Environmental impact of wind power
The environmental impact of wind power for land-based wind turbines, compared to the environmental impacts of traditional energy sources, is relatively minor. It is slightly higher than the environmental impact of hydro power on a life-cycle basis. Unlike electricity derived from fossil fuel and nuclear power plants, wind power does not use fuel or employ a fueling cycle, thus emitting no air pollution or greenhouse gases.
While a wind farm may cover a large area of land, many land uses such as agriculture are compatible with it, as only small areas of turbine foundations and infrastructure are made unavailable for use.
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 or may not be significant, depending on specific circumstances. Prevention and mitigation of wildlife fatalities, and protection of peat bogs, affect the siting and operation of wind turbines.
- 1 Basic operational considerations
- 2 Ecology
- 3 Impacts on people
- 4 Offshore
- 5 See also
- 6 References
- 7 Further reading
- 8 External links
Basic operational considerations
Net energy gain
Modern wind turbine systems have a net energy gain, in other words during their service life they produce significantly more energy than is used to build the system. Any practical large-scale energy source must produce more energy than is 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. According to a meta study, in which all existing studies from 1977 to 2007 were reviewed, the EROI for wind ranges from 5 to 35, with an average of around 18. EROI is strongly proportional to turbine size, and larger late-generation turbines are at the high end of this range, at or above 35. Since energy produced is several times energy consumed in construction, there is a net energy gain.
Carbon dioxide emissions
Wind power consumes no fuel and no water 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 sources and nuclear power plant fuel production. Wind turbine manufacturer Vestas claims that initial energy "pay back" is within about 8.6 months of operation for a V80-2.0MW wind power plant under low wind conditions.
A 2006 study of 3 installations in the US Midwest found the CO
2 emissions of wind power ranged from 14 to 33 tonnes (15 to 36 short tons) per GWh of energy produced. Most of the CO
2 emission came from producing the concrete for wind-turbine foundations. 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 CO
2 emissions ranging from 0.33 to 0.59 tonnes (0.36 to 0.65 short ton) of CO
2 per MWh. The 2006 UK Energy Research Centre (UKERC) study focused on the intermittent nature of the output of some renewable energy sources, concluded that intermittency is not a major obstacle to the integration of renewable sources of electricity supply.
The production of permanent magnets used in some wind turbines makes use of neodymium. Primarily exported by China, pollution concerns associated with the extraction of this rare-earth element have prompted government action in recent years, and international research attempts to refine the extraction process. Research is underway on turbine and generator designs which reduce the need for neodymium, or eliminate the use of rare-earth metals altogether. Additionally, the large wind turbine manufacturer Enercon GmbH chose very early not to use permanent magnets for its direct drive turbines, in order to avoid responsibility for the adverse environmental impact of rare earth mining.
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.
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, 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".
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".
Wind-energy advocates contend that less than 1% of the land is used for foundations and access roads, the other 99% can still be used for farming. A wind turbine needs about 200–400 m² for the foundation. A (small) 500-kW-turbine with an annual production of 1.4 GWh produces 11.7 MWh/m², which is comparable with coal-fired plants (about 15-20 MWh/m²), coal-mining not included. With increasing size of the wind turbine the relative size of the fundation decreases. Critics point out that on some locations in forests the clearing of trees around tower bases may be necessary for installation sites on mountain ridges, such as in the northeastern U.S. This usually takes the clearing of 5,000 m² per wind turbine.
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. The WindShare ExPlace wind turbine was erected in December 2002, on the grounds of Exhibition Place, in Toronto, Canada. It was the first wind turbine installed in a major North American urban city centre. Steel Winds also has 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, 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".
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. 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.
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.
|Wind turbines||0.02 – 0.57||0.269|
|Nuclear power plants||0.33||0.416|
|Oilfield oil waste & waste water pits||0.50 – 1||(n/a)|
|Nuisance bird control kills (airports, agriculture, etc...)||2||(n/a)|
|Communication towers (cellular, radio, microwave)||4 – 50||(n/a)|
|Large communications towers (over 180', N. America)||6.8||(n/a)|
|Fossil fuel powerplants||14||5.18|
|Cars & trucks||50 – 100||(n/a)|
|Hunting||100 – 120||(n/a)|
|Transmission lines (conventional powerplants)||174 – 175||(n/a)|
|Buildings and windows||365 – 988||(n/a)|
|Domestic and feral cats||210 – 3,700||(n/a)|
The impact of wind energy on birds, which can fly into turbines directly, or indirectly have their habitats degraded by wind development, is complex. 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.
