![Electricity production by source](https://upload.wikimedia.org/wikipedia/commons/b/b0/Electricity_production_by_source.svg)
Wind power or wind energy is mostly the use of
wind turbine
A wind turbine is a device that converts the kinetic energy of wind into electrical energy. Hundreds of thousands of large turbines, in installations known as wind farms, now generate over 650 gigawatts of power, with 60 GW added each year. ...
s to
generate electricity. Wind power is a popular,
sustainable
Specific definitions of sustainability are difficult to agree on and have varied in the literature and over time. The concept of sustainability can be used to guide decisions at the global, national, and individual levels (e.g. sustainable livin ...
,
renewable energy
Renewable energy is energy that is collected from renewable resources that are naturally replenished on a human timescale. It includes sources such as sunlight, wind, the movement of water, and geothermal heat. Although most renewable energy ...
source that has a much smaller
impact on the environment than burning
fossil fuel
A fossil fuel is a hydrocarbon-containing material formed naturally in the Earth's crust from the remains of dead plants and animals that is extracted and burned as a fuel. The main fossil fuels are coal, oil, and natural gas. Fossil fuels m ...
s. Historically, wind power has been used in
sails
A sail is a tensile structure—which is made from fabric or other membrane materials—that uses wind power to propel sailing craft, including sailing ships, sailboats, windsurfers, ice boats, and even sail-powered land vehicles. Sails may ...
,
windmill
A windmill is a structure that converts wind power into rotational energy using vanes called windmill sail, sails or blades, specifically to mill (grinding), mill grain (gristmills), but the term is also extended to windpumps, wind turbines, and ...
s and
windpump
A windpump is a type of windmill which is used for pumping water.
Windpumps were used to pump water since at least the 9th century in what is now Afghanistan, Iran and Pakistan. The use of wind pumps became widespread across the Muslim world an ...
s but today it is mostly used to generate electricity.
Wind farm
A wind farm or wind park, also called a wind power station or wind power plant, is a group of wind turbines in the same location used Wind power, to produce electricity. Wind farms vary in size from a small number of turbines to several hundre ...
s consist of many individual wind turbines, which are connected to the
electric power transmission
Electric power transmission is the bulk movement of electrical energy from a generating site, such as a power plant, to an electrical substation. The interconnected lines that facilitate this movement form a ''transmission network''. This is ...
network
Network, networking and networked may refer to:
Science and technology
* Network theory, the study of graphs as a representation of relations between discrete objects
* Network science, an academic field that studies complex networks
Mathematics
...
. New
onshore (on-land) wind farms are cheaper than new
coal
Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams. Coal is mostly carbon with variable amounts of other elements, chiefly hydrogen, sulfur, oxygen, and nitrogen.
Coal is formed when dea ...
or
gas plants,
but expansion of wind power is being hindered by
fossil fuel subsidies
Fossil fuel subsidies are energy subsidies on fossil fuels. They may be tax breaks on consumption, such as a lower sales tax on natural gas for residential heating; or subsidies on production, such as tax breaks on exploration for oil. Or ...
.
Onshore wind farms have a greater visual
impact on the landscape than some other power stations.
Small onshore wind farms can feed some energy into the grid or provide power to isolated off-grid locations.
Offshore wind farms
Offshore wind power or offshore wind energy is the Wind power, generation of electricity through wind farms in bodies of water, usually at sea. There are higher wind speeds offshore than on land, so offshore farms generate more electricity per ...
deliver more energy per installed capacity with less fluctuations and have less visual impact. Although there is less offshore wind power at present and construction and maintenance costs are higher, it is expanding.
Offshore wind power currently has a share of about 10% of new installations.
Wind power is
variable renewable energy
Variable renewable energy (VRE) or intermittent renewable energy sources (IRES) are renewable energy sources that are not dispatchable due to their fluctuating nature, such as wind power and solar power, as opposed to controllable renewable ener ...
, so
power-management techniques are used to match supply and demand, such as:
wind hybrid power systems
Hybrid power are combinations between different technologies to produce power.
In power engineering, the term 'hybrid' describes a combined power and energy storage system.
Examples of power producers used in hybrid power are photovoltaics, ...
,
hydroelectric power
Hydroelectricity, or hydroelectric power, is electricity generated from hydropower (water power). Hydropower supplies one sixth of the world's electricity, almost 4500 TWh in 2020, which is more than all other renewable sources combined and ...
or other
dispatchable power sources, excess capacity, geographically distributed turbines, exporting and importing power to neighboring areas, or
grid storage
Grid energy storage (also called large-scale energy storage) is a collection of methods used for energy storage on a large scale within an electrical power grid. Electrical energy is stored during times when electricity is plentiful and inexpe ...
. As the proportion of wind power in a region increases the grid may need to be upgraded.
Weather forecast
Weather forecasting is the application of science and technology to predict the conditions of the atmosphere for a given location and time. People have attempted to predict the weather informally for millennia and formally since the 19th centu ...
ing allows the electric-power network to be readied for the predictable variations in production that occur.
In 2021, wind supplied over 1800
TWh TWH or twh could refer to:
* Tai Dón language, a language of Vietnam, Laos, and China
* Tai Wo Hau station, Hong Kong; MTR station code
* Tennessee Walking Horse, a breed of horse
* Toronto Western Hospital, a hospital in Toronto, Canada
* Tun ...
of electricity, which was over 6% of world electricity and about 2% of world energy.
With about 100
GW added during 2021, mostly
in China
IN, In or in may refer to:
Places
* India (country code IN)
* Indiana, United States (postal code IN)
* Ingolstadt, Germany (license plate code IN)
* In, Russia, a town in the Jewish Autonomous Oblast
Businesses and organizations
* Independ ...
and the
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...
, global installed wind power capacity exceeded 800 GW.
To help meet the
Paris Agreement
The Paris Agreement (french: Accord de Paris), often referred to as the Paris Accords or the Paris Climate Accords, is an international treaty on climate change. Adopted in 2015, the agreement covers climate change mitigation, Climate change a ...
goals to
limit climate change, analysts say it should expand much faster - by over 1% of electricity generation per year.
Regions in the higher northern and southern latitudes have the highest potential for wind power. In most regions, wind power generation is higher in nighttime, and in winter when PV output is low. For this reason, combinations of wind and
solar power
Solar power is the conversion of energy from sunlight into electricity, either directly using photovoltaics (PV) or indirectly using concentrated solar power. Photovoltaic cells convert light into an electric current using the photovoltaic e ...
are suitable in many countries.
Wind energy
![Lee Ranch Wind Speed Frequency](https://upload.wikimedia.org/wikipedia/commons/f/fa/Lee_Ranch_Wind_Speed_Frequency.svg)
Wind energy is the
kinetic energy
In physics, the kinetic energy of an object is the energy that it possesses due to its motion.
It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its accele ...
of air in motion, also called
wind
Wind is the natural movement of air or other gases relative to a planet's surface. Winds occur on a range of scales, from thunderstorm flows lasting tens of minutes, to local breezes generated by heating of land surfaces and lasting a few hou ...
.
Total wind energy flowing through an imaginary surface with area ''A'' during the time ''t'' is:
:
where ''ρ'' is the
density of air
The density of air or atmospheric density, denoted '' ρ'', is the mass per unit volume of Earth's atmosphere. Air density, like air pressure, decreases with increasing altitude. It also changes with variation in atmospheric pressure, temperature a ...
; ''v'' is the
wind speed
In meteorology, wind speed, or wind flow speed, is a fundamental atmospheric quantity caused by air moving from high to low pressure, usually due to changes in temperature. Wind speed is now commonly measured with an anemometer.
Wind speed ...
; ''Avt'' is the volume of air passing through ''A'' (which is considered perpendicular to the direction of the wind); ''Avtρ'' is therefore the mass ''m'' passing through A. ''ρv''
2 is the kinetic energy of the moving air per unit volume.
Power is energy per unit time, so the wind power incident on ''A'' (e.g. equal to the rotor area of a wind turbine) is:
:
Wind power in an open air stream is thus ''proportional'' to the ''third power'' of the wind speed; the available power increases eightfold when the wind speed doubles.
Wind is the movement of air across the surface of the Earth, driven by areas of high and low pressure.
The global wind kinetic energy averaged approximately 1.50 MJ/m
2 over the period from 1979 to 2010, 1.31 MJ/m
2 in the Northern Hemisphere with 1.70 MJ/m
2 in the Southern Hemisphere. The atmosphere acts as a thermal engine, absorbing heat at higher temperatures, releasing heat at lower temperatures. The process is responsible for the production of wind kinetic energy at a rate of 2.46 W/m
2 thus sustaining the circulation of the atmosphere against friction.
