airborne wind turbine
{{Short description|High-altitude flying turbine for generating electricity}}
An airborne wind turbine is a design concept for a wind turbine with a rotor supported in the air without a tower,{{cite news |title=Flights of fancy: airborne wind turbines |work=Institute of Physics, Environmental Research Web |first=Dave |last=Elliot |url=http://blog.environmentalresearchweb.org/2014/04/12/flights-of-fancy-airborne-wind-turbines/ |date=2014-04-12 |access-date=2014-04-17 |archive-url=https://web.archive.org/web/20140419011953/http://blog.environmentalresearchweb.org/2014/04/12/flights-of-fancy-airborne-wind-turbines/ |archive-date=2014-04-19 |url-status=dead }} thus benefiting from the higher velocity and persistence of wind at high altitudes, while avoiding the expense of tower construction,{{Cite magazine |first=Michael |last=Specter |title=Inherit the Wind |magazine=The New Yorker |date=May 20, 2013 |url=http://www.newyorker.com/reporting/2013/05/20/130520fa_fact_specter}} or the need for slip rings or yaw mechanism. An electrical generator may be on the ground or airborne. Challenges include safely suspending and maintaining turbines hundreds of meters off the ground in high winds and storms, transferring the harvested and/or generated power back to earth, and interference with aviation.{{cite news |title=High-Altitude Wind Energy: Huge Potential — And Hurdles |work=Environment 360 |first=David |last=Levitan |url=http://e360.yale.edu/feature/high_altitude_wind_energy_huge_potential_and_hurdles/2576/|quote=How do you safely suspend airborne turbines hundreds or thousands of feet off the ground? How do you keep them aloft for long periods of time in high winds without having to perform frequent, costly maintenance? And what about interference with aviation? |date=2012-09-24}}
Airborne wind turbines may operate in low or high altitudes; they are part of a wider class of Airborne Wind Energy Systems (AWES) addressed by high-altitude wind power and crosswind kite power. When the generator is on the ground,{{cite web|url=http://www.energykitesystems.net/0/methods/index.html|title=Airborne Wind Energy Generation Systems|website=www.energykitesystems.net}} then the tethered aircraft need not carry the generator mass or have a conductive tether. When the generator is aloft, then a conductive tether would be used to transmit energy to the ground or used aloft or beamed to receivers using microwave or laser. Kites and helicopters come down when there is insufficient wind; kytoons and blimps may resolve the matter with other disadvantages. Also, bad weather such as lightning or thunderstorms, could temporarily suspend use of the machines, probably requiring them to be brought back down to the ground and covered. Some schemes require a long power cable and, if the turbine is high enough, a prohibited airspace zone. As of 2022, few commercial airborne wind turbines are in regular operation.{{Cite web |last=Jones |first=Nicola |title=The kites seeking the world's surest winds |url=https://www.bbc.com/future/article/20220309-the-kites-flying-to-harness-the-worlds-strongest-winds |access-date=2022-04-02 |website=BBC |date=9 March 2022 |language=en}}
Aerodynamic variety
An aerodynamic airborne wind power system relies on the wind for support.
File:Crosswind kite power station with fast motion transfer having two wings offshore.jpg In one class, the generator is aloft; an aerodynamic structure resembling a kite, tethered to the ground, extracts wind energy by supporting a wind turbine. In another class of devices, such as crosswind kite power, generators are on the ground; one or more airfoils or kites exert force on a tether, which is converted to electrical energy. An airborne turbine requires conductors in the tether or some other apparatus to transmit power to the ground. Systems that rely on a winch can instead place the weight of the generator at ground level, and the tethers need not conduct electricity.
