3d drawing of a wind turbine

A wind turbine is a device that converts the wind'due south kinetic free energy into electrical energy.

Wind turbines are manufactured in a wide range of vertical and horizontal centrality types. The smallest turbines are used for applications such as battery charging for auxiliary power for boats or caravans or to power traffic warning signs. Slightly larger turbines can be used for making contributions to a domestic ability supply while selling unused power dorsum to the utility supplier via the electrical grid. Arrays of big turbines, known equally wind farms, are becoming an increasingly of import source of intermittent renewable free energy and are used by many countries as part of a strategy to reduce their reliance on fossil fuels.

i History
2 Resource
3 Efficiency
4 Types
- 4.ane Horizontal axis
- four.two Vertical axis
5 Design and construction
- 5.1 Unconventional designs
- 5.2 Turbine monitoring and diagnostics
six Materials and durability
7 Current of air turbines on public display
8 Small wind turbines
9 Wind turbine spacing
10 Operability
- x.1 Maintenance
- 10.ii Repowering
- 10.3 Demolition
xi Advantages and Disadvantages
- 11.1 Advantages
- xi.two Disadvantages
12 Records
13 See also
15 Further reading

History

James Blyth'due south electricity-generating wind turbine, photographed in 1891

Current of air power was probably used in Persia (present-day Iran) almost 500–900 AD.^[i] The windwheel of Hero of Alexandria marks one of the kickoff recorded instances of current of air powering a machine in history.^[two] ^[iii] Even so, the starting time known practical wind power plants were built in Sistan, an Eastern province of Iran, from the 7th century. These "Panemone" were vertical beam windmills, which had long vertical drive shafts with rectangular blades.^[iv] Made of 6 to twelve sails covered in reed matting or textile material, these windmills were used to grind grain or depict up water, and were used in the gristmilling and sugarcane industries.^[five]

Wind power first appeared in Europe during the Eye Ages. The get-go historical records of their use in England appointment to the 11th or twelfth centuries and there are reports of German crusaders taking their windmill-making skills to Syria around 1190.^[6] Past the 14th century, Dutch windmills were in use to drain areas of the Rhine delta. Advanced wind turbines were described by Croatian inventor Fausto Veranzio. In his book Machinae Novae (1595) he described vertical centrality current of air turbines with curved or 5-shaped blades.

The start electricity-generating air current turbine was a battery charging machine installed in July 1887 by Scottish academic James Blyth to light his vacation habitation in Marykirk, Scotland.^[7] Some months after American inventor Charles F. Brush was able to build the commencement automatically operated wind turbine after consulting local Academy professors and colleagues Jacob Southward. Gibbs and Brinsley Coleberd and successfully getting the blueprints peer-reviewed for electricity product in Cleveland, Ohio.^[vii] Although Blyth's turbine was considered uneconomical in the Britain^[7] electricity generation past air current turbines was more toll effective in countries with widely scattered populations.^[vi]

In Kingdom of denmark past 1900, there were about 2500 windmills for mechanical loads such as pumps and mills, producing an estimated combined peak power of most 30 MW. The largest machines were on 24-meter (79 ft) towers with iv-bladed 23-meter (75 ft) diameter rotors. Past 1908 there were 72 wind-driven electric generators operating in the United States from five kW to 25 kW. Around the time of World War I, American windmill makers were producing 100,000 farm windmills each yr, mostly for water-pumping.^[9]

By the 1930s, wind generators for electricity were common on farms, mostly in the U.s.a. where distribution systems had not yet been installed. In this period, loftier-tensile steel was cheap, and the generators were placed atop prefabricated open steel lattice towers.

A forerunner of modern horizontal-centrality wind generators was in service at Yalta, USSR in 1931. This was a 100 kW generator on a 30-meter (98 ft) belfry, connected to the local 6.three kV distribution organisation. It was reported to take an annual capacity factor of 32 per centum, non much unlike from current wind machines.^[x]

In the autumn of 1941, the first megawatt-course wind turbine was synchronized to a utility grid in Vermont. The Smith-Putnam wind turbine simply ran for 1,100 hours earlier suffering a critical failure. The unit was not repaired, because of shortage of materials during the war.