Through
wind resource assessment Wind resource assessment is the process by which wind power developers estimate the future energy production of a wind farm. Accurate wind resource assessments are crucial to the successful development of wind farms.
History
Modern wind resource ...
, it is possible to estimate wind power potential globally,
by country
By or BY may refer to:
Places
* By, Doubs, France, a commune
* By, Norway, a village
Codes
* Belarus ISO country code
** .by, country-code top-level domain for Belarus
* Burundi FIPS Pub 10-4 and obsolete NATO digram country code
* TUI Airwa ...
or region, or for a specific site. The
Global Wind Atlas
The Global Wind Atlas is a web-based application developed to help policymakers and investors identify potential high-wind areas for wind power generation virtually anywhere in the world, and perform preliminary calculations. It provides free ...
provided by the
Technical University of Denmark
The Technical University of Denmark ( da, Danmarks Tekniske Universitet), often simply referred to as DTU, is a polytechnic university and school of engineering. It was founded in 1829 at the initiative of Hans Christian Ørsted as Denmark's fi ...
in partnership with the
World Bank
The World Bank is an international financial institution that provides loans and grants to the governments of low- and middle-income countries for the purpose of pursuing capital projects. The World Bank is the collective name for the Interna ...
provides a global assessment of wind power potential.
Unlike 'static' wind resource atlases which average estimates of wind speed and power density across multiple years, tools such as
Renewables.ninja
Renewables.ninja is a web tool developed by Imperial College London and ETH Zürich that shows the estimated amount of energy that could be generated by wind or solar farms at any location. The model has been tested by Iain Staffell who is the cod ...
provide time-varying simulations of wind speed and power output from different wind turbine models at an hourly resolution. More detailed, site-specific assessments of wind resource potential can be obtained from specialist commercial providers, and many of the larger wind developers have in-house modeling capabilities.
The total amount of economically extractable power available from the wind is considerably more than present human power use from all sources. The strength of wind varies, and an average value for a given location does not alone indicate the amount of energy a wind turbine could produce there.
To assess prospective wind power sites, a probability distribution function is often fit to the observed wind speed data. Different locations will have different wind speed distributions. The
Weibull
Weibull is a Swedish locational surname. The Weibull family share the same roots as the Danish / Norwegian noble family of Falsenbr>They originated from and were named after the village of Weiböl in Widstedts parish, Jutland, but settled in Sk ...
model closely mirrors the actual distribution of hourly/ten-minute wind speeds at many locations. The Weibull factor is often close to 2 and therefore a
Rayleigh distribution
In probability theory and statistics, the Rayleigh distribution is a continuous probability distribution for nonnegative-valued random variables. Up to rescaling, it coincides with the chi distribution with two degrees of freedom.
The distribut ...
can be used as a less accurate, but simpler model.
Wind farms
A wind farm is a group of
wind turbine
A wind turbine is a device that converts the kinetic energy of wind into electrical energy. Hundreds of thousands of large turbines, in installations known as wind farms, now generate over 650 gigawatts of power, with 60 GW added each year. ...
s in the same location. A large wind farm may consist of several hundred individual wind turbines distributed over an extended area. The land between the turbines may be used for agricultural or other purposes. For example,
Gansu Wind Farm
The Gansu Wind Farm Project or Jiuquan Wind Power Base is a group of large wind farms under construction in western Gansu province in China. The Gansu Wind Farm Project is located in desert areas near the city of Jiuquan in two localities of Gua ...
, the largest wind farm in the world, has several thousand turbines. A wind farm may also be located offshore. Almost all large wind turbines have the same design — a horizontal axis wind turbine having an upwind rotor with 3 blades, attached to a
nacelle
A nacelle ( ) is a "streamlined body, sized according to what it contains", such as an engine, fuel, or equipment on an aircraft. When attached by a pylon entirely outside the airframe, it is sometimes called a pod, in which case it is attached ...
on top of a tall tubular tower.
In a wind farm, individual turbines are interconnected with a medium voltage (often 34.5 kV) power collection system and communications network. In general, a distance of 7D (7 times the rotor diameter of the wind turbine) is set between each turbine in a fully developed wind farm. At a substation, this medium-voltage electric current is increased in voltage with a
transformer
A transformer is a passive component that transfers electrical energy from one electrical circuit to another circuit, or multiple circuits. A varying current in any coil of the transformer produces a varying magnetic flux in the transformer' ...
for connection to the high voltage
electric power transmission
Electric power transmission is the bulk movement of electrical energy from a generating site, such as a power plant, to an electrical substation. The interconnected lines that facilitate this movement form a ''transmission network''. This is ...
system.
Generator characteristics and stability
Induction generator
An induction generator or ''asynchronous generator'' is a type of alternating current (AC) electrical generator that uses the principles of induction motors to produce electric power. Induction generators operate by mechanically turning their ro ...
s are not used in current turbines. Instead, most turbines use variable speed generators combined with either a partial or full-scale power converter between the turbine generator and the collector system, which generally have more desirable properties for grid interconnection and have
low voltage ride through-capabilities.
Modern turbines use either
doubly fed electric machine Doubly-fed electric machines also slip-ring generators are electric motors or electric generators, where both the field magnet windings and armature windings are separately connected to equipment outside the machine.
By feeding adjustable frequ ...
s with partial-scale converters or squirrel-cage induction generators or synchronous generators (both permanently and electrically excited) with full-scale converters.
Black start
A black start is the process of restoring an electric power station or a part of an electric grid to operation without relying on the external electric power transmission network to recover from a total or partial shutdown.Knight, U.G. ''Power ...
is possible and is being further developed for places (such as
Iowa
Iowa () is a state in the Midwestern region of the United States, bordered by the Mississippi River to the east and the Missouri River and Big Sioux River to the west. It is bordered by six states: Wisconsin to the northeast, Illinois to the ...
) which generate most of their electricity from wind.
Transmission systems operators will supply a wind farm developer with a
grid code A grid code is a technical specification which defines the parameters a facility connected to a public electric grid has to meet to ensure safe, secure and economic proper functioning of the electric system. The facility can be an electricity gener ...
to specify the requirements for interconnection to the transmission grid. This will include the
power factor
In electrical engineering, the power factor of an AC power system is defined as the ratio of the '' real power'' absorbed by the load to the ''apparent power'' flowing in the circuit. Real power is the average of the instantaneous product of v ...
, the constancy of
frequency
Frequency is the number of occurrences of a repeating event per unit of time. It is also occasionally referred to as ''temporal frequency'' for clarity, and is distinct from ''angular frequency''. Frequency is measured in hertz (Hz) which is eq ...
, and the dynamic behaviour of the wind farm turbines during a system fault.
Offshore wind power
Offshore wind power is wind farms in large bodies of water, usually the sea. These installations can use the more frequent and powerful winds that are available in these locations and have less visual impact on the landscape than land-based projects. However, the construction and maintenance costs are considerably higher.
Siemens
Siemens AG ( ) is a German multinational conglomerate corporation and the largest industrial manufacturing company in Europe headquartered in Munich with branch offices abroad.
The principal divisions of the corporation are ''Industry'', '' ...
and
Vestas
Vestas Wind Systems A/S is a Danish manufacturer, seller, installer, and servicer of wind turbines that was founded in 1945. The company operates manufacturing plants in Denmark, Germany, the Netherlands, Taiwan, India, Italy, Romania, the Uni ...
are the leading turbine suppliers for offshore wind power.
Ørsted,
Vattenfall
Vattenfall is a Swedish multinational power company owned by the Swedish State. Beyond Sweden, the company generates power in Denmark, Finland, Germany, the Netherlands, and the United Kingdom.
The company's name is Swedish for "waterfall", and ...
, and
RWE
RWE AG is a German multinational energy company headquartered in Essen. It generates and trades electricity in Asia-Pacific, Europe and the United States. The company is Europe's most climate threatening Company, the world's number two in offsh ...
are the leading offshore operators.
[Madsen & Krogsgaard (22 November 2010]
Offshore Wind Power 2010
''BTM Consult BTM Consult is an independent consultancy company specializing in services pertaining to renewable energy commercialization. The company was founded 1989 by Per Krogsgaard and Birger Madsen. The Staff at BTM Consult have been working with wind powe ...
''. As of November 2021, the
Hornsea Wind Farm
Hornsea Wind Farm is a Round 3 wind farm which began construction in 2018. Sited in the North Sea off the east coast of England, the eventual wind farm group is planned to have a total capacity of up to 6 gigawatt (GW).
