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A wind farm is a collection of wind turbines in the same location and used for the generation of wind power electricity.
Wind farms present an economy of scale along with an efficiency factor that enable them to produce electricity in the price range of conventional energy sources, and hence compete with conventional grid power.
See also: PowerPedia:Windfarms - needs to be combined with this page.
- Vortex / Wind > Farms > VAWT >
Can This Egg Beater Double the Power Output of Wind Farms? - Wind Harvest International places three or more counter-rotating turbines next to each other to create a vortex. The small-scale cyclone that results effectively increases the available amount of harvestable energy. Could the placement of these on the ground within existing wind farms double the net output? (GreenTechMedia; March 24, 2010)
Different Types of Wind Farms
- Wind > Piezoelectrics / Farms / Piezoelectricity >
Windstalk concept is a wind farm without the turbines - An interesting Windstalk concept devised by New York design firm Atelier DNA could overcome the aesthetics and vibrations contentions to wind farms while still allowing a comparable amount of electricity to be generated by the wind. The array of densely arranged poles are packed with a stack of piezoelectric ceramic discs. Fluid in the base of the poles would turn turbines. (GizMag; October 13, 2010)
Wind farms in the United States
The U.S. has several of the largest wind farms in the world. Three of the largest, Altamont Pass, San Gorgonio Pass and Tehachapi Pass, are located in California. The largest U.S. wind farm is the Stateline Wind Project on the Oregon-Washington line, with a peak capacity of 300 megawatts of electricity (although the three California wind farms mentioned are larger, they are actually collections of dozens of individual wind farms). The California wind farms have many different owners and turbine types and have been constructed, retrofitted and occasionally dismantled since they were first installed in late 1982. As of 2005 all three of these areas are seeing renewed growth. Primarily, the old, small wind turbines are being replaced with much larger, more efficient wind turbines. Some of the workhorses of the past were only 65 kilowatts (kW) in capacity size or even smaller, though some were several hundred kW. Today, the smallest utility-scale wind turbines are about 700 kW, with a few models approaching 5,000 kW (5 MW). Secondarily, non-functional turbines are also being returned to service.
The Altamont Pass in Northern California is one of the earliest large wind farms. It is composed of large numbers of relatively small wind turbines of various types that were installed after the 1970s energy crisis in response to favorable tax policies for investors. However, the types of incentives the government uses have led to an unhealthy cycle of booms and busts for the wind energy industry. The problems were not so much with the wind turbines themselves. Only a few of the turbine designs were fatally flawed and almost all of the others were able to be rehabilitated into excellent machines. Still, these numerous small turbines are being gradually replaced with much larger and more cost-effective units. An advantage of the Altamont Pass site is that under hot inland (Central Valley) conditions, a thermal low is developed that brings in cool coastal marine air, driving the turbines at a time of maximum electricity demand. However, this phenomenon is not always reliable and with an inland high pressure condition the entire region can be both hot and windless. At this time additional power must be provided by natural gas-powered gas turbine peaker plants. The turbines are dangerous to various raptors that hunt ground squirrels in the area and sometimes collide with the machines.YouTube. (U.S.) Today's turbines are larger and spaced farther apart, as that has proven to be a more cost-effective approach.
The Tehachapi Pass and San Gorgonio Pass sites have not had the same problems as Altamont Pass has had. The winds at these sites are more consistent. Also, endangered bird kills have not been an issue.
Even though California has the largest wind farms in the U.S., it does not have very many commercially viable wind farm sites, at least not onshore. Much of the Southwest is not much better, although there are some significant exceptions. However, the Midwest has an abundance of suitable sites for wind energy development and yet the region's potential has gone largely untapped. As of 2005, several sites have been constructed or are in development in the Midwest. The Pacific Northwest and the Northeast both have many excellent sites as well. In contrast, the Southeast has a very poor wind energy resource, though the Appalachian Mountains do provide a few good areas.