The start utility grid-continued wind turbine to operate in the U.k. was congenital by John Chocolate-brown & Company in 1951 in the Orkney Islands.^[7] ^[11]

Despite these diverse developments, developments in fossil fuel systems almost entirely eliminated any current of air turbine systems larger than supermicro size. In the early 1970s, notwithstanding, anti-nuclear protests in Denmark spurred artisan mechanics to develop microturbines of 22 kW. Organizing owners into associations and co-operatives lead to the lobbying of the authorities and utilities and provided incentives for larger turbines throughout the 1980s and after. Local activists in Germany, nascent turbine manufacturers in Kingdom of spain, and large investors in the United states of america in the early 1990s and then lobbied for policies that stimulated the manufacture in those countries. Later companies formed in Bharat and China. As of 2012, Danish company Vestas is the world's biggest current of air-turbine manufacturer.

Resources

A quantitative measure of wind energy available at whatsoever location is called the Wind Ability Density (WPD). Information technology is a calculation of the mean annual power available per square meter of swept area of a turbine, and is tabulated for different heights above ground. Calculation of wind power density includes the effect of air current velocity and air density. Color-coded maps are prepared for a particular area described, for case, equally "Mean Annual Power Density at 50 Metres". In the United States, the results of the above calculation are included in an index developed by the National Renewable Energy Laboratory and referred to every bit "NREL Class". The larger the WPD, the higher information technology is rated past grade. Classes range from Class i (200 watts per square meter or less at fifty chiliad distance) to Form 7 (800 to 2000 watts per foursquare m). Commercial wind farms generally are sited in Class iii or college areas, although isolated points in an otherwise Class 1 expanse may exist applied to exploit.^[12]

Air current turbines are classified past the current of air speed they are designed for, from class I to class 4, with A or B referring to the turbulence.^[13]

Course	Avg Wind Speed (m/s)	Turbulence
IA	10	18%
IB	10	xvi%
IIA	8.5	18%
IIB	8.v	xvi%
IIIA	7.5	eighteen%
IIIB	7.5	sixteen%
IVA	6	18%
IVB	6	16%

Efficiency

Non all the free energy of blowing wind can be used, but some small-scale current of air turbines are designed to work at low current of air speeds.^[xiv]

Conservation of mass requires that the corporeality of air entering and exiting a turbine must be equal. Accordingly, Betz'southward constabulary gives the maximal achievable extraction of wind power by a wind turbine as 16/27 (59.3%) of the total kinetic energy of the air flowing through the turbine.^[xv]

The maximum theoretical power output of a current of air machine is thus xvi/27 times the kinetic energy of the air passing through the constructive deejay area of the auto. If the constructive area of the deejay is A, and the wind velocity v, the maximum theoretical power output P is:

P={\frac {16}{27}}{\frac {one}{2}}\rho v^{iii}A={\frac {eight}{27}}\rho five^{3}A

,

where ρ is the air density.

Equally wind is free (no fuel price), wind-to-rotor efficiency (including rotor blade friction and drag) is one of many aspects impacting the final cost of current of air ability.^[16] Further inefficiencies, such equally gearbox losses, generator and converter losses, reduce the ability delivered by a wind turbine. To protect components from undue wear, extracted power is held constant above the rated operating speed as theoretical power increases at the cube of wind speed, further reducing theoretical efficiency. In 2001, commercial utility-connected turbines deliver 75% to fourscore% of the Betz limit of ability extractable from the wind, at rated operating speed.^[17] ^[18] ^{[ needs update ]}

Efficiency can decrease slightly over fourth dimension due to wear. Assay of 3128 wind turbines older than x years in Denmark showed that half of the turbines had no decrease, while the other half saw a production decrease of ane.2% per yr.^[nineteen] Vertical turbine designs accept much lower efficiency than standard horizontal designs.^[xx]

Types

Wind turbines tin rotate about either a horizontal or a vertical centrality, the old being both older and more common.^[21] They can likewise include blades (transparent or not)^[22] or be bladeless.^[23] Vertical designs produce less ability and are less mutual.^[24]

Horizontal centrality

Horizontal-centrality current of air turbines (HAWT) have the chief rotor shaft and electric generator at the top of a tower, and must be pointed into the current of air. Small turbines are pointed by a simple wind vane, while large turbines by and large use a wind sensor coupled with a servomotor. Almost have a gearbox, which turns the boring rotation of the blades into a quicker rotation that is more suitable to drive an electrical generator.^[25]