The development h ...
in the
United Kingdom
The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the continental mainland. It comprises England, Scotland, Wales and North ...
is the largest offshore wind farm in the world at 1,218
MW.
Collection and transmission network
In a
wind farm
A wind farm or wind park, also called a wind power station or wind power plant, is a group of wind turbines in the same location used Wind power, to produce electricity. Wind farms vary in size from a small number of turbines to several hundre ...
, individual turbines are interconnected with a medium voltage (usually 34.5 kV) power collection system and communications network. At a substation, this medium-voltage electric current is increased in voltage with a transformer for connection to the high voltage
electric power transmission
Electric power transmission is the bulk movement of electrical energy from a generating site, such as a power plant, to an electrical substation. The interconnected lines that facilitate this movement form a ''transmission network''. This is ...
system. A transmission line is required to bring the generated power to (often remote) markets. For an offshore station, this may require a submarine cable. Construction of a new high voltage line may be too costly for the wind resource alone, but wind sites may take advantage of lines already installed for conventional fuel generation.
Wind power resources are not always located near to high population density. As transmission lines become longer, the losses associated with power transmission increase, as modes of losses at lower lengths are exacerbated and new modes of losses are no longer negligible as the length is increased; making it harder to transport large loads over large distances.
When the transmission capacity does not meet the generation capacity, wind farms are forced to produce below their full potential or stop running altogether, in a process known as
curtailment. While this leads to potential renewable generation left untapped, it prevents possible grid overload or risk to reliable service.
[wind-power-in-maine_2013-08-04.html?pagenum=full Inadequate transmission lines keeping some Maine wind power off the grid – The Portland Press Herald / Maine Sunday Telegram]
. Pressherald.com (4 August 2013). Retrieved on 20 July 2016.
One of the biggest current challenges to wind power grid integration in some countries is the necessity of developing new transmission lines to carry power from wind farms, usually in remote lowly populated areas due to availability of wind, to high load locations, usually on the coasts where population density is higher. Any existing transmission lines in remote locations may not have been designed for the transport of large amounts of energy.
[Wald, Matthew (26 August 2008]
. ''New York Times'' In particular geographic regions, peak wind speeds may not coincide with peak demand for electrical power, whether offshore or onshore. A possible future option may be to interconnect widely dispersed geographic areas with an HVDC
super grid.
Wind power capacity and production
Growth trends
![Wind energy generation by region, OWID](https://upload.wikimedia.org/wikipedia/commons/0/0e/Wind_energy_generation_by_region%2C_OWID.svg)
In 2020, wind supplied almost 1600
TWh TWH or twh could refer to:
* Tai Dón language, a language of Vietnam, Laos, and China
* Tai Wo Hau station, Hong Kong; MTR station code
* Tennessee Walking Horse, a breed of horse
* Toronto Western Hospital, a hospital in Toronto, Canada
* Tun ...
of electricity, which was over 5% of worldwide electrical generation and about 2% of energy consumption.
With over 100
GW added during 2020, mostly
in China
IN, In or in may refer to:
Places
* India (country code IN)
* Indiana, United States (postal code IN)
* Ingolstadt, Germany (license plate code IN)
* In, Russia, a town in the Jewish Autonomous Oblast
Businesses and organizations
* Independ ...
, global installed wind power capacity reached more than 730 GW.
But to help meet the
Paris Agreement
The Paris Agreement (french: Accord de Paris), often referred to as the Paris Accords or the Paris Climate Accords, is an international treaty on climate change. Adopted in 2015, the agreement covers climate change mitigation, Climate change a ...
's goals to
limit climate change, analysts say it should expand much faster - by over 1% of electricity generation per year.
Expansion of wind power is being hindered by
fossil fuel subsidies
Fossil fuel subsidies are energy subsidies on fossil fuels. They may be tax breaks on consumption, such as a lower sales tax on natural gas for residential heating; or subsidies on production, such as tax breaks on exploration for oil. Or ...
.
The actual amount of electric power that wind can generate is calculated by multiplying the
nameplate capacity
Nameplate capacity, also known as the rated capacity, nominal capacity, installed capacity, or maximum effect, is the intended full-load sustained output of a facility such as a power station, by the
capacity factor
The net capacity factor is the unitless ratio of actual electrical energy output over a given period of time to the theoretical maximum electrical energy output over that period. The theoretical maximum energy output of a given installation is de ...
, which varies according to equipment and location. Estimates of the capacity factors for wind installations are in the range of 35% to 44%.
Capacity factor
Since wind speed is not constant, a wind farm's annual energy production is never as much as the sum of the generator nameplate ratings multiplied by the total hours in a year. The ratio of actual productivity in a year to this theoretical maximum is called the capacity factor. Online data is available for some locations, and the capacity factor can be calculated from the yearly output.
[Massachusetts Maritime Academy — Bourne, Mass](_blank)
This 660 kW wind turbine has a capacity factor of about 19%.[Wind Power in Ontario](_blank)
These wind farms have capacity factors of about 28–35%.
Unlike fueled generating plants, the capacity factor is affected by several parameters, including the variability of the wind at the site and the size of the
generator
Generator may refer to:
* Signal generator, electronic devices that generate repeating or non-repeating electronic signals
* Electric generator, a device that converts mechanical energy to electrical energy.
* Generator (circuit theory), an eleme ...
relative to the turbine's swept area. A small generator would be cheaper and achieve a higher capacity factor but would produce less
electric power
Electric power is the rate at which electrical energy is transferred by an electric circuit. The SI unit of power is the watt, one joule per second. Standard prefixes apply to watts as with other SI units: thousands, millions and billions o ...
(and thus less profit) in high winds. Conversely, a large generator would cost more but generate little extra power and, depending on the type, may
stall out at low wind speed. Thus an optimum capacity factor of around 40–50% would be aimed for.
Penetration
Wind energy penetration is the fraction of energy produced by wind compared with the total generation. Wind power's share of worldwide electricity usage in 2021 was almost 7%, up from 3.5% in 2015.
There is no generally accepted maximum level of wind penetration. The limit for a particular
grid
Grid, The Grid, or GRID may refer to:
Common usage
* Cattle grid or stock grid, a type of obstacle is used to prevent livestock from crossing the road
* Grid reference, used to define a location on a map
Arts, entertainment, and media
* News g ...
will depend on the existing generating plants, pricing mechanisms, capacity for
energy storage
Energy storage is the capture of energy produced at one time for use at a later time to reduce imbalances between energy demand and energy production.
A device that stores energy is generally called an accumulator or battery.
Energy comes in ...
, demand management, and other factors. An interconnected electric power grid will already include
reserve generating and
transmission capacity to allow for equipment failures. This reserve capacity can also serve to compensate for the varying power generation produced by wind stations. Studies have indicated that 20% of the total annual electrical energy consumption may be incorporated with minimal difficulty.
[
] These studies have been for locations with geographically dispersed wind farms, some degree of
dispatchable energy or
hydropower
Hydropower (from el, ὕδωρ, "water"), also known as water power, is the use of falling or fast-running water to Electricity generation, produce electricity or to power machines. This is achieved by energy transformation, converting the Pot ...
with storage capacity, demand management, and interconnected to a large grid area enabling the export of electric power when needed. Beyond the 20% level, there are few technical limits, but the economic implications become more significant. Electrical utilities continue to study the effects of large-scale penetration of wind generation on system stability.
A wind energy penetration figure can be specified for different duration of time but is often quoted annually. To obtain 100% from wind annually requires substantial long-term storage or substantial interconnection to other systems that may already have substantial storage. On a monthly, weekly, daily, or hourly basis—or less—wind might supply as much as or more than 100% of current use, with the rest stored, exported or curtailed. The seasonal industry might then take advantage of high wind and low usage times such as at night when wind output can exceed normal demand. Such industry might include the production of silicon, aluminum, steel, or natural gas, and hydrogen, and using future long-term storage to facilitate 100% energy from
variable renewable energy
Variable renewable energy (VRE) or intermittent renewable energy sources (IRES) are renewable energy sources that are not dispatchable due to their fluctuating nature, such as wind power and solar power, as opposed to controllable renewable ener ...
. Homes can also be programmed to accept extra electric power on demand, for example by remotely turning up water heater thermostats.