The meta-analysis on avian mortality by Benjamin K. Sovacool led him to suggest that there were a number of deficiencies in other researchers' methodologies. Among them, he stated were a focus on bird deaths, but not on the reductions in bird births: for example, mining activities for fossil fuels and pollution from fossil fuel plants have led to significant toxic deposits and acid rain that have damaged or poisoned many nesting and feeding grounds, leading to reductions in births. The large cumulated footprint of wind turbines, which reduces the area available to wildlife or agriculture, is also missing from all studies including Sovacool's. Many of the studies also made no mention of avian deaths per unit of electricity produced, which excluded meaningful comparisons between different energy sources. More importantly, it concluded, the most visible impacts of a technology, as measured by media exposure, are not necessarily the most flagrant ones.
The Sovacool study did a broad assessment of anthropogenic causes of avian mortality and brought together many studies on deaths due to wind energy, fossil fuel energy and nuclear energy. He estimated a figure for bird deaths due to wind power of 0.269 fatalities per gigawatt-hour (GWh), by which he extrapolated a total of 7193 US bird fatalities in 2006. He concluded that wind farms and nuclear power stations are responsible each for between 0.3 and 0.4 fatalities per gigawatt-hour (GWh) of electricity while fossil-fueled power stations are responsible for about 5.2 fatalities per GWh. Of the bird deaths Sovacool attributed to fossil-fuel power plants, 96 percent were due to the effects of climate change. While the study did not assess bat mortality due to various forms of energy, he considered it not unreasonable to assume a similar ratio of mortality. The Sovacool study has provoked controversy because of its treatment of data. In a series of replies, Sovacool acknowledged a number of large errors, particularly those that relate to a 0.4 fatalities overestimate for the number of bird deaths per GWh of nuclear power, and cautioned that "the study already tells you the numbers are very rough estimates that need to be improved."
Sovacool estimated that in the United States wind turbines kill between 20,000 and 573,000 birds per year, and although he states either figure is minimal compared to bird deaths from other causes. He uses the lower 20,000 figure in his study and table (see Causes of avian mortality table). Fossil-fueled power plants, which wind turbines generally require to make up for their weather dependent intermittency, kill almost 20 times as many birds per gigawatt hour (GWh) of electricity. Bird deaths due to other human activities and cats total between 797 million and 5.29 billion per year in the U.S. Additionally, while many studies concentrate on the analysis of bird deaths, few have been conducted on the reductions of bird births, which are the additional consequences of the various pollution sources that wind power partially mitigates.
A 2013 meta-analysis by Smallwood identified a number of factors which result in serious under-reporting of bird and bat deaths by wind turbines. These include inefficient searches, inadequate search radius, and carcass removal by predators. To adjust the results of different studies, he applied correction factors from hundreds of carcass placement trials. His meta-analysis concluded that in 2012 in the United States, wind turbines resulted in the deaths of 888,000 bats and 573,000 birds, including 83,000 raptors.
Also in 2013, a meta-analysis by Lossa and others in the journal Biological Conservation found that the likely mean number of birds killed annually in the U.S by wind turbines was 234,000. The authors acknowledged the larger number reported by Smallwood, but noted that Smallwood’s meta-analysis did not distinguish between types of wind turbine towers; older wind turbines were more often on lattice towers, which attract birds. The monopole towers used almost exclusively for new wind installations appear to result in fewer bird deaths.
Bird mortality at wind energy facilities can vary greatly depending on the facility's location, with some facilities reporting nearly zero bird fatalities, and others as high as four birds per turbine per year. An article in the journal Nature stated that each wind turbine in the U.S. kills an average of 0.03 birds per year, and recommends that more research needs to be done.
Wind facilities have attracted the most attention for impacts on iconic raptor species, including golden eagles. The Pine Tree Wind energy project near Tehachapi, California has one of the highest raptor mortality rates in the country; by 2012 at least eight golden eagles had been killed according to the U.S. Fish and Wildlife Service (USFWS). Biologists have noted that it is more important to avoid losses of large birds as they have lower breeding rates and can be more severely impacted by wind turbines in certain areas.