Any solid object produces a wake behind it, leading to fatigue failures, so the turbine is usually positioned upwind of its supporting tower. Downwind machines accept been congenital, because they don't demand an additional machinery for keeping them in line with the wind. In loftier winds, the blades can also be immune to bend which reduces their swept area and thus their wind resistance. In upwind designs, turbine blades must be made stiff to preclude the blades from being pushed into the belfry past high winds. Additionally, the blades are placed a considerable distance in front of the tower and are sometimes tilted forward into the wind a small amount.

Turbines used in current of air farms for commercial production of electric ability are usually three-bladed. These accept low torque ripple, which contributes to skillful reliability. The blades are unremarkably colored white for daytime visibility by aircraft and range in length from 20 to lxxx meters (66 to 262 ft). The size and acme of turbines increment yr by year. Offshore wind turbines are congenital upward to 8MW today and have a bract length up to 80m. Usual tubular steel towers of multi megawatt turbines have a height of seventyg to 120one thousand and in extremes upwards to 160m.

The blades rotate at 10 to 22 revolutions per minute. At 22 rotations per minute the tip speed exceeds ninety meters per second (300 ft/south).^[26] ^[27] College tip speeds means more dissonance and bract erosion. A gear box is unremarkably used for stepping up the speed of the generator, although designs may likewise use directly drive of an annular generator. Some models operate at constant speed, but more free energy can exist nerveless by variable-speed turbines which use a solid-state power converter to interface to the transmission arrangement. All turbines are equipped with protective features to avoid damage at high wind speeds, by feathering the blades into the wind which ceases their rotation, supplemented by brakes.

Vertical centrality

A vertical centrality Twisted Savonius type turbine.

Vertical-axis wind turbines (or VAWTs) have the main rotor shaft bundled vertically. 1 reward of this organisation is that the turbine does not need to be pointed into the wind to exist effective, which is an reward on a site where the wind management is highly variable. It is besides an advantage when the turbine is integrated into a building because it is inherently less steerable. Also, the generator and gearbox can be placed near the ground, using a directly drive from the rotor assembly to the basis-based gearbox, improving accessibility for maintenance. However, these designs produce much less free energy averaged over time, which is a major drawback.^[24] ^[28]

The key disadvantages include the relatively low rotational speed with the consequential higher torque and hence higher toll of the bulldoze train, the inherently lower power coefficient, the 360-degree rotation of the aerofoil within the air current catamenia during each cycle and hence the highly dynamic loading on the blade, the pulsating torque generated past some rotor designs on the drive train, and the difficulty of modelling the wind menstruum accurately and hence the challenges of analysing and designing the rotor prior to fabricating a prototype.^[29]

When a turbine is mounted on a rooftop the building generally redirects wind over the roof and this tin double the current of air speed at the turbine. If the peak of a rooftop mounted turbine tower is approximately 50% of the building height it is most the optimum for maximum wind energy and minimum wind turbulence. Wind speeds within the congenital environment are by and large much lower than at exposed rural sites,^[30] ^[31] noise may exist a business organization and an existing structure may not fairly resist the boosted stress.

Subtypes of the vertical axis blueprint include:

Darrieus air current turbine: "Eggbeater" turbines, or Darrieus turbines, were named after the French inventor, Georges Darrieus.^[32] They have good efficiency, but produce big torque ripple and cyclical stress on the tower, which contributes to poor reliability. They also mostly require some external power source, or an additional Savonius rotor to start turning, because the starting torque is very low. The torque ripple is reduced by using three or more blades which results in greater solidity of the rotor. Solidity is measured by blade expanse divided past the rotor area. Newer Darrieus type turbines are non held up by guy-wires simply have an external superstructure connected to the meridian begetting.^[33]
Giromill: A subtype of Darrieus turbine with direct, as opposed to curved, blades. The cycloturbine variety has variable pitch to reduce the torque pulsation and is self-starting.^[34] The advantages of variable pitch are: high starting torque; a wide, relatively flat torque curve; a higher coefficient of performance; more efficient operation in turbulent winds; and a lower blade speed ratio which lowers blade angle stresses. Directly, V, or curved blades may be used.^[35]
Savonius air current turbine: These are drag-type devices with two (or more) scoops that are used in anemometers, Flettner vents (commonly seen on bus and van roofs), and in some high-reliability low-efficiency ability turbines. They are e'er self-starting if there are at to the lowest degree three scoops.
Twisted Savonius: Twisted Savonius is a modified savonius, with long helical scoops to provide smoothen torque. This is often used every bit a rooftop windturbine and has even been adapted for ships.^[36]

