. 2009-04-28. http://www.batsandwind.org/pdf/Curtailment_2008_Final_Report.pdf. Retrieved 2009-04-28. 
51. ^ Aron, Jacob (2009-07-17). "Radar beams could protect bats from wind turbines". London: The Guardian. http://www.guardian.co.uk/environment/2009/jul/17/radar-bat-wind-turbine. Retrieved 2009-07-17. 
52. ^ Nicholls, Barry; Racey, Paul A. (2007). "Bats Avoid Radar Installations: Could Electromagnetic Fields Deter Bats from Colliding with Wind Turbines?". PLoS ONE 2 (3): e297. Bibcode 2007PLoSO...2..297N. doi:10.1371/journal.pone.0000297. PMC 1808427. PMID 17372629. http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0000297. Lay summary – The Guardian (2009-07-17). 
53. ^ Turbines and turbulence
54. ^ Proceedings of the National Academy of Sciences: Impacts of wind farms on surface air temperatures
55. ^ Wind farms impacting weather - Science Daily
56. ^ The influence of large-scale wind power on global climate — PNAS
57. ^ http://web.mit.edu/newsoffice/2010/climate-wind-0312.html MIT analysis suggests generating electricity from large-scale wind farms could influence climate — and not necessarily in the desired way.
58. ^ Pipestone wind-turbine blade maker hit with hefty penalty, twincities.com, August 4, 2011
59. ^ ^{a b} Craig, David (2007-11-30). "Summary of Wind Turbine Accident data". Caithness Windfarm Information Forum. http://www.caithnesswindfarms.co.uk/page4.htm. Retrieved 2007-12-30.  - Table of accidents, PDF format (anti-wind power)
60. ^ Gipe, Paul (2007). "A Summary of Fatal Accidents in Wind Energy". Wind-Works.org. http://www.wind-works.org/articles/ASummaryofFatalAccidentsinWindEnergy.html. Retrieved 2007-12-30. 
61. ^ Gipe, Paul (2006). "Contemporary Mortality (Death) Rates in Wind Energy". Wind-Works.org. http://www.wind-works.org/articles/BreathLife.html. Retrieved 2007-12-30.  - Table of fatalities, Microsoft Excel format (pro-wind power)
62. ^ "Wind Turbine Accidents Database" (in (German)). 2007-11-26. http://members.aol.com/fswemedien/ZZUnfalldatei.htm. Retrieved 2007-12-31. 
63. ^ "Experts try to determine wind farm blaze cause". ABC South East SA. 2006-01-23. http://www.abc.net.au/news/items/200601/1553257.htm?southeastsa. Retrieved 2007-12-31. 
64. ^ "Edenhope and Ngarkat fires". Naracoorte Herald. 2005. Archived from the original on 2008-01-07. http://web.archive.org/web/20080107103427/http://www.naracoorteherald.com.au/news.html. Retrieved 2007-12-31. 
65. ^ http://web1.msue.msu.edu/cdnr/icethrowseifertb.pdf
66. ^ http://www.telegraph.co.uk/news/uknews/3547074/Wind-turbine-closed-after-showering-homes-with-blocks-of-ice.html
67. ^ Gipe, Paul (1995). Wind Energy Comes of Age. John Wiley and Sons. pp. 560. ISBN 047110924X. http://books.google.com/?id=8itBNxBL4igC&pg=PA368&dq=0.23+death+per+terawatt. "The total mortality rate, admittedly based on scanty data from a young technology, is 0.23 death per terawatt-hour." 
68. ^ Gipe, Paul (2006). "Contemporary Mortality (Death) Rates in Wind Energy". Wind-Works.org. http://www.wind-works.org/articles/BreathLife.html. Retrieved 2007-12-30. "I reported in Wind Energy comes of Age a mortality rate of 0.27 deaths per TWh. However ... in the mid-1990s the mortally rate was actually 0.4 per TWh." 
69. ^ ^{a b} New South Wales Government (1 November 2010). The wind energy fact sheet Department of Environment, Climate Change and Water, p. 12.
70. ^ Wind farms are not only beautiful, they're absolutely necessary
71. ^ "Tourism blow for windfarm". Sunday Mirror. 2003-05-30. http://findarticles.com/p/articles/mi_qn4161/is_20030330/ai_n12863242. Retrieved 2008-09-06. 