Large numbers of bird deaths are also attributed to collisions with buildings. An estimated 1 to 9 million birds are killed every year by tall buildings in Toronto, Canada alone, according to the wildlife conservation organization Fatal Light Awareness Program. Other studies have stated that 57 million are killed by cars, and some 365 to 988 million are killed by collisions with buildings and plate glass in the United States alone. Promotional event lightbeams as well as ceilometers used at airport weather offices can be particularly deadly for birds, as birds become caught in their lightbeams and suffer exhaustion and collisions with other birds. In the worst recorded ceilometer lightbeam kill-off during one night in 1954, approximately 50,000 birds from 53 different species died at the Warner Robins Air Force Base in the United States.
In the United Kingdom, 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." It notes that climate change poses a much more significant threat to wildlife, and therefore supports wind farms and other forms of renewable energy as a way to mitigate future damage. 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 wildlife carrying capacity of an area.
Concerns have been expressed that wind turbines at Smøla, 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.
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 4 miles (6.4 km) away. If the system determines that the birds are in danger of running into the rotating blades, the turbines shut down and are restarted when the birds have passed. A 2005 Danish study used surveillance radar to track migrating birds traveling around and through an offshore wind farm. Less than 1% of migrating birds passing through an offshore wind farm in Rønde, Denmark, got close enough to be at risk of collision, though the site was studied only during low-wind conditions. The study suggests that migrating birds may avoid large turbines, at least in the low-wind conditions the research was conducted in.
In 2012, researchers reported that, based on their four-year radar tracking study of birds after construction of an offshore wind farm near Lincolnshire, that pink-footed geese migrating to the U.K. to overwinter altered their flight path to avoid the turbines.
At the Altamont Pass Wind Farm in California, a settlement between the Audubon Society, Californians for Renewable Energy and NextEra Energy Resources who operate some 5,000 turbines in the area requires the latter to replace nearly half of the smaller turbines with newer, more bird-friendly models by 2015 and provide $2.5 million for raptor habitat restoration. The proposed Chokecherry and Sierra Madre Wind project in Wyoming, however, is expected to kill nearly 5,400 birds each year, including over 150 raptors, according to a Bureau of Land Management environmental analysis.
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.
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. Bats avoid radar transmitters, and placing microwave transmitters on wind turbine towers may reduce the number of bat collisions.
A 2013 study produced an estimate that wind turbines killed more than 600,000 bats in the U.S. the previous year, with the greatest mortality occurring in the Appalachian Mountains. Some earlier studies had produced estimates of between 33,000 and 888,000 bat deaths per year.
Weather and 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. Overall, wind farms lead to a slight warming at night and a slight 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. Warming at night could "benefit agriculture by decreasing frost damage and extending the growing season. Many farmers already do this with air circulators".
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 CO
2 and air pollutants". Another peer-reviewed study 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 (1.8 °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 (0.27 °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".
Impacts on people
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. 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. While some tourism officials predict wind farms will damage tourism, some wind farms have themselves become tourist attractions, 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 time of the day when the sun is at the angle that causes flicker. If a turbine is poorly sited and adjacent to many homes, the duration of shadow flicker on a neighborhood can last hours.
The location of a wind farm is critical to its overall power-generation. Each turbine depends on “micro-sitting,” or the exact position of the turbine, because a difference of 30 m can sometimes double a turbine’s output. Coastal and areas of higher altitude such as ridgelines are considered prime for wind farms, due to the constant wind speeds. Hills or ridges cause the wind to accelerate as it is forced over the higher altitude, increasing wind speed. A historical rule of thumb suggests that a site is not ideal for wind farm usage unless it exhibits average wind speeds of about 4.5 metres per second (10 mph) or higher. Both locations tend to be areas of high tourism and aesthetic value, causing many local communities to protest the development of wind farms. Coastal regions, however, tend to be highly populated, thus requiring more energy. While small wind farms can connect to the local electricity distribution grid, locating large wind farms in rural areas increases the cost and complexity of transferring generated power to population centers. Both the proximity to densely populated areas and the necessary wind speeds make coastal and ridgeline locations ideal for wind farms.
In 2011, Simon Chapman claimed in the Sydney Morning Herald that the British Acoustics Bulletin had published the 10th independent review of the evidence on wind farms causing annoyance and ill health in people. And for the 10th time it has emphasised that "annoyance has far more to do with social and psychological factors in those complaining than any direct effect from sound or inaudible infrasound emanating from wind turbines". Two factors repeatedly came up. "The first is being able to see wind turbines, which increases annoyance particularly in those who dislike or fear them. The second factor is whether people derive income from hosting turbines, which miraculously appears to be a highly effective antidote to feelings of annoyance and symptoms".