Another type of vertical axis is the Parallel turbine, which is similar to the crossflow fan or centrifugal fan. Information technology uses the footing result. Vertical centrality turbines of this type have been tried for many years: a unit producing 10 kW was built by Israeli wind pioneer Bruce Brill in the 1980s.^[37] ^{[ unreliable source? ]}

Floating wind turbines

In July 2022 work installing an experimental floating wind farm known as Hywind at Peterhead began. The turbines bladder on a sealed vase-like tube 78 metres deep which are filled with atomic number 26 ore to weight the structures and keep them upright in the water. The current of air farm is expected to supply power to 20,000 homes. Manufactured by Statoil, the floating turbines can be located in water upward to a kilometre deep.^[38]

Pattern and construction

Wind turbines are designed, using a range of figurer modelling techniques,^[39] to exploit the current of air energy that exists at a location. For case, Aerodynamic modeling is used to make up one's mind the optimum belfry top, control systems, number of blades and blade shape.

Air current turbines convert wind free energy to electricity for distribution. Conventional horizontal axis turbines can be divided into 3 components:

The rotor component, which is approximately xx% of the current of air turbine cost, includes the blades for converting wind energy to low speed rotational energy.
The generator component, which is approximately 34% of the air current turbine cost, includes the electrical generator,^[40] ^[41] the control electronics, and virtually likely a gearbox (e.g. planetary gearbox),^[42] adjustable-speed bulldoze or continuously variable transmission^[43] component for converting the low speed incoming rotation to high speed rotation suitable for generating electricity.
The structural support component, which is approximately fifteen% of the air current turbine cost, includes the belfry and rotor yaw mechanism.^[44]

A 1.5 MW wind turbine of a type often seen in the Usa has a tower 80 meters (260 ft) high. The rotor assembly (blades and hub) weighs 22,000 kilograms (48,000 lb). The nacelle, which contains the generator component, weighs 52,000 kilograms (115,000 lb). The concrete base for the belfry is synthetic using 26,000 kilograms (58,000 lb) of reinforcing steel and contains 190 cubic meters (250 cu yd) of concrete. The base is fifteen meters (fifty ft) in diameter and 2.4 meters (8 ft) thick well-nigh the center.^[45]

Amid all renewable energy systems wind turbines take the highest effective intensity of power-harvesting surface^[46] because turbine blades not but harvest wind power, simply too concentrate information technology.^[47] ^{[ dubious – discuss ]}

Unconventional designs

An E-66 current of air turbine in the Windpark Holtriem, Germany, has an observation deck for visitors. Another turbine of the aforementioned blazon with an observation deck is located in Swaffham, England. Airborne wind turbine designs have been proposed and developed for many years simply have yet to produce meaning amounts of free energy. In principle, wind turbines may besides exist used in conjunction with a large vertical solar updraft tower to extract the energy due to air heated by the sun.

Air current turbines which utilise the Magnus upshot have been developed.^[48]

A ram air turbine (RAT) is a special kind of pocket-size turbine that is fitted to some aircraft. When deployed, the RAT is spun by the airstream going past the shipping and can provide power for the virtually essential systems if in that location is a loss of all on-lath electrical ability,^[49] as in the case of the "Gimli Glider".

The 2-bladed SCD 6MW offshore turbine designed by aerodyn Energiesysteme and built by MingYang Current of air Ability has a helideck for helicopters on top of its nacelle. The prototype was erected in 2022 in Rudong, China.