The new "Maple Ridge Wind Farm" near Lowville, NY may currently be the largest wind farm in the USA. The name was changed to honor the production of Maple Syrup from this region of Northern New York. More information is available at: MapleRidgeWind.com. This site has 195 Vestaswind turbines, each with a rated capacity of 1.65MW, resulting in a rated site capacity of 320MW (equivalent to a mid-sized power plant). The site was dedicated on Sept. 26, 2006 with all but one turbine in operation (one tower was damaged in shipping and is waiting for replacement). Maple Ridge (formerly Flat Rock Wind Farm) provides about $10 million in benefit to the local community with about $2 million annual payments to 75 landowners, and $8 million in tax revenues to the region. This site has increased New York's renewable energy generation by six-fold. The project is jointly owned by PPM Energy and Horizon Wind Energy.
In West Virginia the "Mountaineer Wind Energy Center" near Thomas has been operational since December 2002. It consists of 44 turbines generating 66MW. The site is owned by FPL Energy.
In Massachusetts, two proposed wind farms have had approval difficulties. The Cape Wind project, a proposal to construct 130 offshore wind turbines in the Nantucket Sound, is the subject of heavy debate in the affluent communities of Cape Cod, Martha's Vineyard, and Nantucket as well as among environmentalists. The Hoosac Wind project, which will build 20 turbines on two ridgelines in the rural towns of Florida and Monroe, was initially the subject of little official controversy, but has been delayed by a suit to protect wetlands. Several other projects have been proposed for the area.
Another 40-turbine offshore wind power installation has been proposed for the ocean off Jones Beach, Long Island, New York. It has the backing of many local and national environmental groups  as well as the Long Island Power Authority and the Governor of New York.
In New Jersey, the country's first coastal wind farm became operational in December 2005. The Jersey-Atlantic Wind Farm in Atlantic City consists of five 1.5-MW turbines.
New Mexico is home of the New Mexico Wind Energy Center near Fort Sumner, New Mexico, having 136 turbines with a peak output of 1.5 megawatts each. Ironically, this site is owned by FPL Energy; i.e. Florida Power and Light. PNM claims  that this facility is the world's third largest wind generation project, but this page appears to be approximately three years old and the project's ranking may have changed.
The American Wind Energy Association provides information about existing and proposed projects in the U.S.
As of May 31, 2006, the FAA has stopped construction at 15 midwest wind farm projects over concerns about interference with military radar. The reason for this is that a defense appropriation bill passed in January 2006 contained a provision requiring studies of the effects of wind farms on military radar, language added to the bill by Cape Wind project opponents. Since then, the FAA has began permitting construction to resume, as no evidence of any radar difficulty has been found (or ever was suspected).
Wind Farms in China
- How China is backing the power of wind - Dabancheng, 'The Three Gorges of the sky'. It is a spectacular sight: fields of spinning blades harvesting energy and transforming it into electricity for the nearby city of Urumqi. A few years ago, this was the only wind farm of such a size in China. But now, bigger facilities have been built or are under construction in Gansu, Inner Mongolia and Jiangsu. Since 2005, the country's wind generation capacity has increased by more than 100% a year. (Khaleej Times; July 27, 2008)
Wind farms in Europe
The development of wind farms in Europe enjoys greater public acceptance and creates a larger share of energy. Germany has the biggest wind turbine to be established offshore, and the largest number of wind farms in the world.
Governmental policy is generally in favour of increasing the use of renewable energy sources. The United Kingdom government, for example, has a target for 10% of domestic energy consumption to be generated from renewable sources by the year 2010. A number of on- and off-shore wind farms are currently going through planning permission at the moment. Recently an onshore farm was opened at Cefn Croes in West Wales's Cambrian Mountains . In May 2006, operational wind farms in the UK comprised an installed capacity of 1693 MW, in Portugal 1188 MW , in France 918 MW and in the Republic of Ireland 496 MW. The planned 322 MW wind farm south of Glasgow will be the biggest wind farm in Europe. The €350 million farm is ordered by Scottish Power and the 140 wind turbines are to be delivered by Siemens.
On 18th December 2006, the British government gave planning consent for the world's largest offshore wind farm. It is to be built 12 miles off of the Kent coast and will include 341 turbines. Parts of the 'London Array', as it is called, have already been constructed and are operational.