72. ^ Young, Kathryn (2007-08-03). "Canada wind farms blow away turbine tourists". Edmonton Journal. http://www.canada.com/edmontonjournal/news/business/story.html?id=63a5438a-ae99-4b76-9629-b7b59d238932. Retrieved 2008-09-06. 
73. ^ Zhou, Renjie; Yadan Wang (2007-08-14). "Residents of Inner Mongolia Find New Hope in the Desert". Worldwatch Institute. http://www.worldwatch.org/node/5286. Retrieved 2008-11-04. 
74. ^ "Centre d'interprétation du cuivre de Murdochville". http://www.cicuivre.com/en/circuit.asp. Retrieved 2008-11-19.  - The Copper Interpretation Centre of Murdochville, Canada features tours of a wind turbine on Miller Mountain
75. ^ Rod Thompson (20 May 2006). "Wind turbine lights have opponents seeing sparks". Honolulu Star-Bulletin. http://starbulletin.com/2006/05/20/news/story06.html. Retrieved 2008-01-15. 
76. ^ New South Wales Government (1 November 2010). The wind energy fact sheet Department of Environment, Climate Change and Water, p. 8.
77. ^ "Noise from Wind Turbines - The Facts". RenewableUK. 2010. http://www.bwea.com/ref/noise.html. Retrieved 29 April 2010. 
78. ^ Keen, Judy (2008-11-03). "Neighbors at odds over noise from wind turbines". USA Today. http://www.usatoday.com/money/industries/energy/2008-11-03-windturbines_N.htm. 
79. ^ http://www.kselected.com/?page_id=6560
80. ^ http://www.mlive.com/news/bay-city/index.ssf/2009/06/wind_turbines_create_bad_buzz.html
81. ^ http://www.aweo.org/Martin.html
82. ^ http://www.aph.gov.au/Senate/committee/clac_ctte/impact_rural_wind_farms/submissions.htm
83. ^ Pierpont, Nina (7 March 2006). "Wind Turbine Syndrome: Testimony before the New York State Legislature Energy Committee". Save Western NY. http://www.savewesternny.org/docs/pierpont_testimony.html. Retrieved 29 April 2010. 
84. ^ Pagano, Margareta (Sunday, 2 August 2009). "Are wind farms a health risk? US scientist identifies 'wind turbine syndrome'". London: independent.co.uk. http://www.independent.co.uk/environment/green-living/are-wind-farms-a-health-risk-us-scientist-identifies-wind-turbine-syndrome-1766254.html. Retrieved 29 April 2010. 
85. ^ North American Windpower, May 2007. "Sound Defense For A Wind Turbine Farm".
86. ^ Associated Press, 3 February 2009. "NW Missouri man sues Deere, wind energy company".
87. ^ Phil Ray, Altoona Mirror, 27 March 2009. "Charges against wind companies upheld".
88. ^ Anne Ravana, Maine Public Broadcasting Network, 7 August 2009. "Discontent of Mars Hill residents leads to lawsuit against First Wind".
89. ^ Ministry of the Environment, Ontario (October 2008) "Noise Guidelines for Wind Farms"
90. ^ Ministry of the Environment, Ontario (9 June 2009). "Wind Turbines – Proposed Requirements and Setbacks"
91. ^ Government of Ontario (24 September 2009). "Ontario Makes It Easier, Faster To Grow Green Energy"
92. ^ General Purpose Standing Committee No. 5, Parliament of New South Wales (16 December 2009). "Final Report, Rural Wind Farms".
93. ^ National Health and Medical Research Council (July 2010). Wind Turbines and Health public statement.
94. ^ Julia M. Gohlke, Sharon H. Hrynkow, and Christopher J. Portier. "Health, Economy, and Environment: Sustainable Energy Choices for a Nation". Environ Health Perspect 2008 Jun;116(6):A236-7.
95. ^ Yomiuri Shimbun (29 November 2009). "Govt to study effects of wind farms on health".
96. ^ Committee on Environmental Impacts of Wind Energy Projects, National Research Council (2007). Environmental Impacts of Wind-Energy Projects, p. 158-9.
97. ^ "Saw teeth make wind turbines quieter". University of Twente. 3 September 2009. http://www.universiteittwente.nl/news/quieter-wind-turbines. Retrieved 29 April 2010. 
98. ^ Study finds offshore wind farms can co-exist with marine environment
99. ^ UK Offshore Energy Strategic Environmental Assessment