File:Principle of kite energy.png]
Aerodynamic wind energy systems have been a subject of research interest since at least 1980.M. Loyd, [http://homes.esat.kuleuven.be/~highwind/wp-content/uploads/2011/07/Loyd1980.pdf "Crosswind Kite Power"], J. Energy, vol. 4, no. 3, pp. 106–111, 1980 Multiple proposals have been put forth but no commercial products are available.{{cite news |title=Giant kites to tap power of the high wind |url=https://www.theguardian.com/environment/2008/aug/03/renewableenergy.energy |first=Alok |last=Jha |work=The Guardian |date=3 August 2008}}{{cite web|url=http://www2.me.wpi.edu/wpi-kites/index.php/Main_Page |title=Welcome to the WPI Kite Power Wiki |access-date=2008-05-05 |url-status=bot: unknown |archive-url=https://web.archive.org/web/20110720120731/http://www2.me.wpi.edu/wpi-kites/index.php/Main_Page |archive-date=2011-07-20 }}
Other projects for airborne wind energy systems include:
- Ampyx Power
- Kitepower
- KiteGenCanale, Massimo, Lorenzo Fagiano, Mario Milanese, and Massimo Ippolito. KiteGen project: control as key technology for a quantum leap in wind energy generators, In 2007 American Control Conference, pp. 3522-3528. IEEE, 2007. https://doi.org/10.1109/ACC.2007.4282697
- Rotokite{{cite web|url=http://xercesblue.org/www_xercesblue_org_file/rotokite_ita.pdf|title=Rotokite|access-date=2011-02-12|archive-date=2016-10-26|archive-url=https://web.archive.org/web/20161026205423/http://xercesblue.org/www_xercesblue_org_file/rotokite_ita.pdf|url-status=dead}}
- HAWE System{{cite web|url=http://www.omnidea.net/site/index.php/research/wind-energy|title=FP7|last=pedro|website=www.omnidea.net|access-date=2015-02-26|archive-url=https://web.archive.org/web/20150226132135/http://www.omnidea.net/site/index.php/research/wind-energy|archive-date=2015-02-26|url-status=dead}}
- SkySails{{cite web|url=http://www.skysails.info/english/power/power-system/|title=SkySails GmbH - Compelling Technology|website=www.skysails.info|access-date=2011-10-22|archive-url=https://web.archive.org/web/20110928145507/http://www.skysails.info/english/power/power-system/|archive-date=2011-09-28|url-status=dead}}
- X-Wind technology{{cite web|url=http://www.x-wind.de/index.php/en/|title=NTS X-Wind|website=www.x-wind.de}}
- Makani Power crosswind hybrid kite system{{cite web|url=https://www.bloomberg.com/news/articles/2013-05-22/inside-googles-secret-lab|title=Inside Google's Secret Lab|first=Brad |last=Stone |date=28 May 2013|access-date=3 April 2018|publisher=Bloomberg}}
- Windswept and Interesting Kite Turbine Ring to Ring Torque Transfer{{cite web|url=http://www.windswept-and-interesting.co.uk|title=Main - Windswept and Interesting|website=www.windswept-and-interesting.co.uk}}
- Kitemill{{cite web|url= http://www.tu.no/artikler/da-finansieringsplan-a-og-b-rok-fridde-det-norske-vindkraftselskapet-kitemill-til-folket/367423 |title=77 folkeinvestorer skal holde det svevende, norske kraftverket i himmelen hele døgnet, hele året |trans-title=77 public investors will keep the floating Norwegian power plant in the sky around the clock, all year round |work=Teknisk Ukeblad|date=11 January 2017|access-date=11 January 2017}}
Aerostat variety
An aerostat-type wind power system relies at least in part on buoyancy to support the wind-collecting elements. Aerostats vary in their designs and resulting lift-to-drag ratio; the kiting effect of higher lift-over-drag shapes for the aerostat can effectively keep an airborne turbine aloft; a variety of such kiting balloons were made famous in the kytoon by Domina Jalbert.
Balloons can be incorporated to keep systems up without wind, but balloons leak slowly and have to be resupplied with lifting gas, possibly patched as well. Very large, sun-heated balloons may solve the helium or hydrogen leakage problems.