Wind farms in different countries yield different amounts of electricity, because of differences in prevailing wind patterns, siting of the turbines, and the fact that early turbine designs were considerably less efficient and capable of adapting quickly to changes in wind direction and speed. For example, an Oxford University study of the wind over the past 35 years found that UK turbines would have produced 27% of their maximum possible energy, compared with 20% in Denmark and 15% in Germany. 
Wind farms in Japan
There is no particular controversy about the sightliness or otherwise of the Wakamatsu ward windfarm in Kitakyushu, as there is in some other countries. It is far from the scenic areas of Wakamatsu, and on windy reclaimed land. Asahi Shimbun reported on May 18, 2005 that many utilities have put limits on the amount of wind power they will allow, because of lack of confidence in their ability to deal with the variable output. It should be noted that several European countries are successfully accommodating significantly higher shares of wind energy in to their networks and that the Japanese grid is capable of coping with large conventional power stations disconnecting unexpectedly due to faults; on the other hand, it is true that integrating windpower or unreliable conventional power stations in to island grids is more difficult than into continent-wide inter-connected grids.
Wind farms in Canada
The total capacity of all wind farms in Canada is approximately 1,341 MW as of November 2006 . Each province and territory contains the following capacity (rounded to one decimal):
- Ontario, 413.0 MW,
- Alberta, 384.2 MW,
- Quebec, 212.3 MW,
- Saskatchewan, 171.2 MW,
- Manitoba, 104.0 MW,
- Nova Scotia, 41.5 MW,
- Prince Edward Island, 13.6 MW,
- Yukon, 0.8 MW, and
- Newfoundland, 0.4 MW.
There are currently no wind projects listed for British Columbia, New Brunswick, Nunavut (territory), or the Northwest Territories.
The five largest wind farms in Canada are:
- Prince Project - Phase I&II (Ontario), 189 MW
- Murdochville Project - Phase I&II&III (Quebec), 162 MW
- Centennial (SaskPower near Swift Current, Saskatchewan), 149.4 MW
- Erie Shores (Ontario), 99 MW
- St Leon - Phase 2 (Manitoba), 84 MW
Government support for wind power continues to increase. The current Wind Power Production Incentive (WPPI) is expected to quadruple its goal of 1,000 MW of wind power to 4,000 MW. There is an additional 2,811 MW planned or under construction.
- See also: List of wind farms in Canada
Wind farms in Australia
As of May 2006, there were 444 wind turbines in Australia with a total generating capacity of about 638 megawatts. Another 130 turbines are currently under construction, respresenting an additional 250MW. Nationally, wind farms contribute about 1% of total electricity production. In the state of South Australia, this figure is much higher at 9.2% (2005). Australian wind farms produce on average capacity factors of 30-35%, making wind an attractive option in the country.
The largest wind farms in Australia are:
- Wattle Point (SA) - 90.75MW
- Alinta/Walkaway (WA) - 90MW
- Lake Bonney Stage 1 (SA) - 80.5MW
- Cathedral Rocks (SA) - 66MW
- Blayney (NSW) - 9.9 MW
- Crookwell (NSW) - 4.8 MW
- Hampton (NSW) - 1.3 MW
- Kooragang Island (NSW) - 0.6 MW
Wind farms in New Zealand
Genesis Energy built the Hau Nui wind farm in 1996 and is located south east of Martinborough on the coastal road to White Rock.
The Brooklyn Wind Turbine was installed on the top of a hill in Brooklyn, Wellington in March 1993 as part of a research project by Meridian Energy. Meridian Energy is currently building a consignment of wind farms in the rural Makara Hill area west of Wellington and have finished the Te Apiti wind farm on the Ruahine Ranges. It can be seen clearly at Ashurst near Palmerston North.
Trust Power purchased the Tararua wind farm from Tararua Wind Power Limited. It is on the Tararua Ranges behind Palmerston North.