A 2009 expert panel review, sponsored by the Canadian Wind Energy Association and American Wind Energy Association, delved into the possible adverse health effects of those living close to wind turbines. Their 85-page report concluded that wind turbines do not directly make people ill. 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.
The 2009 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 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."
Eighteen research reviews about wind turbines and health, published since 2003, all showed that there was very little evidence that wind turbines were harmful in any direct way. Simon Chapman, professor of public health at Sydney University, said that if wind farms did genuinely make people ill there would by now be a large body of medical literature that would preclude putting them near populated areas. But this is not the case. Sickness being attributed to wind turbines is more likely to be caused by people getting alarmed at the health warnings circulated by activists. Complaints of illness were far more prevalent in communities targeted by anti-wind groups. Chapman's report concludes "that illnesses being blamed on windfarms are more than likely caused by the psychological effect of suggestions that the turbines make people ill, rather than by the turbines themselves".
Nina Pierpont, a New York pediatrician and wife of an anti-wind energy activist, 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. Simon Chapman has said that "wind turbine syndrome" is not recognised by any international disease classification system and does not appear in any title or abstract in the massive US National Library of Medicine's PubMed database. He says that the term appears to be spread by anti-wind farm activist groups. The 2009 expert panel review found that "wind turbine syndrome" symptoms are the same as those seen in the general population due to stresses of daily life, and include headaches, insomnia, anxiety, and dizziness.
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.
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. 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".
In Ontario, Canada, 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). 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.
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."
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.
Operation of any utility-scale energy conversion system presents safety hazards. If a turbine's brake and its control mechanisms fail, the turbine's rotor can overspin until it disintegrates or possibly catches fire. This is rare and the odds of a major turbine fire or disintegration is in the order of 0.001% over the 20-25 year lifespan of a modern wind turbine. Some turbine nacelle fires cannot be extinguished because of their height, and are sometimes left to burn themselves out. In such cases they generate toxic fumes and can cause secondary fires below. However, newer wind turbines are built with automatic fire extinguishing systems similar to those provided for jet aircraft engines. These autonomous systems, which can be retrofitted to older wind turbines, automatically detect a fire, order the shut down of the turbine unit and immediately extinguish the fires completely.
During winter ice may form on turbine blades and subsequently be thrown off during operation. This is a potential safety hazard, and has led to localised shut-downs of turbines. Modern turbines can detect ice formation and excess vibration during operations, and are shut down automatically. 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.
Many offshore wind farms have contributed to electricity needs in Europe and Asia for years, and as of 2014 the first offshore wind farms are under development in U.S. waters. While the offshore wind industry has grown dramatically over the last several decades, especially in Europe, there is still some uncertainty associated with how the construction and operation of these wind farms affect marine animals and the marine environment.
Traditional offshore wind turbines are attached to the seabed in shallower waters within the near-shore marine environment. As offshore wind technologies become more advanced, floating structures have begun to be used in deeper waters where more wind resources exist.
Common environmental concerns associated with offshore wind developments include:
- The risk to seabirds being struck by wind turbine blades or being displaced from critical habitats;
- Underwater noise associated with the installation process of monopile turbines;
- The physical presence of offshore wind farms altering the behavior of marine mammals, fish, and seabirds by reasons of either attraction or avoidance;
- Potential disruption of the near-field and far-field marine environments from large offshore wind projects.
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.
A study published in 2014 suggests that some seals prefer to hunt near turbines, likely due to the laid stones functioning as artificial reefs which attract invertebrates and fish.
- Environmental movement
- Environmental concerns with electricity generation
- Environmental effects of coal
- Environmental effects of nuclear power
- Environmental issues with energy
- Health effects from noise
- Renewable energy debate
- Buller, Erin (2008-07-11). "Capturing the wind". Uinta County Herald. 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"
- "Air Emissions". Retrieved 26 September 2013.
- Diesendorf, Mark. Why Australia Needs Wind Power, Dissent, Vol. No. 13, Summer 2003–04, pp. 43–48.
- "Wind energy Frequently Asked Questions". British Wind Energy Association. Retrieved 2006-04-21.
