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, 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.
Airborne wind energy (AWE) is the direct use or generation of wind energy by the use of aerodynamic or aerostatic lift devices. AWE technology is able to harvest high altitude winds, in contrast to wind turbines, which use a rotor mounted on a tower.
Unconventional wind turbines are those that differ significantly from the most common types in use.
Wind power has been used as long as humans have put sails into the wind. King Hammurabi's Codex already mentioned windmills for generating mechanical energy. Wind-powered machines used to grind grain and pump water, the windmill and wind pump, were developed in what is now Iran, Afghanistan, and Pakistan 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, and in arid regions such as the American mid-west or the Australian outback, wind pumps provided water for livestock and steam engines.
Southwest Windpower (SWWP) was a wind turbine manufacturer established in 1987 based in Flagstaff, Arizona, United States. The company specialized in small, reliable battery charging wind generators that complement photovoltaics (solar energy or PV) in supplying energy to rural areas.
A laddermill kite system is an airborne wind turbine consisting of a long string or loop of power kites. The loop or string of kites would be launched in the air by the lifting force of the kites, until it is fully unrolled, and the top reaches a height determined by designers and operators; some designers have considered heights of about 30,000 feet, but the concept is not height-dependent. The laddermill method may use one endless loop, two endless loops, or more such loops.
SkySails Group GmbH is a Hamburg-based company that sells kite rigs to propel cargo ships, large yachts and fishing vessels by wind energy as well as airborne wind energy systems for electricity production from high-altitude winds.
KiteGen is a concept for a wind harnessing machine for high altitude winds, developed in Italy. The vertical axis rotation is intended to eliminate the static and dynamic problems that limit the size of conventional wind turbines. The prototype STEM yo-yo is under construction at Berzano di San Pietro in Italy.
GE Wind Energy is a branch of GE Renewable Energy, a subsidiary of General Electric. The company manufactures and sells wind turbines to the international market. In 2018, GE was the fourth largest wind turbine manufacturer in the world.
A tidal stream generator, often referred to as a tidal energy converter (TEC), is a machine that extracts energy from moving masses of water, in particular tides, although the term is often used in reference to machines designed to extract energy from run of river or tidal estuarine sites. Certain types of these machines function very much like underwater wind turbines, and are thus often referred to as tidal turbines. They were first conceived in the 1970s during the oil crisis.
Squid Labs was an American independent research and development company founded by a group of four MIT graduates. In 2004, Colin Bulthaup, Dan Goldwater, Saul Griffith, and Eric Wilhelm moved from the East Coast to California to found the company known as Squid Labs. During its years of existence from 2004 to 2007, Squid Labs added three more members to its team: Geo Homsy, Corwin Hardham and Ryan McKinley. Working out of a warehouse in Emeryville, the group adopted the slogan "We're not a think tank, we're a do tank." and created a handful of patents and inventions including an electronically sensed rope, portable pull-cord generators, and a machine that could manufacture eyeglasses of any prescriptions at extremely low cost. Squid Labs was also the birthplace for many companies still running today, such as Makani Power and Howtoons. Although the company no longer exists, Squid Lab's co-founder, Saul Griffith created a similar company in San Francisco named Otherlab.
James G.P. Dehlsen is an American businessman, inventor, and entrepreneur. He is a pioneering figure in wind power and renewable energy development in the United States and holds 25 patents.
Makani Technologies LLC was an Alameda, California-based company that developed airborne wind turbines. Founded in 2006, Makani was acquired by Google in May 2013. In February 2020, Makani was shut down by Alphabet, Google's parent company.
X Development LLC, doing business as X, is an American semi-secret research and development facility and organization founded by Google in January 2010. X has its headquarters about a mile and a half from Alphabet's corporate headquarters, the Googleplex, in Mountain View, California.
Crosswind kite power is power derived from airborne wind-energy conversion systems or crosswind kite power systems (CWKPS). The kite system is characterized by energy-harvesting parts flying transverse to the direction of the ambient wind, i.e., to crosswind mode; sometimes the entire wing set and tether set is flown in crosswind mode. From toy to power-grid-feeding sizes, these systems may be used as high-altitude wind power (HAWP) devices or low-altitude wind power (LAWP) devices without having to use towers. Flexible wings or rigid wings may be used in the kite system. A tethered wing, flying in crosswind at many times wind speed, harvests wind power from an area that exceeds the wing's total area by many times.
Donald Lewis Montague is a Canadian-American watersport athlete and designer. He is President of Kai Concepts, co-founder of Makani Power, and the head of the Kiteboat Project in Alameda, California.
Ampyx Power is a Dutch company based in The Hague whose aim is to develop utility-scale airborne wind energy systems. The company was founded in 2008 by Bas Lansdorp and Dr. Richard Ruiterkamp and is currently focused on verification testing of a 150 kW technology demonstrator, which will be the basis for a commercial product at utility scale.
Kitepower is a registered trademark of the Dutch company Enevate B.V. developing mobile airborne wind power systems. Kitepower was founded in 2016 by Johannes Peschel and Roland Schmehl as a university spin-off from the Delft University of Technology’s airborne wind energy research group established by the former astronaut Wubbo Ockels. The company is located in Delft, Netherlands, and currently comprises 18 employees (2018).