Wind farms in South Africa
The first commercial wind farm in South Africa is being planned for construction near the town of Darling situated on the west coast north of Cape Town after a long battle for regulatory approval. South African's electricity parastatal Eskom recently announced a 100 MW wind farm to be built on the West Coast near the town of Koekenaap.
Wind farms in India
At the end of March 2000 India had 1080-MWs capacity wind farms, of which Tamil Nadu contributed 770-MW capacity. Gujarat has 167MW followed by Andhra Pradesh, which has 88 MW installed wind farms. There are about a dozen wind pumps of various designs providing water for agriculture, afforestation, and domestic purposes, all scattered over the country. The states of Tamil Nadu and Gujarat lead in the field of wind energy.
In the News
- Alaska: the Clean Energy Frontier? - Wind turbines are popping up all over Alaska. The Alaska Energy Authority charged with reducing energy costs in Alaska, is recommending grants for 72 renewable energy projects, and all but a few of the projects are expected to save money over the project life. (GreenInc; Feb 18, 2009)
- Connecting wind farms - Wind power, long considered to be as fickle as wind itself, can become a dependable source of electricity at a lower cost, according to scientists at Stanford University. The key is connecting wind farms throughout a given geographic area with transmission lines, combining the outputs into one powerful energy source. (PhysOrg; Nov. 21, 2007)
- Wind energy generation in USA increases by 45% in 2007 - According to the American Wind Energy Association, the wind energy generation capacity in the United States grew 45% in 2007, and is now 16 818 MW. Wind accounted for 30% of all new generating capacity added throughout the country in 2007. (African Energy News Review; Feb. 6, 2008)
Wind Power Is On The Rise, Despite The Controversy
Government and Politics
- Washington State Supreme Court Upholds EFSEC Permit for Kittitas Valley Wind Power Project - Horizon Wind Energy (Horizon), owned by EDP Renovaveis, the fourth largest wind energy producer in the world, applauded the Washington State Supreme Court's unanimous ruling to uphold the Kittitas Valley Wind Power Project's (KVWPP) Energy Facility Site Evaluation Council (EFSEC) Permit previously signed by Governor Christine Gregoire. (MarketWatch; Nov. 20, 2008)
The following subsections outline some of the current controversies concerning wind power.
Cost and Reliability
- Wind > Farms > Cost and Reliability >
Does this Picture Spell Doom for Wind Power? - The wrong kind of wind? It's a phrase that haunts those desperately trying to justify wind farms in Britain. However, apologists for the giant turbines now face the unpalatable truth that structures designed to operate in windy conditions literally fell flat on their faces when the wind became a bit too strong. According to the latest figures, one turbine worked at 15 per cent of its capacity last year, generating generated electricity worth an estimated £100,000 but had to be subsidised with £130,000 of public money. (Express.co.uk; December 11, 2011)
One of the major questions raised about use of wind power is its ability to serve as a large-scale energy source. Reliability of wind power is viewed by some as a major obstacle to increased integration, while others argue that its cost is too high. A recent report by the Utility Wind Interest Group (UWIG) stated that "On the cost side, at wind penetrations of up to 20% of system peak demand, system operating cost increases arising from wind variability and uncertainty amounted to about 10% or less of the wholesale value of the wind energy." The report added that some of this cost increase can be reduced by using wind forecasting and other means. The report also stated that "The addition of a wind plant to a power system increases the amount of variability and uncertainty of the net load. This may introduce measurable changes in the amount of operating reserves required for regulation, ramping and load-following. [...] In two major recent studies, the addition of 1,500 MW and 3,300 MW of wind (15% and 10%, respectively, of system peak load) increased regulation requirements by 8 MW and 36 MW, respectively, to maintain the same level of NERC control performance standards. [...] [V]ariability and uncertainty introduced by wind plants have been shown to increase system operating costs by up to about $5/MWH at wind penetration levels up to 20%." With regard to reliability, the report states, "Further, there is evidence that with new equipment designs and proper plant engineering, system stability in response to a major plant or line outage can actually be improved by the addition of wind generation."