- Eilperin, Juliet; Steven Mufson (16 April 2009). "Renewable Energy's Environmental Paradox". The Washington Post. Retrieved 2009-04-17.
- "Wind farms". Royal Society for the Protection of Birds. 14 September 2005. Retrieved 6 December 2012.
- 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. Retrieved 20 May 2009.
- Gohlke JM et al. Environmental Health Perspectives (2008). "Health, Economy, and Environment: Sustainable Energy Choices for a Nation". Environmental Health Perspectives 116 (6): A236–A237. doi:10.1289/ehp.11602. PMC 2430245. PMID 18560493.
- Hamilton, Tyler (15 December 2009). "Wind Gets Clean Bill of Health". Toronto Star (Toronto). pp. B1–B2. Retrieved 16 December 2009.
- 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 (CanWEA), December 2009.
- Kubiszewski, Ida; C. J. Cleveland, and P. K. Endres. (1 January 2010). "Meta-Analysis of Net Energy Return for Wind Power Systems". Renewable Energy. 35 (1): 218–225. doi:10.1016/j.renene.2009.01.012.
- Mielke, Erik. Water Consumption of Energy Resource Extraction, Processing, and Conversion Harvard Kennedy School, October 2010. Accessed: 1 February 2011.
- "Vestas: Comparing energy payback". Retrieved 2013-05-05.
- White, S. W. (2007). "Net Energy Payback and CO2 Emissions from Three Midwestern Wind Farms: An Update". Natural Resources Research 15 (4): 271–281. doi:10.1007/s11053-007-9024-y.
- "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. Retrieved 2008-01-15.
- 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 1-903144-04-3. 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"
- Perry, Simon; Ed Douglas (29 January 2011). "In China, the true cost of Britain's clean, green wind power experiment: Pollution on a disastrous scale". London: Daily Mail. Retrieved 2011-03-02.
- Hilsum, Lindsey (6 December 2009). "Chinese pay toxic price for a green world". London: The Sunday Times. Retrieved 2011-03-02.
- Bradsher, Keith (26 December 2009). "Earth-Friendly Elements Are Mined Destructively". The New York Times. Retrieved 2011-03-02.
- Biggs, Stuart (6 January 2011). "Rare Earths Leave Toxic Trail to Toyota Prius, Vestas Turbines". Bloomberg L.P. Retrieved 2011-03-02.
- Ingebretsen, Mark. Developing greener, cheaper magnets Ames Laboratory. Accessed: 10 March 2011.
- Biello, David (13 October 2010). "Rare Earths: Elemental Needs of the Clean-Energy Economy". Scientific American. Retrieved 2011-03-02.
- Enercon explanation on p.4 on avoidance of Neodymium use
- New South Wales Government (1 November 2010). The wind energy fact sheet Department of Environment, Climate Change and Water, p. 13
- American Wind Energy Association (2009). Annual Wind Industry Report, Year Ending 2008 pp. 9-10.
- "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. Retrieved 2006-04-21.
- 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
- Erich Hau. Windkraftanlagen: Grundlagen, Technik, Einsatz, Wirtschaftlichkeit, Berlin: Heidelberg 2008, pp. 621–623. (German). (For the english Edition see Erich Hau, Wind Turbines: Fundamentals, Technologies, Application, Economics, Springer 2005)
- Forest clearance for Meyersdale, Pa., wind power facility
- Statement of the Government of Brandenburg, Germany.
- "Canada's First Urban Wind Turbine - Not Your Average Windmill". Toronto Hydro. 2006-02-06. Archived from the original on 2008-03-30. Retrieved 2008-04-11.
- Gilligan, Andrew (February 23, 2013). "Wind farms will create more carbon dioxide, say scientists". Telegraph. Retrieved 27 February 2013.
- Stevenson, Tony Struan (20 May 2009). "Bid to ban peatland wind farms comes under attack". Sunday Herald (newsquest (sunday herald) limited). Retrieved 20 May 2009.
- Zehnder and Warhaft, Alan and Zellman. "University Collaboration on Wind Energy". Cornell University. Retrieved 17 August 2011.
- Sovacool, Benjamin K. (2013). "The avian benefits of wind energy: A 2009 update". Renewable Energy 49: 19. doi:10.1016/j.renene.2012.01.074.