Turbine monitoring and diagnostics

Due to information transmission problems, structural health monitoring of wind turbines is usually performed using several accelerometers and strain gages attached to the nacelle to monitor the gearbox and equipments. Currently, digital paradigm correlation and stereophotogrammetry are used to measure dynamics of air current turbine blades. These methods commonly measure displacement and strain to identify location of defects. Dynamic characteristics of non-rotating air current turbines have been measured using digital image correlation and photogrammetry.^[50] Three dimensional point tracking has also been used to measure rotating dynamics of wind turbines.^[51]

Materials and immovability

Materials that are typically used for the rotor blades in wind turbines are composites, as they tend to have a loftier stiffness, high strength, high fatigue resistance, and depression weight.^[52] Typical resins used for these composites include polyester and epoxy, while glass and carbon fibers accept been used for the reinforcing material.^[53] Construction may utilize manual layup techniques or composite resin injection molding. Equally the price of glass fibers is just about i 10th the cost of carbon fiber, drinking glass fiber is still dominant.

Equally competition in the wind market increases, companies are seeking ways to draw greater efficiency from their designs. One of the predominant ways wind turbines take gained performance is past increasing rotor diameters, and thus blade length. Retrofitting current turbines with larger blades mitigates the demand and risks associated with a system-level redesign. By incorporating carbon fiber into parts of existing blade systems, manufacturers may increase the length of the blades without increasing their overall weight. For instance, the spar cap, a structural element of a turbine blade, commonly experiences high tensile loading, making it an ideal candidate to utilize the enhanced tensile properties of carbon cobweb in comparison to glass fiber.^[54] College stiffness and lower density translates to thinner, lighter blades offering equivalent functioning. In a 10-MW turbine—which will go more common in offshore systems by 2021—blade lengths may reach over 100 1000 and counterbalance upwardly to l metric tons when fabricated out of glass fiber. A switch to carbon cobweb in the structural spar of the blade yields weight savings of xx to thirty percent, or approximately 15 metric tons.^[55] The compressive properties of carbon fiber practice not differ significantly from those of drinking glass fiber. It is therefore economical to replace drinking glass fiber components under pinch with carbon fiber components.

While the material cost is significantly college for all-drinking glass fiber blades than for hybrid drinking glass/carbon fiber blades, at that place is a potential for tremendous savings in manufacturing costs when labor price is considered. Utilizing carbon cobweb enables for simpler designs that use less raw material. The chief manufacturing process in bract fabrication is the layering of plies. By reducing the number of layers of plies, as is enabled by thinner blade design, the cost of labor may exist decreased, and in some cases, equate to the cost of labor for glass cobweb blades.^[56]

Materials for wind turbine parts other than the rotor blades (including the rotor hub, gearbox, frame, and tower) are largely composed of steel. Modern turbines uses a couple of tonnes of copper for generators, cables and such.^[57] Smaller wind turbines have begun incorporating more aluminum based alloys into these components in an effort to brand the turbines more than lightweight and efficient, and may continue to exist used increasingly if fatigue and strength properties can be improved. Prestressed concrete has been increasingly used for the fabric of the tower, but still, requires much reinforcing steel to meet the strength requirement of the turbine. Additionally, step-up gearboxes are being increasingly replaced with variable speed generators, increasing the need for magnetic materials in wind turbines.,^[52] In item, this would crave an increased supply of the rare earth metallic neodymium. Reliance on rare earth minerals for components has risked expense and price volatility as Red china has been principal producer of rare earth minerals (96% in 2009) and had been reducing its export quotas of these materials.^[58] In recent years, however, other producers take increased production of rare earth minerals and China has removed its reduced consign quota on rare earths leading to an increased supply and decreased toll of rare earth minerals, increasing the viability of the implementation of variable speed generators in wind turbines on a large scale.^[59]

Wind turbines on public display

A few localities have exploited the attending-getting nature of current of air turbines by placing them on public display, either with visitor centers effectually their bases, or with viewing areas further away.^[60] The wind turbines are generally of conventional horizontal-axis, three-bladed design, and generate ability to feed electric grids, but they also serve the unconventional roles of engineering science demonstration, public relations, and teaching.