Effects on the community
Wind farms have been opposed by those who feel that the siting of some of them spoil the landscape, particularly in countryside areas of outstanding natural beauty where there is otherwise no industrialisation nor development (e.g. Snowdonia, Cumbria). Others say they feel that the wind turbines are beautiful regardless where they are sited.
A study by the University of St Andrews of 2 Scottish and one Irish site found that support for wind farms was higher among those living near existing sites, than among those living near proposed sites. The study also found that, in the case of the Dun Law Wind Farm in the Scottish Borders, that support for the farm was lowest among residents living 10-20 km away, with support being higher closer to the farm. However, none of these sites involved areas of outstanding natural beauty.
Other criticisms include noise and vibration produced by the blades, gears, and motors, the flashing lights required on the tall towers (for aviation safety), the shadows cast by the rotating blades, and many more. At the same time, there are many neighbors of wind facilities who report no problems with them (see, for example, testimonials collected by the Alliance for Clean Energy New York, an advocacy group).
Some question whether windmills are a significant danger to passing birds. One large wind farm in California's Altamont Pass has been shown to kill 300 red-tailed hawks and 60 golden eagles a year. However, the pass is an area with very high year-round raptor use, and the raptor mortality rate there is far higher than at other wind farms. In the UK, the Royal Society for the Protection of Birds (RSPB) has studied this matter and concluded that "The available evidence suggests that appropriately positioned wind farms do not pose a significant hazard for birds" (see RSPB statement on wind farms). It notes that climate change poses a much more significant threat to wildlife, and therefore supports wind farms and other forms of renewable energy.
A study of a Danish offshore wind farm used radar to track flocks of geese and eider ducks around the Nysted wind farm in the Baltic sea. It found that the birds flew almost exclusively down the corridors between the 72 turbines, with less than one per cent flying close enough to risk collision. Many also avoided the wind farm altogether. The study was by Mark Desholm and Johnny Kahlert of the National Environmental Research Institute in Rønde, Denmark (New Scientist, vol 186, no 2504: 18 June 2005). The study did not, however, use data during twilight hours or anything more than mild winds, and the researchers warn about the possible cumulative effect of increasing numbers of wind facilities.
A Norwegian wind farm built on the Smøla islands has raised environmental concerns as nine sea eagles have died after colliding with turbine rotor blades. These deaths all occurred after the opening in September 2005 of Phase 2 of the wind farm . These deaths included all of the previous year's chicks, and the number of breeding pairs on the islands reduced from 19 to one in the same period .
Problems of Wind Farm implementation
By themselves, wind farms are not suitable for replacement of base-load electricity supply, such as that supplied by coal-fired or nuclear power stations. This is because wind power output is variable and unpredictable with sufficient accuracy. As a result, continuity of electricity supply needs to be assured both by having loads that can be switched off at times of high demand, and by having power generation facilities that can be ramped up in approximately the same timescale that wind power diminishes. Such power generation types are generally more expensive per unit of electricity generated than base-load generators, so electricity suppliers prefer to minimise their use. Still, electricity demand on a power system varies throughout the day, and the additional variability introduced by wind generation is modest. The Utility Wind Integration Group, reviewing the state of the art in utility integration of wind, comments: "Given the existing uncertainties in load forecasts . . . studies indicate that the requirement for additional reserves will likely be modest for broadly distributed wind plants."
Wind power also suffers as it generates electricity that is decoupled from demand - the wind does not stop blowing when industrial activity stops for the night, for example. Storage methods for power generated in excess of demand are limited by the technology available in the first decade of the 21st century. Some schemes that reverse hydroelectric operation by pumping water to replenish hydroelectric reservoirs are in operation, but such schemes are inefficient (70-85% efficiency - see Pumped-storage hydroelectricity), and depend on favourable geography. A new solution currently being piloted is the use of rechargeable flow batteries as a rapid-response storage medium . Vanadium redox flow batteries are currently installed at Huxley Hill wind farm (Australia), Tomari Wind Hills at Hokkaido (Japan), as well as in other non-wind farm applications. A further 12 MWh flow battery is to be installed at the Sorne Hill wind farm (Ireland) .