Variability
![Roscoe Wind Farm in West Texas](https://upload.wikimedia.org/wikipedia/commons/d/d4/Roscoe_Wind_Farm_in_West_Texas.jpg)
Wind power is variable, and during low wind periods, it may need to be replaced by other power sources. Transmission networks presently cope with outages of other generation plants and daily changes in electrical demand, but the variability of
intermittent power source
Variable renewable energy (VRE) or intermittent renewable energy sources (IRES) are renewable energy sources that are not dispatchable due to their fluctuating nature, such as wind power and solar power, as opposed to controllable renewable ener ...
s such as wind power is more frequent than those of conventional power generation plants which, when scheduled to be operating, may be able to deliver their nameplate capacity around 95% of the time.
Electric power generated from wind power can be highly variable at several different timescales: hourly, daily, or seasonally. Annual variation also exists but is not as significant. Because instantaneous electrical generation and consumption must remain in balance to maintain grid stability, this variability can present substantial challenges to incorporating large amounts of wind power into a grid system. Intermittency and the non-
dispatchable nature of wind energy production can raise costs for regulation, incremental
operating reserve
In electricity networks, the operating reserve is the generating capacity available to the system operator within a short interval of time to meet demand in case a generator goes down or there is another disruption to the supply. Most power sys ...
, and (at high penetration levels) could require an increase in the already existing
energy demand management
Energy demand management, also known as demand-side management (DSM) or demand-side response (DSR), is the modification of consumer demand for energy through various methods such as financial incentives and behavioral change through education.
Us ...
,
load shedding
Demand response is a change in the power consumption of an electric utility customer to better match the demand for power with the supply. Until the 21st century decrease in the cost of pumped storage and batteries electric energy could not be ...
, storage solutions, or system interconnection with
HVDC
A high-voltage direct current (HVDC) electric power transmission system (also called a power superhighway or an electrical superhighway) uses direct current (DC) for electric power transmission, in contrast with the more common alternating curren ...
cables.
Fluctuations in load and allowance for the failure of large fossil-fuel generating units require operating reserve capacity, which can be increased to compensate for the variability of wind generation.
Utility-scale batteries are often used to balance hourly and shorter timescale variation, but
car batteries
An automotive battery or car battery is a rechargeable battery that is used to start a motor vehicle. Its main purpose is to provide an electric current to the electric-powered starting motor, which in turn starts the chemically-powered intern ...
may gain ground from the mid-2020s. Wind power advocates argue that periods of low wind can be dealt with by simply restarting existing power stations that have been held in readiness, or interlinking with HVDC.
[Realisable Scenarios for a Future Electricity Supply based 100% on Renewable Energies](_blank)
Gregor Czisch, University of Kassel, Germany and Gregor Giebel, Risø National Laboratory, Technical University of Denmark
The combination of diversifying variable renewables by type and location, forecasting their variation, and integrating them with dispatchable renewables, flexible fueled generators, and demand response can create a power system that has the potential to meet power supply needs reliably. Integrating ever-higher levels of renewables is being successfully demonstrated in the real world:
Solar power
Solar power is the conversion of energy from sunlight into electricity, either directly using photovoltaics (PV) or indirectly using concentrated solar power. Photovoltaic cells convert light into an electric current using the photovoltaic e ...
tends to be complementary to wind.
[Wood, Shelby (21 January 2008]
Wind + sun join forces at Washington power plant
. ''The Oregonian''. On daily to weekly timescales,
high-pressure area
A high-pressure area, high, or anticyclone, is an area near the surface of a planet where the atmospheric pressure is greater than the pressure in the surrounding regions. Highs are middle-scale meteorological features that result from interpl ...
s tend to bring clear skies and low surface winds, whereas
low-pressure area
In meteorology, a low-pressure area, low area or low is a region where the atmospheric pressure is lower than that of surrounding locations. Low-pressure areas are commonly associated with inclement weather (such as cloudy, windy, with possible ...
s tend to be windier and cloudier. On seasonal timescales, solar energy peaks in summer, whereas in many areas wind energy is lower in summer and higher in winter.
[ This study measured up to four times as much average wind power during winter as in summer for the test site.] Thus the seasonal variation of wind and solar power tend to cancel each other somewhat.
[Kaspar, F., Borsche, M., Pfeifroth, U., Trentmann, J., Drücke, J., and Becker, P.: A climatological assessment of balancing effects and shortfall risks of photovoltaics and wind energy in Germany and Europe, Adv. Sci. Res., 16, 119–128, https://doi.org/10.5194/asr-16-119-2019 , 2019] Wind hybrid power systems
Hybrid power are combinations between different technologies to produce power.
In power engineering, the term 'hybrid' describes a combined power and energy storage system.
Examples of power producers used in hybrid power are photovoltaics, ...
are becoming more popular.
Predictability
For any particular generator, there is an 80% chance that wind output will change less than 10% in an hour and a 40% chance that it will change 10% or more in 5 hours.
In summer 2021,
wind power in the United Kingdom
The United Kingdom is the best location for wind power in Europe and one of the best in the world. By 2022, the UK had over 11 thousand wind turbines with a total installed capacity of over 25gigawatts (GW): 14 GW onshore and 11 GW offshore, t ...
fell due to the lowest winds in seventy years, In the future, smoothing peaks by producing
green hydrogen
Green hydrogen (GH2 or GH2) is hydrogen generated by renewable energy or from low-carbon power.
Green hydrogen has significantly lower carbon emissions than grey hydrogen, which is produced by steam reforming of natural gas, which makes up the b ...
may help when wind has a larger share of generation.
While the output from a single turbine can vary greatly and rapidly as local wind speeds vary, as more turbines are connected over larger and larger areas the average power output becomes less variable and more predictable.
Weather forecast
Weather forecasting is the application of science and technology to predict the conditions of the atmosphere for a given location and time. People have attempted to predict the weather informally for millennia and formally since the 19th centu ...
ing permits the electric-power network to be readied for the predictable variations in production that occur.
It is thought that the most reliable low-carbon electricity systems will include a large share of wind power.
Energy storage
Typically, conventional
hydroelectricity
Hydroelectricity, or hydroelectric power, is Electricity generation, electricity generated from hydropower (water power). Hydropower supplies one sixth of the world's electricity, almost 4500 TWh in 2020, which is more than all other Renewabl ...
complements wind power very well. When the wind is blowing strongly, nearby hydroelectric stations can temporarily hold back their water. When the wind drops they can, provided they have the generation capacity, rapidly increase production to compensate. This gives a very even overall power supply and virtually no loss of energy and uses no more water.
Alternatively, where a suitable head of water is not available,
pumped-storage hydroelectricity
Pumped-storage hydroelectricity (PSH), or pumped hydroelectric energy storage (PHES), is a type of hydroelectric energy storage used by electric power systems for load balancing. The method stores energy in the form of gravitational potential ...
or other forms of
grid energy storage
Grid energy storage (also called large-scale energy storage) is a collection of methods used for energy storage on a large scale within an electrical power grid. Electrical energy is stored during times when electricity is plentiful and inexp ...
such as
compressed air energy storage
Compressed-air energy storage (CAES) is a way to store energy for later use using compressed air. At a utility scale, energy generated during periods of low demand can be released during peak load periods.Wild, Matthew, LWind Drives Growing Use ...
and
thermal energy storage
Thermal energy storage (TES) is achieved with widely different technologies. Depending on the specific technology, it allows excess thermal energy to be stored and used hours, days, months later, at scales ranging from the individual process, ...
can store energy developed by high-wind periods and release it when needed. The type of storage needed depends on the wind penetration level – low penetration requires daily storage, and high penetration requires both short- and long-term storage – as long as a month or more. Stored energy increases the economic value of wind energy since it can be shifted to displace higher-cost generation during peak demand periods. The potential revenue from this
arbitrage
In economics and finance, arbitrage (, ) is the practice of taking advantage of a difference in prices in two or more markets; striking a combination of matching deals to capitalise on the difference, the profit being the difference between the ...
can offset the cost and losses of storage. Although pumped-storage power systems are only about 75% efficient and have high installation costs, their low running costs and ability to reduce the required electrical base-load can save both fuel and total electrical generation costs.
[The Future of Electrical Energy Storage: The economics and potential of new technologies 2 January 2009 ID RET2107622]
Fuel savings and energy payback
According to the
American Wind Energy Association
The American Wind Energy Association (AWEA) is a Washington, D.C.–based national trade association formed in 1974, representing wind power project developers, equipment suppliers, service providers, parts manufacturers, utilities, researchers, ...
, production of wind power in the United States in 2015 avoided consumption of of water and reduced emissions by 132 million metric tons, while providing US$7.3 bn in public health savings.