- "U.S. Fish & Wildlife Estimate of Bird Mortality Due to Wind Turbines". Letter to the Department of the Interior. American Bird Conservancy. 22 March 2012. Retrieved 6 December 2012.
- Smallwood, K. S. (2013). "Comparing bird and bat fatality-rate estimates among North American wind-energy projects". Wildlife Society Bulletin 37: 19–33. doi:10.1002/wsb.260.
- Ruane, Laura (6 November 2008). "Newest Air Defense: Bird Dogs". USA Today. Retrieved 6 December 2012.
- Contaminant Issues - Oil Field Waste Pits, U.S. Fish & Wildlife Service, U.S. Department of the Interior. Retrieved July 30, 2013.
- Johns, Robert. Actions by Feds Cut Annual Bird Deaths in Oil and Gas Fields by Half, Saving Over One Million Birds From Grisly Death, Washington, D.C.: American Bird Conservancy, January 3, 2013. Retrieved July 30, 2013.
- Bird, David Michael. The Bird Almanac: The Ultimate Guide to Essential Facts and Figures of the World's Birds, Key Porter Books, 1999, ISBN 155263003X, ISBN 978-1552630037.
- North-Hager, Eddie. "Millions of Birds Perish at Communication Towers, USC Study Finds". University of Southern California. Retrieved 6 December 2012.
- Foderaro, Lisa W. Researching Stop Signs in the Skies for Birds, May 14, 2014, p. A21 (New York edition), and May 13, 2014 online. Retrieved from nytimes.com on May 14, 2014. Quote: "In January, scientists concluded that, nationwide, 365 million to 988 million birds die annually after crashing into buildings and houses."
- "Cats Indoors! The American Bird Conservancy's Campaign for Safer Birds and Cats". National Audubon Society. Retrieved 6 December 2012.
- Angier, Natalie. , The New York Times, January 29, 2013, Retrieved January 30, 2013.
- U.S. Cats Kill Up To 3.7 Billion Birds, 20.7 Billion Small Mammals Annually, Paris: Agence France-Presse, January 29, 2013. Retrieved from The Globe & Mail website, January 30, 2013.
- UK's most powerful wind farm could power Paisley, British Wind Energy Association, January 2006.
- 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.
- Craig K.R. Willis, Robert M.R. Barclay, Justin G. Boyles, R. Mark Brigham, Virgil Brack Jr., David L. Waldien, Jonathan Reichard (2010). "Bats are not birds and other problems with Sovacool's (2009) analysis of animal fatalities due to electricity generation". Energy Policy 38 (4): 2067. doi:10.1016/j.enpol.2009.08.034.
- Lorenzini, Paul (April 30, 2013). "Nukes kill more birds than wind?". Atomic Insights. Retrieved 26 August 2013.
- “… the study already tells you the numbers are very rough estimates that need to be improved. I even explicitly state this, as well, in the conclusion: ‘the rudimentary numbers presented here are intended to provoke further research and discussion,’ in the abstract ‘this paper should be respected as a preliminary assessment,’ and in the title of the study, which has the word ‘preliminary’ in it...you are correct that errors 1 and 2 are true...” Benjamin Sovacool, Benjamin Sovacool takes issue with Lorenzini’s criticism of his work, Atomic Insights website, 11 July 2013.
- K. Shawn Smallwood, “Comparing bird and bat fatality-rate estimates among North American wind-energy projects”, Wildlife Society Bulletin, 26 Mar. 2013.
- "Estimates of bird collision mortality at wind facilities in the contiguous United States Scott R. Lossa et. al.".
- "Study: California Wind Power is the Worst For Wildlife, Chris Clarke, November 2013.".
- Barclay, Robert; E. F. Baerwald, J.C. Gruver (2007). "Variation in bat and bird fatalities at wind energy facilities". Journal of Zoology. Retrieved 6 December 2012.
- Marris, Emma; Daemon Fairless (10 May 2007). "Wind farms' deadly reputation hard to shift". Nature 447 (7141): 126. Bibcode:2007Natur.447..126M. doi:10.1038/447126a. Retrieved 28 June 2013.
- Emma Marris; Daemon Fairless (10 May 2007). "Wind farms' deadly reputation hard to shift". Nature 447 (7141): 126. Bibcode:2007Natur.447..126M. doi:10.1038/447126a. (subscription required)
- Sahagun, Louis (16 February 2012). "U.S. probes golden eagles' deaths at DWP wind farm". Los Angeles Times. Retrieved 6 December 2012.