An Ontario based company called Magenn{{cite web|url=http://www.thewallnut.eu/2011/11/15/magenn-power/|title="Magenn Air Rotor System" |access-date=2012-07-09|archive-url=https://web.archive.org/web/20120329204901/http://www.thewallnut.eu/2011/11/15/magenn-power/|archive-date=2012-03-29|url-status=dead}} was developing a turbine called the Magenn Air Rotor System (MARS).{{cite web|url=http://latesttechnology-world.blogspot.com/2013/07/magenn-air-rotor-system-mars_18.html|title=Technical World : MAGENN AIR ROTOR SYSTEM (M.A.R.S.)|first=Moses Dhilip|last=Kumar|date=18 July 2013}} A future {{convert|1000|ft|m|adj=on}}-wide MARS system would use a horizontal rotor in a helium suspended apparatus which is tethered to a transformer on the ground. Magenn claims that their technology provides high torque, low starting speeds, and superior overall efficiency thanks to its ability to deploy higher in comparison to non-aerial solutions.{{cite web
|title = Magenn Power Inc. corporate website
|url = http://www.magenn.com
|access-date = December 14, 2008
|archive-url = https://web.archive.org/web/20081211041521/http://www.magenn.com/
|archive-date = 11 December 2008
|url-status = dead
}} The first prototypes were built by TCOM{{who|date=July 2012}} in April 2008. No production units have been delivered.{{cite web
|url=http://www.dailyadvance.com/news/content/news/stories/2008/04/03/0403turbineDM.html?cxtype=rss&cxsvc=7&cxcat=7
|title=Airborne turbine tested at TCOM; Magenn: MARS makes wind power mobile
|first=Diana
|last=Mazzella
|date=2008-04-03
|access-date=2008-11-23
|publisher=The Daily Advance
|archive-url=https://web.archive.org/web/20100131205017/http://www.dailyadvance.com/news/content/news/stories/2008/04/03/0403turbineDM.html?cxtype=rss&cxsvc=7&cxcat=7
|archive-date=2010-01-31
|url-status=dead
}}
Boston-based Altaeros Energies uses a helium-filled balloon shroud to lift a wind turbine into the air, transferring the resultant power down to a base station through the same cables used to control the shroud. A 35-foot prototype using a standard Skystream 2.5kW 3.7m wind turbine was flown and tested in 2012. In fall 2013, Altaeros was at work on its first commercial-scale demonstration in Alaska.{{Cite web |last=McGonegal |first=Joe |date=2013-09-04 |title=Two Alums Dream of Tethered Aerostat Wind Farms |url=http://alum.mit.edu/pages/sliceofmit/2013/09/04/two-alums-dreaming-of-tethered-aerostat-wind-farms/ |archive-url=https://web.archive.org/web/20130907215210/http://alum.mit.edu/pages/sliceofmit/2013/09/04/two-alums-dreaming-of-tethered-aerostat-wind-farms/ |archive-date=2013-09-07 |publisher=Slice of MIT}} Retrieved 2013-09-05.{{Cite web |last=Cardwell |first=Diane |date=2014-03-21 |title=Wind Industry's New Technologies Are Helping It Compete on Price |url=https://www.nytimes.com/2014/03/21/business/energy-environment/wind-industrys-new-technologies-are-helping-it-compete-on-price.html |work=New York Times}}
Another concept, released in 2023, proposed a helium-filled balloon with attached sails, which create pressure and drive the rotation of the system around its horizontal axis. The kinetic energy is transferred to a generator on the ground through ropes in circular motion.{{Citation |last=Michailidis |first=Giannis |title=High-Altitude-Wind-Turbine-Concept |date=2023-01-09 |url=https://github.com/John-Mich/High-Altitude-Wind-Turbine-Concept |access-date=2023-02-22}}
See also
{{Portal|Energy}}
References
{{Reflist|30em}}
Bibliography
- Vance, E. Wind power: High hopes. Nature 460, 564–566 (2009). https://doi.org/10.1038/460564a
- {{Cite journal |last=Houska |first=Boris |last2=Diehl |first2=Moritz |date=5 July 2007 |title=Optimal control for power generating kites |journal=2007 European Control Conference (ECC) |pages=3560–3567 |doi=10.23919/ECC.2007.7068861}}
External links
- Kitemill - Taking windpower to new heights
- [http://energykitesystems.net/ Energy Kite Systems]
- [https://web.archive.org/web/20140502131742/http://www.awelabs.com/why-airborne-wind-energy/ Why Airborne Wind Energy] Airborne Wind Energy Labs
- {{Cite magazine |url=https://www.wired.com/science/discoveries/news/2006/10/71908 |magazine=Wired |date=October 10, 2006 |title=Generating Power From Kites}}
- {{cite journal | last=Vance | first=Erik | title=Wind power: High hopes | journal=Nature | volume=460 | issue=7255 | year=2009 | doi=10.1038/460564a | pages=564–566| doi-access=free }}
- {{Cite news |url=https://github.com/John-Mich/High-Altitude-Wind-Turbine-Concept |title=An open source High-Altitude-Wind-Turbine on GitHub |work=}}
{{Wind power}}
{{emerging technologies|energy=yes}}
{{Authority control}}
{{DEFAULTSORT:Airborne Wind Turbine}}
Category:Electrical generators