The energy needed to build a wind farm divided into the total output over its life,
Energy Return on Energy Invested
In energy economics and ecological energetics, energy return on investment (EROI), also sometimes called energy returned on energy invested (ERoEI), is the ratio of the amount of usable energy (the ''exergy'') delivered from a particular energy re ...
, of wind power varies, but averages about 20–25. Thus, the energy payback time is typically around a year.
Economics
![Onshore-wind-lcoe](https://upload.wikimedia.org/wikipedia/commons/b/be/Onshore-wind-lcoe.png)
Onshore wind is an inexpensive source of electric power, cheaper than coal plants and new gas plants.
According to
BusinessGreen
''Incisive Media'' is a B2B information and events business. It is based in London, United Kingdom.
History
Incisive Media is a business-to-business (B2B) information and events company founded by Tim Weller, in 1994 with the launch of ''Inves ...
, wind turbines reached
grid parity
Grid parity (or socket parity) occurs when an alternative energy source can generate power at a levelized cost of electricity (LCOE) that is less than or equal to the price of power from the electricity grid. The term is most commonly used whe ...
(the point at which the cost of wind power matches traditional sources) in some areas of Europe in the mid-2000s, and in the US around the same time. Falling prices continue to drive the Levelized cost down and it has been suggested that it has reached general grid parity in Europe in 2010, and will reach the same point in the US around 2016 due to an expected reduction in capital costs of about 12%.
["Onshore wind to reach grid parity by 2016"](_blank)
, BusinessGreen, 14 November 2011 In 2021, the CEO of
Siemens Gamesa
Siemens Gamesa Renewable Energy S.A., formerly Gamesa Corporación Tecnológica S.A. () and Grupo Auxiliar Metalúrgico S.A., is a Spanish-German wind engineering company based in Zamudio, Biscay, Spain. In Spain, the company has two other main ...
warned that increased demand for low-cost wind turbines combined with high input costs and high costs of steel result in increased pressure on the manufacturers and decreasing profit margins.
Northern Eurasia, Canada, some parts of the United States, and
Patagonia
Patagonia () refers to a geographical region that encompasses the southern end of South America, governed by Argentina and Chile. The region comprises the southern section of the Andes Mountains with lakes, fjords, temperate rainforests, and gl ...
in Argentina are the best areas for onshore wind: whereas in other parts of the world solar power, or a combination of wind and solar, tend to be cheaper.
Electric power cost and trends
![Turbine Blade Convoy Passing through Edenfield](https://upload.wikimedia.org/wikipedia/commons/c/c3/Turbine_Blade_Convoy_Passing_through_Edenfield.jpg)
Wind power is
capital intensive
Capital intensity is the amount of fixed or real capital present in relation to other factors of production, especially labor. At the level of either a production process or the aggregate economy, it may be estimated by the capital to labor ratio, ...
but has no fuel costs.
[Dolf Gielen.]
Renewable Energy Technologies: Cost Analysis Series: Wind Power
''International Renewable Energy Agency
The International Renewable Energy Agency (IRENA) is an intergovernmental organization mandated to facilitate cooperation, advance knowledge, and promote the adoption and sustainable use of renewable energy. It is the first international organis ...
'', June 2012. Quote: "wind is capital intensive, but has no fuel costs" The price of wind power is therefore much more stable than the volatile prices of fossil fuel sources. However, the estimated
average cost In economics, average cost or unit cost is equal to total cost (TC) divided by the number of units of a good produced (the output Q):
AC=\frac.
Average cost has strong implication to how firms will choose to price their commodities. Firms’ sale ...
per unit of electric power must incorporate the cost of construction of the turbine and transmission facilities, borrowed funds, return to investors (including the cost of risk), estimated annual production, and other components, averaged over the projected useful life of the equipment, which may be more than 20 years. Energy cost estimates are highly dependent on these assumptions so published cost figures can differ substantially.
The presence of wind energy, even when subsidized, can reduce costs for consumers (€5 billion/yr in Germany) by reducing the marginal price, by minimizing the use of expensive
peaking power plant
Peaking power plants, also known as peaker plants, and occasionally just "peakers", are power plants that generally run only when there is a high demand, known as peak demand, for electricity. Because they supply power only occasionally, the power ...
s.
The cost has decreased as wind turbine technology has improved. There are now longer and lighter wind turbine blades, improvements in turbine performance, and increased power generation efficiency. Also, wind project capital expenditure costs and maintenance costs have continued to decline.
In 2021, a Lazard study of unsubsidized electricity said that wind power
levelized cost of electricity
The levelized cost of electricity (LCOE), or levelized cost of energy, is a measure of the average net present cost of electricity generation for a generator over its lifetime. It is used for investment planning and to compare different methods ...
continues to fall but more slowly than before. The study estimated new wind-generated electricity cost from $26 to $50/MWh, compared to new gas power from $45 to $74/MWh. The median cost of fully deprecated existing coal power was $42/MWh, nuclear $29/MWh and gas $24/MWh. The study estimated offshore wind at around $83/MWh.
Compound annual growth rate
Compound annual growth rate (CAGR) is a business and investing specific term for the geometric progression ratio that provides a constant rate of return over the time period. CAGR is not an accounting term, but it is often used to describe some ele ...
was 4% per year from 2016 to 2021, compared to 10% per year from 2009 to 2021.
Incentives and community benefits
Turbine prices have fallen significantly in recent years due to tougher competitive conditions such as the increased use of energy auctions, and the elimination of subsidies in many markets. As of 2021,
subsidies
A subsidy or government incentive is a form of financial aid or support extended to an economic sector (business, or individual) generally with the aim of promoting economic and social policy. Although commonly extended from the government, the ter ...
are still often given to offshore wind. But they are generally no longer necessary for onshore wind in countries with even a very low carbon price such as China, provided there are no competing
fossil fuel subsidies
Fossil fuel subsidies are energy subsidies on fossil fuels. They may be tax breaks on consumption, such as a lower sales tax on natural gas for residential heating; or subsidies on production, such as tax breaks on exploration for oil. Or ...
.
Secondary market forces provide incentives for businesses to use wind-generated power, even if there is a
premium price for the electricity. For example,
socially responsible manufacturers pay utility companies a premium that goes to subsidize and build new wind power infrastructure. Companies use wind-generated power, and in return, they can claim that they are undertaking strong "green" efforts.
[The 2010 Green-e Verification Report](_blank)
Retrieved on 20 May 2009 Wind projects provide local taxes, or payments in place of taxes and strengthen the economy of rural communities by providing income to farmers with wind turbines on their land.
[American Wind Energy Association (2009]
Annual Wind Industry Report, Year Ending 2008
p. 11
The wind energy sector can also produce jobs during the construction and operating phase. Jobs include the manufacturing of wind turbines and the construction process, which includes transporting, installing, and then maintaining the turbines. An estimated 1.25 million people were employed in wind power in 2020.
Small-scale wind power
![Quietrevolution Bristol 3513051949](https://upload.wikimedia.org/wikipedia/commons/b/b6/Quietrevolution_Bristol_3513051949.jpg)
Small-scale wind power is the name given to wind generation systems with the capacity to produce up to 50 kW of electrical power.
Isolated communities, that may otherwise rely on
diesel
Diesel may refer to:
* Diesel engine, an internal combustion engine where ignition is caused by compression
* Diesel fuel, a liquid fuel used in diesel engines
* Diesel locomotive, a railway locomotive in which the prime mover is a diesel engin ...
generators, may use wind turbines as an alternative. Individuals may purchase these systems to reduce or eliminate their dependence on grid electric power for economic reasons, or to reduce their
carbon footprint
A carbon footprint is the total greenhouse gas (GHG) emissions caused by an individual, event, organization, service, place or product, expressed as carbon dioxide equivalent (CO2e). Greenhouse gases, including the carbon-containing gases carbo ...
. Wind turbines have been used for household electric power generation in conjunction with
battery
Battery most often refers to:
* Electric battery, a device that provides electrical power
* Battery (crime), a crime involving unlawful physical contact
Battery may also refer to:
Energy source
*Automotive battery, a device to provide power t ...
storage over many decades in remote areas.
Examples of small-scale wind power projects in an urban setting can be found in
New York City
New York, often called New York City or NYC, is the List of United States cities by population, most populous city in the United States. With a 2020 population of 8,804,190 distributed over , New York City is also the L ...
, where, since 2009, several building projects have capped their roofs with
Gorlov-type helical wind turbines. Although the energy they generate is small compared to the buildings' overall consumption, they help to reinforce the building's 'green' credentials in ways that "showing people your high-tech boiler" cannot, with some of the projects also receiving the direct support of the
New York State Energy Research and Development Authority
The New York State Energy Research and Development Authority (NYSERDA), established in 1935, is a New York State public-benefit corporation, located in Albany, New York, with regional offices in New York City, Buffalo, and West Valley.