- 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.
- Austen, Ian. Casualties of Toronto’s Urban Skies, The New York Times, October 28, 2012, p. A6. Retrieved online November 2, 2012.
- Kennedy, Joe. Country Matters: City Birds Battered To Oblivion, Dublin, Ireland: Sunday Independent, November 4, 2012. Retrieved online, November 4, 2012.
- Lomborg, Bjørn (2001). The Skeptical Environmentalist. New York City: Cambridge University Press.
- 10,000 Birds Trapped In The World Trade Center Light Beams, StapleNews, September 16, 2010.
- Johnston, D; Haines (1957). "Analysis of Mass Bird Mortality in October, 1954". The Auk 74 (4): 447. doi:10.2307/4081744.
- Fitch, Davey. Upland birds face displacement threat from poorly sited wind turbines (press release), Royal Society for the Protection of Birds website, September 26, 2009. Retrieved August 2, 2013. This press release in turn cites:
- Elliott, Valerie (28 January 2006). "Wind Farms Condemned As Eagles Fall Prey To Turbines". The Times. Retrieved Accession No.: 7EH1804703031.
- McDermott, Matthew (2 May 2009). "Texas Wind Farm Uses NASA Radar to Prevent Bird Deaths". Treehugger. Retrieved 6 December 2012.
- "Wind Turbines A Breeze For Migrating Birds". New Scientist (2504): 21. 18 June 2005. Retrieved 6 December 2012.
- Desholm, Mark; Johnny Kahlert (9 June 2005). "Avian Collision Risk At An Offshore Wind Farm". Biology Letters 1 (3): 296–298. doi:10.1098/rsbl.2005.0336. Retrieved 6 December 2012.
- Bob Yirka (15 August 2012). "British researchers find geese alter course to avoid wind farm". Phys.org. Retrieved 6 December 2012.
- Dalton, Andrew (7 December 2010). "Altamont Pass to Get Less-Deadly Wind Turbines". SFist. Retrieved 6 December 2012.
- "Federal Environmental Impact Statement for Chokecherry and Sierra Madre Wind Energy project". Bureau of Land Management. 3 July 2012. Retrieved 6 December 2012.
- "Caution Regarding Placement of Wind Turbines on Wooded Ridge Tops" (PDF). Bat Conservation International. 4 January 2005. Retrieved 2006-04-21.
- "Effectiveness of Changing Wind Turbine Cut-in Speed to Reduce Bat Fatalities at Wind Facilities" (PDF). American Wind Energy Association. 2009-04-28. Retrieved 2009-04-28.
- Aron, Jacob (2009-07-17). "Radar beams could protect bats from wind turbines". London: The Guardian. Retrieved 2009-07-17.
- Nicholls, Barry; Racey, Paul A. (2007). "Bats Avoid Radar Installations: Could Electromagnetic Fields Deter Bats from Colliding with Wind Turbines?". In Cresswell, Will. PLoS ONE 2 (3): e297. Bibcode:2007PLoSO...2..297N. doi:10.1371/journal.pone.0000297. PMC 1808427. PMID 17372629. Lay summary – The Guardian (2009-07-17).
- Morin, Monte. 600,000 bats killed at wind energy facilities in 2012, study says, LA Times, November 8, 2013.
- Turbines and turbulence, Nature (journal), 468, 1001, 23 December 2010, DOI:10.1038/4681001a, published online 22 December 2010.
- Somnath Baidya Roy and Justin J. Traiteur. Impacts of wind farms on surface air temperatures, Proceedings of the National Academy of Sciences, Vol. 107, No. 42, October 19, 2010, p. 17,899.
- Wind farms impacting weather, Science Daily.
- The influence of large-scale wind power on global climate — PNAS
- MIT analysis suggests generating electricity from large-scale wind farms could influence climate — and not necessarily in the desired way MIT, 2010.
- New South Wales Government (1 November 2010). The wind energy fact sheet, Department of Environment, Climate Change and Water of New South Wales, p. 12.
- Gourlay, Simon. Wind farms are not only beautiful, they're absolutely necessary, The Guardian, 12 August 2008.
- "Tourism blown off course by turbines". Berwickshire: The Berwickshire News. 2013-03-28. Retrieved 2013-10-08.