Pocket-size wind turbines

Small-scale air current turbines may exist used for a diverseness of applications including on- or off-filigree residences, telecom towers, offshore platforms, rural schools and clinics, remote monitoring and other purposes that require free energy where at that place is no electric filigree, or where the grid is unstable. Small wind turbines may be every bit small-scale as a fifty-watt generator for boat or caravan use. Hybrid solar and wind powered units are increasingly being used for traffic signage, especially in rural locations, as they avoid the need to lay long cables from the nearest mains connection betoken.^[61] The U.South. Department of Energy'due south National Renewable Energy Laboratory (NREL) defines pocket-size wind turbines as those smaller than or equal to 100 kilowatts.^[62] Small units ofttimes have straight bulldoze generators, direct current output, aeroelastic blades, lifetime bearings and utilize a vane to point into the wind.

Larger, more than costly turbines generally have geared power trains, alternating current output, flaps and are actively pointed into the wind. Direct drive generators and aeroelastic blades for large wind turbines are being researched.

Wind turbine spacing

On most horizontal windturbine farms, a spacing of about 6–10 times the rotor diameter is oft upheld. Withal, for big air current farms distances of near 15 rotor diameters should exist more economically optimal, taking into account typical air current turbine and land costs. This conclusion has been reached past research^[63] conducted by Charles Meneveau of the Johns Hopkins University,^[64] and Johan Meyers of Leuven University in Belgium, based on calculator simulations^[65] that take into business relationship the detailed interactions among wind turbines (wakes) every bit well as with the entire turbulent atmospheric boundary layer. Moreover, recent enquiry by John Dabiri of Caltech suggests that vertical wind turbines may be placed much more than closely together and so long as an alternate pattern of rotation is created allowing blades of neighbouring turbines to move in the same direction as they arroyo i another.^[66]

Operability

Maintenance

Air current turbines need regular maintenance to stay reliable and available, reaching 98%.^[67] ^[68]

Modern turbines usually accept a small onboard crane for hoisting maintenance tools and minor components. However, big heavy components like generator, gearbox, blades and so on are rarely replaced and a heavy elevator external crane is needed in those cases. If the turbine has a difficult access road, a containerized crane can be lifted up by the internal crane to provide heavier lifting.^[69]

Repowering

Installation of new current of air turbines can be controversial. An alternative is repowering, where existing air current turbines are replaced with bigger, more powerful ones, sometimes in smaller numbers while keeping or increasing capacity.

Demolition

Older turbines were in some early cases not required to exist removed when reaching the end of their life. Some still stand, waiting to be recycled or repowered.^[seventy] ^[71]

A demolition industry develops to recycle offshore turbines at a price of DKK ii–iv meg per MW, to be guaranteed by the owner.^[72]

Advantages and Disadvantages

Advantages

Wind turbines are mostly inexpensive. They will price between ii and six cents per kilowatt hour, which is one of the lowest-priced renewable free energy sources in today's earth.^[73] And as technology needed for wind turbines continues to meliorate, the prices will decrease besides. In add-on, there is no competitive market for wind free energy, as it does not cost money to get ahold of wind.^[73] The main cost of air current turbines are the installation process. The average cost is between $48,000 and $65,000 to install. Even so, the energy harvested from the turbine will offset the installation toll, too every bit provide virtually complimentary energy for years after.^[74]

Wind turbines provide a clean energy source, emitting no greenhouse gases and no waste matter. Over one,500 tons of carbon dioxide per year can exist eliminated by using a i megawatt turbine instead of i megawatt of energy from a fossil fuel.^[75] Beingness environmentally friendly and green is a large advantage of wind turbines.

Wind turbines are also quite efficient. Wind farms tin generate between 17 and 39 times every bit much power equally they swallow, and in the United States alone, wind turbines have produced about xvi billion kilowatt-hours of energy per year.^[75]

Disadvantages

Wind turbines can be very large, reaching over 140 metres (460 ft) alpine and with blades 55 metres (lx yd) long,^[76] and people have oftentimes complained about their visual affect.

Environmental affect of wind power includes effect on wildlife. Thousands of birds, including rare species, have been killed by the blades of current of air turbines,^[77] though wind turbines contribute relatively insignificantly to anthropogenic avian mortality. For every bird killed past a wind turbine in the Usa, most 500,000 are killed by each of feral cats and buildings.^[78]. In comparison, conventional coal fired generators contribute significantly more to bird mortality, by incineration when caught in updrafts of smoke stacks and past poisoning with emissions byproducts (including particulates and heavy metals downwind of flue gases). Further, marine life is afflicted by water intakes of steam turbine cooling towers (heat exchangers) for nuclear and fossil fuel generators, by coal dust deposits in marine ecosystems (e.chiliad. damaging Australia's Slap-up Barrier Reef) and by water acidification from combustion monoxides.