NYSERDA ...
.
Grid-connected domestic wind turbines may use grid energy storage, thus replacing purchased electric power with locally produced power when available. The surplus power produced by domestic microgenerators can, in some jurisdictions, be fed into the network and sold to the utility company, producing a retail credit for the microgenerators' owners to offset their energy costs.
[Home-made energy to prop up grid](_blank)
The Times
''The Times'' is a British daily national newspaper based in London. It began in 1785 under the title ''The Daily Universal Register'', adopting its current name on 1 January 1788. ''The Times'' and its sister paper ''The Sunday Times'' (fou ...
22 June 2008 Retrieved on 10 January 2013
Off-grid system users can either adapt to intermittent power or use batteries,
photovoltaic
Photovoltaics (PV) is the conversion of light into electricity using semiconducting materials that exhibit the photovoltaic effect, a phenomenon studied in physics, photochemistry, and electrochemistry. The photovoltaic effect is commercially us ...
, or diesel systems to supplement the wind turbine. Equipment such as parking meters, traffic warning signs, street lighting, or wireless Internet gateways may be powered by a small wind turbine, possibly combined with a photovoltaic system, that charges a small battery replacing the need for a connection to the power grid.
Distributed generation
Distributed generation, also distributed energy, on-site generation (OSG), or district/decentralized energy, is electrical generation and storage performed by a variety of small, grid-connected or distribution system-connected devices referred to ...
from
renewable resource
A renewable resource, also known as a flow resource, is a natural resource which will replenish to replace the portion resource depletion, depleted by usage and consumption, either through natural reproduction or other recurring processes in a ...
s is increasing as a consequence of the increased awareness of
climate change
In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to E ...
. The electronic interfaces required to connect renewable generation units with the utility system can include additional functions, such as active filtering to enhance the power quality.
Airborne wind turbine
An airborne wind turbine is a design concept for a wind turbine with a rotor supported in the air without a tower, thus benefiting from the higher velocity and persistence of wind at high altitudes, while avoiding the expense of tower construction ...
s, such as kites, can be used in places at risk of hurricanes, as they can be taken down in advance.
Impact on environment and landscape
![Wb deichh drei kuhs](https://upload.wikimedia.org/wikipedia/commons/7/79/Wb_deichh_drei_kuhs.jpg)
The
environmental impact of electricity generation
Electric power systems consist of generation plants of different energy sources, transmission networks, and distribution lines. Each of these components can have environmental impacts at multiple stages of their development and use including in ...
from wind power is minor when compared to that of
fossil fuel power.
Wind turbines have some of the lowest
life-cycle greenhouse-gas emissions of energy sources
Greenhouse gas emissions are one of the environmental impacts of electricity generation. Measurement of life-cycle greenhouse gas emissions involves calculating the global-warming potential of energy sources through life-cycle assessment. These ...
: far less
greenhouse gas is emitted than for the average unit of electricity, so wind power helps limit climate change.
Wind power consumes no fuel, and emits no local
air pollution
Air pollution is the contamination of air due to the presence of substances in the atmosphere that are harmful to the health of humans and other living beings, or cause damage to the climate or to materials. There are many different types ...
, unlike fossil fuel power sources.
Onshore wind farms can have a significant visual impact. Due to a very low
surface power density
In physics and engineering, surface power density is power per unit area.
Applications
* The intensity of electromagnetic radiation can be expressed in W/m2. An example of such a quantity is the solar constant.
* Wind turbines are often compared ...
and spacing requirements, wind farms typically need to be spread over more land than other power stations.
Their network of turbines, access roads, transmission lines, and substations can result in "energy sprawl";
although land between the turbines and roads can still be used for agriculture.
They also need to be built away from urban areas, which can lead to "industrialization of the countryside".
[Szarka, Joseph. ''Wind Power in Europe: Politics, Business and Society''. Springer, 2007. p.176] Some wind farms are opposed for potentially spoiling protected scenic areas, archaeological landscapes and heritage sites. A report by the
Mountaineering Council of Scotland
Mountaineering Scotland is the national representative body and membership organisation for mountaineers, hillwalkers, climbers and ski tourers who live in Scotland or enjoy Scotland's mountains. With nearly 16,000 members as of 2022, it encour ...
concluded that wind farms harmed
tourism
Tourism is travel for pleasure or business; also the theory and practice of touring (disambiguation), touring, the business of attracting, accommodating, and entertaining tourists, and the business of operating tour (disambiguation), tours. Th ...
in areas known for natural landscapes and panoramic views.
Habitat loss and fragmentation are the greatest potential impacts on wildlife of onshore wind farms,
but the worldwide ecological impact is minimal.
Thousands of birds and bats, including rare species, have been killed by wind turbine blades, though wind turbines are responsible for far fewer bird deaths than fossil-fueled power stations. This can be mitigated with proper wildlife monitoring.
Many wind turbine blades are made of
fiberglass
Fiberglass (American English) or fibreglass (Commonwealth English) is a common type of fiber-reinforced plastic using glass fiber. The fibers may be randomly arranged, flattened into a sheet called a chopped strand mat, or woven into glass cloth ...
, and have a lifetime of 20 years. Blades are hollow: some blades are crushed to reduce their volume and then landfilled.
Blade end-of-life is complicated, and blades manufactured in the 2020s are more likely to be designed to be completely recyclable.
Wind turbines also generate noise. At a distance of , this may be around 45 dB, which is slightly louder than a refrigerator. At , they become inaudible. There are anecdotal reports of negative health effects on people who live very close to wind turbines. Peer-reviewed research has generally not supported these claims.
Politics
Central government
![Floatgen](https://upload.wikimedia.org/wikipedia/commons/e/e6/Floatgen.jpg)
Although wind turbines with fixed bases are a mature technology and new installations are generally no longer subsidized, floating wind turbines are a relatively new technology so some governments subsidize them, for example to use deeper waters.
Fossil fuel subsidies
Fossil fuel subsidies are energy subsidies on fossil fuels. They may be tax breaks on consumption, such as a lower sales tax on natural gas for residential heating; or subsidies on production, such as tax breaks on exploration for oil. Or ...
by some governments are slowing the growth of renewables.
Permitting of wind farms can take years and some governments are trying to speed up - the wind industry says this will help limit climate change and increase energy security - sometimes groups such as
fishers
Fisher is an archaic term for a fisherman, revived as gender-neutral.
Fisher, Fishers or The Fisher may also refer to:
Places
Australia
*Division of Fisher, an electoral district in the Australian House of Representatives, in Queensland
*Elect ...
resist this but governments say that rules protecting biodiversity will still be followed.
Public opinion
Surveys of public attitudes across
Europe
Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...
and in many other countries show strong public support for wind power.
In 2008, surveys found about 80% of EU citizens supported wind power.
Bakker et al. (2012) found in their study that residents who did not want turbines built near them suffered significantly more stress than those who "benefited economically from wind turbines".
Although wind power is a popular form of energy generation, onshore or near offshore wind farms are sometimes opposed for their impact on the landscape (especially scenic areas, heritage areas and archaeological landscapes), as well as noise, and impact on tourism.
In a 2007 survey of
wind power in Canada
Wind power has a history in Canada dating back many decades, particularly on prairie farms. As of December 2021, wind power generating capacity was approximately 14,304 megawatts (MW). Combined with 2,399 MW of solar power generating capacity, t ...
, 89% of respondents said that using renewable energy sources like wind or solar power was positive for Canada because these sources were better for the environment. Only 4 percent considered using renewable sources as negative since they could be unreliable and expensive.
Another 2007 survey concluded that wind power was the
alternative energy
Renewable energy is energy that is collected from renewable resources that are naturally replenished on a Orders of magnitude (time), human timescale. It includes sources such as Solar power, sunlight, wind power, wind, the movement of Hydropo ...
source most likely to gain public support for future development in Canada, with only 16% opposed to this type of energy. By contrast, 3 out of 4 Canadians opposed nuclear power developments.
In other cases, there is
direct community ownership of wind farms. The hundreds of thousands of people who have become involved in Germany's small and medium-sized wind farms demonstrate such support there.
A 2010 Harris Poll found strong support for wind power in Germany, other European countries, and the United States.
Public support in the United States has decreased from 75% in 2020 to 62% in 2021, with the Democrat Party supporting the use of wind energy twice as much as the Republican Party. President Biden has signed an executive order to begin building large scale wind farms.
In
China
China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...