The above problems are mitigated in part by increasing the scale of implementation. With more wind farms spread over a wider area, it is less likely that all the wind farms will simultaneously experience low-wind conditions. The area required is large, however, as low-wind high-pressure regions can form that cover most of Western Europe and or the British Isles for long periods in Northern Hemisphere summers. In addition, although pumped storage is inefficient, once the capital investment is made in the wind farm infrastructure, the marginal cost of generating the power to pump water is small. Pumped storage also provides a reservoir of power that can be ramped up quickly to even out short term wind power fluctuations.
Integrating wind power with existing systems can also be tricky. A recent article by the UWIG stated that "Upgrades or additions to transmission facilities may be needed to access locations with large wind-energy potential. Current transmission planning processes are able to identify solutions to transmission problems, but the time required for implementation of solutions often exceeds wind-plant permitting and construction times by several years."
- Solar > Problems / Wind > Farms > Downsides >
Renewable "Green" Energy Yields Very Poor Results - A 1 GW wind farm would require 500 windmills, each producing 2 MW -- assuming the farm operates at full capacity, which doesn't happen continually in reality. Since wind turbines must be spaced apart to maximize production, a 1 GW farm needs from 48,000 to 64,000 acres of land (75 to 100 square miles). In contrast, a 1 GW gas-fired plant needs about 10 to 15 acres. (MadIsle / Newsmax; January 30, 2012)
- Wind > Farms > Cautions >
Wind farms produced 'practically no electricity' during Britain's cold snap - The cold weather has been accompanied by high pressure and a lack of wind -- something that could turn into a crisis when the UK is reliant on 6,400 turbines accounting for a quarter of all UK electricity demand over the next 10 years. (Telegraph; UK; Jan. 11, 2010)
- Wind Turbine Overspeed Failure -The braking system failed in the Vesta Wind Turbine, while 2 technicians worked in the turret in the top of the 10-year old fiberglass tower and were able to get out before the collapse near Hornslet, Denmark in February 2008. A Vestas wind system fails and crashes (Video) (North American Windpower; March 28, 2008)
- Wind Energy Bumps Into Power Grid’s Limits - Maple Ridge Wind farm cost $320 million to put nearly 200 wind turbines in upstate New York, but at times, regional electric lines have been so congested, that Maple Ridge has been forced to shut down, even with a brisk wind blowing. (Slashdot) (New York Times; Aug. 26, 2008)
See Discussion page
- Wind Over Water - a documentary film about the Cape Wind Project a proposed wind farm in Massachusetts, US.
- Altahullion Wind farm A Quicktime VR panorama illustrating the scale of the largest wind farm in Ireland
- "The Low Benefit of Industrial Wind", a paper presenting the record and projections of wind power's contribution to the grid
- Wind power
- MySME.deInformation on Wind Farm Development in Germany
- Offshorewind.net - Offshore wind energy information.
- American Wind Energy Association. An association promoting wind power growth through advocacy and education.
- Birdlife.org Wind farm causes eagle deaths
- Living In New York An amalgam of NY groups presenting evidence on environmental and health effects of industrial turbines
- Research on Wind Power & Golden Eagles
- Eagles and windfarms.
- Windfarm ditched to safeguard eagles.
- Pictures of a Wind Farm being deployed
- Fabricante de torres español
- News:Wind | 2010 | 2009 | 2008
- PowerPedia:Wind power | PowerPedia:Wind Turbine
- Directory:Wind:Past Developments
- Directory:Wind:Offshore | PowerPedia:Offshore Wind Power Drawbacks
- Directory:Wind Farms | PowerPedia:Windfarms
- Directory:High-Efficiency Horizontal Axis Wind Turbines
- Directory:Home Generation:Wind Turbine
- Directory:Vertical Axis Wind Turbines
- Directory:High Altitude Wind Power
- Directory:Wind Augmentation
- Directory:Power Via Atmospheric Pressure Differences
- Directory:Humdinger Windbelt
- Directory:Wind Power in the United Kingdom