Energy harnessed by wind turbines is intermittent, and is not a "dispatchable" source of ability; its availability is based on whether the wind is bravado, not whether electricity is needed. Turbines can be placed on ridges or bluffs to maximize the access of current of air they accept, merely this also limits the locations where they tin exist placed.^[73] In this manner, wind energy is non a peculiarly reliable source of energy. Withal, it can form part of the free energy mix, which likewise includes ability from other sources. Notably, the relative available output from wind and solar sources is frequently inversely proportional (balancing). Engineering science is also being developed to store excess energy, which can then make up for any deficits in supplies.

Records

Largest chapters conventional drive: The Vestas V164 has a rated capacity of viii MW,^[79] later upgraded to ix MW.^[80] The wind turbine has an overall height of 220 yard (722 ft), a diameter of 164 g (538 ft), is for offshore use, and is the world's largest-chapters wind turbine since its introduction in 2014. The conventional drive train consist of a main gearbox and a medium speed PM generator. Prototype installed in 2022 at the National Exam Centre Denmark nearby Østerild. Series production began end of 2015.
Largest capacity direct drive: The Enercon E-126 with 7.58 MW and 127 m rotor diameter is the largest direct bulldoze turbine. It's only for onshore use. The turbine has parted rotor blades with 2 sections for send. In July 2016, Siemens upgraded its vii to eight MW.^[81]
Largest vertical-axis: Le Nordais wind farm in Cap-Chat, Quebec has a vertical axis wind turbine (VAWT) named Éole, which is the earth'due south largest at 110 k.^[82] It has a nameplate chapters of iii.8 MW.^[83]
Largest 1-bladed turbine: Riva Calzoni M33 was a single-bladed wind turbine with 350 kW, designed and built In Bologna in 1993.^{[ citation needed ]}
Largest 2-bladed turbine: The biggest ii-bladed turbine is built by Mingyang Air current Power in 2013. Information technology is a SCD6.5MW offshore downwind turbine, designed by aerodyn Energiesysteme.^[84] ^[85] ^[86]
Largest swept area: The turbine with the largest swept area is the Samsung S7.0–171, with a diameter of 171 m, giving a total sweep of 22966 m².
Tallest: A Nordex 3.iii MW was installed in July 2016. It has a full height of 230m, and a hub height of 164m on 100m concrete tower lesser with steel tubes on top (hybrid belfry).^[87]; Vestas V164 was the tallest current of air turbine, continuing in Østerild, Denmark, 220 meters tall, constructed in 2014. It has a steel tube belfry.
Highest tower: Fuhrländer installed a 2.5MW turbine on a 160m lattice belfry in 2003 (run into Fuhrländer Wind Turbine Laasow and Nowy Tomyśl Wind Turbines).
Nearly rotors: Lagerwey has build Four-in-1, a multi rotor air current turbine with one tower and four rotors near Maasvlakte.^{[ citation needed ]} In Apr 2016, Vestas installed a 900 kW quadrotor test wind turbine at Risø, made from four recycled 225 kW V29 turbines.^[88] ^[89] ^[90]
Nearly productive: 4 turbines at Rønland Offshore Current of air Farm in Denmark share the record for the nearly productive air current turbines, with each having generated 63.two GWh past June 2010.^[91]
Highest-situated: Since 2013 the world's highest-situated wind turbine was made and installed by WindAid and is located at the base of the Pastoruri Glacier in Peru at 4,877 meters (xvi,001 ft) above sea level.^[92] The site uses the WindAid 2.5 kW wind generator to supply power to a minor rural community of micro entrepreneurs who cater to the tourists who come to the Pastoruri glacier.^[93]
Largest floating wind turbine: The world'due south largest—and likewise the commencement operational deep-water large-capacity—floating wind turbine is the 2.3 MW Hywind currently operating 10 kilometers (6.2 mi) offshore in 220-meter-deep water, southwest of Karmøy, Kingdom of norway. The turbine began operating in September 2009 and utilizes a Siemens two.three MW turbine.^[94] ^[95]