, Shen et al. (2019) found that Chinese city-dwellers may be resistant to building wind turbines in urban areas, with a surprisingly high proportion of people citing an unfounded fear of radiation as driving their concerns. Also, the study finds that like their counterparts in OECD countries, urban Chinese respondents are sensitive to direct costs and wildlife externalities. Distributing relevant information about turbines to the public may alleviate resistance.
Community
![Wind tubines cumbria](https://upload.wikimedia.org/wikipedia/commons/c/c9/Wind_tubines_cumbria.JPG)
Many wind power companies work with local communities to reduce environmental and other concerns associated with particular wind farms.
In other cases there is
direct community ownership of wind farm projects. Appropriate government consultation, planning and approval procedures also help to minimize environmental risks.
Some may still object to wind farms
but many say their concerns should be weighed against the need to address the threats posed by
air pollution
Air pollution is the contamination of air due to the presence of substances in the atmosphere that are harmful to the health of humans and other living beings, or cause damage to the climate or to materials. There are many different types ...
,
climate change
In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to E ...
and the opinions of the broader community.
In the US, wind power projects are reported to boost local tax bases, helping to pay for schools, roads, and hospitals, and to revitalize the economies of rural communities by providing steady income to farmers and other landowners.
In the UK, both the
National Trust
The National Trust, formally the National Trust for Places of Historic Interest or Natural Beauty, is a charity and membership organisation for heritage conservation in England, Wales and Northern Ireland. In Scotland, there is a separate and ...
and the
Campaign to Protect Rural England
CPRE, The Countryside Charity, formerly known by names such as the ''Council for the Preservation of Rural England'' and the ''Council for the Protection of Rural England'', is a charity in England with over 40,000 members and supporters. Forme ...
have expressed concerns about the effects on the rural landscape caused by inappropriately sited wind turbines and wind farms.
![Whitelee panorama](https://upload.wikimedia.org/wikipedia/commons/4/46/Whitelee_panorama.JPG)
Some wind farms have become tourist attractions. The
Whitelee Wind Farm
Whitelee Wind Farm is a windfarm on the Eaglesham moor in Scotland. The main visitor centre is located in East Renfrewshire, but the majority of turbines are located in East Ayrshire and South Lanarkshire. It is the largest on-shore wind farm in ...
Visitor Centre has an exhibition room, a learning hub, a café with a viewing deck and also a shop. It is run by the
Glasgow Science Centre
Glasgow Science Centre is a visitor attraction located in the Clyde Waterfront Regeneration area on the south bank of the River Clyde in Glasgow, Scotland. Queen Elizabeth II opened Glasgow Science Centre on 5 July 2001. It is one of Scotland's m ...
.
In Denmark, a loss-of-value scheme gives people the right to claim compensation for loss of value of their property if it is caused by proximity to a wind turbine. The loss must be at least 1% of the property's value.
Despite this general support for the concept of wind power in the public at large,
local opposition often exists and has delayed or aborted a number of projects.
As well as concerns about the landscape, there are concerns that some installations can produce excessive sound and vibration levels leading to a decrease in property values. Potential broadcast-reception solutions include predictive interference modeling as a component of site selection.
A study of 50,000 home sales near wind turbines found no statistical evidence that prices were affected.
While aesthetic issues are subjective and some find wind farms pleasant and optimistic, or symbols of
energy independence
Energy independence is independence or autarky regarding energy resources, energy supply and/or energy generation by the energy industry.
Energy dependence, in general, refers to mankind's general dependence on either primary or secondary energ ...
and local prosperity, protest groups are often formed to attempt to block some wind power stations for various reasons.
[Gourlay, Simon (12 August 2008]
Wind Farms Are Not Only Beautiful, They're Absolutely Necessary
, ''The Guardian''.[Aldred, Jessica (10 December 2007]
Q&A: Wind Power
, ''The Guardian''.
Some opposition to wind farms is dismissed as
NIMBY
NIMBY (or nimby), an acronym for the phrase "not in my back yard", is a characterization of opposition by residents to proposed developments in their local area, as well as support for strict land use regulations. It carries the connotation that ...
ism, but research carried out in 2009 found that there is little evidence to support the belief that residents only object to wind farms because of a "Not in my Back Yard" attitude.
Geopolitics
Wind cannot be cut off unlike oil and gas so can contribute to
energy security
Energy security is the association between national security and the availability of natural resources for energy consumption. Access to (relatively) cheap energy has become essential to the functioning of modern economies. However, the uneven ...
.
Turbine design
Wind turbine
A wind turbine is a device that converts the kinetic energy of wind into electrical energy. Hundreds of thousands of large turbines, in installations known as wind farms, now generate over 650 gigawatts of power, with 60 GW added each year. ...
s are devices that convert the wind's
kinetic energy
In physics, the kinetic energy of an object is the energy that it possesses due to its motion.
It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its accele ...
into electrical power. The result of over a millennium of windmill development and modern engineering, today's wind turbines are manufactured in a wide range of horizontal axis and vertical axis types. The smallest turbines are used for applications such as
battery charging
A battery charger, recharger, or simply charger is a device that stores energy in a battery by running an electric current through it. The charging protocol (how much voltage or current for how long, and what to do when charging is complete) depen ...
for auxiliary power. Slightly larger turbines can be used for making small contributions to a domestic power supply while selling unused power back to the utility supplier via the electrical grid. Arrays of large turbines, known as wind farms, have become an increasingly important source of renewable energy and are used in many countries as part of a strategy to reduce their reliance on fossil fuels.
Wind turbine design is the process of defining the form and specifications of a wind turbine to extract energy from the wind.
A wind turbine installation consists of the necessary systems needed to capture the wind's energy, point the turbine into the wind, convert
mechanical rotation into
electrical power
Electric power is the rate at which electrical energy is transferred by an electric circuit. The SI unit of power is the watt, one joule per second. Standard prefixes apply to watts as with other SI units: thousands, millions and billions of ...
, and other systems to start, stop, and control the turbine.
In 1919, the German physicist
Albert Betz showed that for a hypothetical ideal wind-energy extraction machine, the fundamental laws of conservation of mass and energy allowed no more than 16/27 (59%) of the kinetic energy of the wind to be captured. This
Betz limit
Betz's law indicates the maximum power that can be extracted from the wind, independent of the design of a wind turbine in open flow. It was published in 1919 by the German physicist Albert Betz. The law is derived from the principles of conserva ...
can be approached in modern turbine designs, which may reach 70 to 80% of the theoretical Betz limit.
The
aerodynamics of a wind turbine are not straightforward. The airflow at the blades is not the same as the airflow far away from the turbine. The very nature of how energy is extracted from the air also causes air to be deflected by the turbine. This affects the objects or other turbines downstream, which is known as Wake effect. Also, the aerodynamics of a wind turbine at the rotor surface exhibit phenomena that are rarely seen in other aerodynamic fields. The shape and dimensions of the blades of the wind turbine are determined by the aerodynamic performance required to efficiently extract energy from the wind, and by the strength required to resist the forces on the blade.
In addition to the aerodynamic design of the blades, the design of a complete wind power system must also address the design of the installation's rotor hub,
nacelle
A nacelle ( ) is a "streamlined body, sized according to what it contains", such as an engine, fuel, or equipment on an aircraft. When attached by a pylon entirely outside the airframe, it is sometimes called a pod, in which case it is attached ...
, tower structure, generator, controls, and foundation.
History
![Wind turbine 1888 Charles Brush](https://upload.wikimedia.org/wikipedia/commons/5/55/Wind_turbine_1888_Charles_Brush.jpg)
Wind power has been used as long as humans have put
sails
A sail is a tensile structure—which is made from fabric or other membrane materials—that uses wind power to propel sailing craft, including sailing ships, sailboats, windsurfers, ice boats, and even sail-powered land vehicles. Sails may ...
into the wind. King Hammurabi's Codex (reign 1792 - 1750 BC) already mentioned windmills for generating mechanical energy. Wind-powered machines used to grind grain and pump water, the
windmill
A windmill is a structure that converts wind power into rotational energy using vanes called windmill sail, sails or blades, specifically to mill (grinding), mill grain (gristmills), but the term is also extended to windpumps, wind turbines, and ...
and
wind pump
A windpump is a type of windmill which is used for pumping water.
Windpumps were used to pump water since at least the 9th century in what is now Afghanistan, Iran and Pakistan. The use of wind pumps became widespread across the Muslim world an ...