- Young, Kathryn (2007-08-03). "Canada wind farms blow away turbine tourists". Edmonton Journal. Retrieved 2008-09-06.
- Zhou, Renjie; Yadan Wang (2007-08-14). "Residents of Inner Mongolia Find New Hope in the Desert". Worldwatch Institute. Retrieved 2008-11-04.
- "Centre d'interprétation du cuivre de Murdochville". Retrieved 2008-11-19. - The Copper Interpretation Centre of Murdochville, Canada features tours of a wind turbine on Miller Mountain.
- Dipert, Brian. Cutting the carbon-energy cord: Is the answer blowin' in the wind?, EDN Network website, December 15, 2006.
- Rod Thompson (20 May 2006). "Wind turbine lights have opponents seeing sparks". Honolulu Star-Bulletin. Retrieved 2008-01-15.
- Simon Chapman (December 21, 2011). "Much angst over wind turbines is just hot air". Sydney Morning Herald.
- Alison Rourke (15 March 2013). "Windfarm sickness spreads by word of mouth, Australian study finds". The Guardian.
- Barnard, Mike. Wind Energy: Is Dr. Nina Pierpoint's "Wind Turbine Syndrome" a real medical syndrome caused by wind turbines?, Quora.com website, May 2, 2012.
- Pierpont, Nina (7 March 2006). "Wind Turbine Syndrome: Testimony before the New York State Legislature Energy Committee". Save Western NY. Retrieved 29 April 2010.
- Committee on Environmental Impacts of Wind Energy Projects, National Research Council (2007). Environmental Impacts of Wind-Energy Projects, p. 158-9.
- General Purpose Standing Committee No. 5, Parliament of New South Wales (16 December 2009). "Final Report, Rural Wind Farms".
- National Health and Medical Research Council (July 2010). Wind Turbines and Health public statement.
- Ministry of the Environment, Ontario (October 2008) "Noise Guidelines for Wind Farms"
- Ministry of the Environment, Ontario (9 June 2009). "Wind Turbines – Proposed Requirements and Setbacks"
- 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.
- New South Wales Government (1 November 2010). The wind energy fact sheet Department of Environment, Climate Change and Water, p. 8.
- Turbine goes up in flames Retrieved August 26, 2013.
- Brown, Curt. Dartmouth Select Board OKs Permit For Two Wind Turbines, SouthCoastToday.com January 05, 2010. Retrieved February 8, 2012.
- Major Offshore Wind Farm Fitted With Fire Extinguishers, Infor4Fire.com website, August 19, 2011. Retrieved February 8, 2012.
- Fire Protection For Wind Turbines: Safe For Certain – MiniMax, Minimax.de website. Retrieved February 8, 2012.
- Aspirating Smoke Detector AMX4004 WEA For Wind Energy Plants: Cool Down Fire Protection By Minimax, Minimax.de website. Retrieved February 8, 2012.
- Built-in fire brigade: water vs nitrogen; Dealing with fire is likely to become an increasingly hot topic for the wind turbine business, Modern Power Systems, May 1, 2007.
- Wardrop, Murray (2008-12-04). "Wind turbine closed after showering homes with blocks of ice". The Daily Telegraph (London).
- Study finds offshore wind farms can co-exist with marine environment, BusinessGreen.com website.
- UK Offshore Energy: Strategic Environmental Assessment, UK Department of Energy and Climate Change, January 2009.
- Warwicker, Michelle. "Seals 'feed' at offshore wind farms, study shows" BBC, 21 July 2014. Accessed: 22 July 2014. Video of seal path
- Robert Gasch, Jochen Twele (ed.), Wind power plants. Fundamentals, design, construction and operation, Springer 2012 ISBN 978-3-642-22937-4.
- Erich Hau, Wind turbines: fundamentals, technologies, application, economics Springer, 2013 ISBN 978-3-642-27150-2 (preview on Google Books)
- Alois Schaffarczyk (ed.), Understanding wind power technology, Wiley & Sons 2014, ISBN 978-1-118-64751-6.
- Hermann-Josef Wagner, Jyotirmay Mathur, Introduction to wind energy systems. Basics, technology and operation. Springer 2013, ISBN 978-3-642-32975-3.
- NWCC. National Wind Coordinating Collaborative website, facilitated by the American Wind and Wildlife Institute, includes its updated summaries of wind-wildlife interactions from 2010.