, were developed in what is now
Iran
Iran, officially the Islamic Republic of Iran, and also called Persia, is a country located in Western Asia. It is bordered by Iraq and Turkey to the west, by Azerbaijan and Armenia to the northwest, by the Caspian Sea and Turkmeni ...
,
Afghanistan
Afghanistan, officially the Islamic Emirate of Afghanistan,; prs, امارت اسلامی افغانستان is a landlocked country located at the crossroads of Central Asia and South Asia. Referred to as the Heart of Asia, it is bordere ...
, and
Pakistan
Pakistan ( ur, ), officially the Islamic Republic of Pakistan ( ur, , label=none), is a country in South Asia. It is the world's List of countries and dependencies by population, fifth-most populous country, with a population of almost 24 ...
by the 9th century. Wind power was widely available and not confined to the banks of fast-flowing streams, or later, requiring sources of fuel. Wind-powered pumps drained the
polders of the Netherlands
A polder () is a low-lying tract of land that forms an artificial hydrological entity, enclosed by embankments known as dikes. The three types of polder are:
# Land reclaimed from a body of water, such as a lake or the seabed
# Flood plains s ...
, and in arid regions such as the
American mid-west
The Midwestern United States, also referred to as the Midwest or the American Midwest, is one of four census regions of the United States Census Bureau (also known as "Region 2"). It occupies the northern central part of the United States. I ...
or the
Australian outback
The Outback is a remote, vast, sparsely populated area of Australia. The Outback is more remote than the bush. While often envisaged as being arid, the Outback regions extend from the northern to southern Australian coastlines and encompass a n ...
, wind pumps provided water for livestock and steam engines.
The first windmill used for the production of electric power was built in
Scotland
Scotland (, ) is a country that is part of the United Kingdom. Covering the northern third of the island of Great Britain, mainland Scotland has a border with England to the southeast and is otherwise surrounded by the Atlantic Ocean to the ...
in July 1887 by
Prof James Blyth
Professor James Blyth MA, LLD, FRSE FRSSA (4 April 1839 – 15 May 1906) was a Scottish electrical engineer and academic at Anderson's College, now the University of Strathclyde, in Glasgow. He was a pioneer in the field of electricity ...
of
Anderson's College
The University of Strathclyde ( gd, Oilthigh Shrath Chluaidh) is a public research university located in Glasgow, Scotland. Founded in 1796 as the Andersonian Institute, it is Glasgow's second-oldest university, having received its royal chart ...
, Glasgow (the precursor of
Strathclyde University
The University of Strathclyde ( gd, Oilthigh Shrath Chluaidh) is a public research university located in Glasgow, Scotland. Founded in 1796 as the Andersonian Institute, it is Glasgow's second-oldest university, having received its royal chart ...
).
Blyth's high cloth-sailed wind turbine was installed in the garden of his holiday cottage at
Marykirk
Marykirk ( gd, Obar Luathnait) is a village in the Kincardine and Mearns area of Aberdeenshire, Scotland, next to the border with Angus at the River North Esk.
The village is approximately 6 miles ENE of Montrose at the southern end of the Ho ...
in
Kincardineshire
Kincardineshire, also known as the Mearns (from the Scottish Gaelic meaning "the Stewartry"), is a historic county, registration county and lieutenancy area on the coast of northeast Scotland. It is bounded by Aberdeenshire on the north and w ...
, and was used to charge
accumulators developed by the Frenchman
Camille Alphonse Faure
Camille Alphonse Faure (21 May 1840 – 14 September 1898) was a French chemical engineer who in 1881 significantly improved the design of the lead-acid battery, which had been invented by Gaston Planté in 1859. Faure's improvements greatly ...
, to power the lighting in the cottage,
thus making it the first house in the world to have its electric power supplied by wind power. Blyth offered the surplus electric power to the people of Marykirk for lighting the main street, however, they turned down the offer as they thought electric power was "the work of the devil."
Although he later built a wind turbine to supply emergency power to the local Lunatic Asylum, Infirmary, and Dispensary of
Montrose, the invention never really caught on as the technology was not considered to be economically viable.
Across the Atlantic, in
Cleveland, Ohio
Cleveland ( ), officially the City of Cleveland, is a city in the U.S. state of Ohio and the county seat of Cuyahoga County. Located in the northeastern part of the state, it is situated along the southern shore of Lake Erie, across the U.S. ...
, a larger and heavily engineered machine was designed and constructed in the winter of 1887–1888 by
Charles F. Brush. This was built by his engineering company at his home and operated from 1886 until 1900. The Brush wind turbine had a rotor in diameter and was mounted on an tower. Although large by today's standards, the machine was only rated at 12 kW. The connected dynamo was used either to charge a bank of batteries or to operate up to 100
incandescent light bulb
An incandescent light bulb, incandescent lamp or incandescent light globe is an electric light with a wire filament heated until it glows. The filament is enclosed in a glass bulb with a vacuum or inert gas to protect the filament from oxida ...
s, three arc lamps, and various motors in Brush's laboratory.
With the development of electric power, wind power found new applications in lighting buildings remote from centrally generated power. Throughout the 20th century parallel paths developed small wind stations suitable for farms or residences. The
1973 oil crisis
The 1973 oil crisis or first oil crisis began in October 1973 when the members of the Organization of Arab Petroleum Exporting Countries (OAPEC), led by Saudi Arabia, proclaimed an oil embargo. The embargo was targeted at nations that had supp ...
triggered the investigation in Denmark and the United States that led to larger utility-scale wind generators that could be connected to electric power grids for remote use of power. By 2008, the U.S. installed capacity had reached 25.4 gigawatts, and by 2012 the installed capacity was 60 gigawatts.
Today, wind-powered generators operate in every size range between tiny stations for battery charging at isolated residences, up to gigawatt-sized
offshore wind farms
Offshore wind power or offshore wind energy is the Wind power, generation of electricity through wind farms in bodies of water, usually at sea. There are higher wind speeds offshore than on land, so offshore farms generate more electricity per ...
that provide electric power to national electrical networks.
See also
*
100% renewable energy
100% renewable energy means getting all energy from renewable resources. The endeavor to use 100% renewable energy for electricity, heating, cooling and transport is motivated by climate change, pollution and other environmental issues, ...
*
Airborne wind turbine
An airborne wind turbine is a design concept for a wind turbine with a rotor supported in the air without a tower, thus benefiting from the higher velocity and persistence of wind at high altitudes, while avoiding the expense of tower construction ...
*
Global Wind Day
Global Wind Day or World Wind Day is a worldwide event that is held on June 15 around the world. It is organised by WindEurope and GWEC (Global Wind Energy Council).
It is a day when wind energy is celebrated, information is exchanged and adult ...
*
Hydrogen economy
The hydrogen economy is using hydrogen to decarbonize economic sectors which are hard to electrify, essentially, the "hard-to-abate" sectors such as cement, steel, long-haul transport etc. In order to phase out fossil fuels and limit climate ch ...
*
*
List of wind turbine manufacturers
This is a list of notable wind turbine manufacturers and businesses that manufacture major wind turbine components.
Small wind turbine manufacturers
* Bornay (Spain)
* Enessere (Italy)
* Hi-VAWT (Taiwan)
* quietrevolution (United Kingdom ...
*
Lists of offshore wind farms by country
The largest offshore wind power facilities are listed at List of offshore wind farms.
By country
* List of offshore wind farms in China
* List of offshore wind farms in Denmark
* List of offshore wind farms in Germany
* List of offshore wind fa ...
*
Lists of wind farms by country
Lists of wind farms include:
*List of onshore wind farms
*List of offshore wind farms
Wind farms by country
* List of wind farms in Australia
* List of wind farms in Canada
* List of wind farms in China
* List of wind farms in Denmark
* Lis ...
*
Outline of wind energy
The following outline is provided as an overview of and topical guide to wind energy:
Wind energy – the kinetic energy of air in motion, also called wind.
What type of thing is wind energy?
Wind energy can be described as all of the f ...
*
Wind resource assessment Wind resource assessment is the process by which wind power developers estimate the future energy production of a wind farm. Accurate wind resource assessments are crucial to the successful development of wind farms.
History
Modern wind resource ...
*
Wind power by country
The worldwide total cumulative installed electricity generation capacity from wind power has increased rapidly since the start of the third millennium, and as of the end of 2020, it amounts to 733 GW. Since 2010, more than half of all new w ...
Notes
References
External links
Global Wind Energy Council (GWEC)Windfrom Project Regeneration
World Wind Energy Association (WWEA)Dynamic Data Dashboardfrom the International Energy Agency
Current global map of wind power density
{{Authority control
Bright green environmentalism
Renewable energy
ja:風力