FLYING A NEW WIND IDEA

Wind turbines take to the skies
Lakshmi Sandhana, 3 June 2010 (BBC News)

"For JoeBen Bevirt, the future of energy production is up in the clouds…The inventor is currently putting the final touches to a series of large kites, which he says will be able to harvest the fast crosswinds found at high altitude…His airborne wind turbines will take off and fly to around 2000 feet (600m), where they will float, generating power that can be transferred to the ground via a tether…

"The notion of tapping into high altitude winds was first posed in the 1970s, but was not technically possible…[R]ecent advances in materials, computing resources and unmanned aerial vehicles have now made the idea viable…[A] handful of companies are now exploring different designs…Magenn Power's Air Rotor System called (MARS) uses a helium filled blimp design, Sky WindPower is building flying electric generators and Kitegen is focused on creating power kites…"

From Joby Energy (click to enlarge)

"Joby Energy's [30kW system] resembles a large multi-winged kite…The autonomous structures are computer-controlled and can take off vertically before navigating to the desired altitude…Flight is controlled by an advanced computer system and the harnessed electricity is sent down the tether to a substation where it is converted from DC to AC power which can then be routed to a power grid.

"The technology's inventors say the devices are portable and relatively inexpensive to build when compared to conventional wind turbines and can generate twice the amount of power…[G]oing even higher should, in theory, produce even more power…The technology can potentially navigate to altitudes of 35,000 feet (10,600m), but the company has had to restrict their flying altitudes to 2000 feet or less due to concerns expressed by the US Federal Aviation Administration…If successful…a 100kW prototype [could follow] within the next year."

From BBC News (click to enlarge)

"The firm's goal is to create an initial line of systems with a power capacity of 300kW which would be capable of generating enough energy to power around 150 homes. Larger systems of 3MW or more could potentially power 1500 homes…Eventually wind farms containing several airborne wind energy turbines could be constructed to deliver power consistently…

"…[T]here are several issues to be addressed…[First, the cost is bigger than the benefit]…In addition, the firm must demonstrate reliable control systems and show that the entire system is safe…[T]he systems are engineered to be strong enough to operate in very strong winds and if the turbines ever encounter gale-force type winds, the system would land itself…The firm initially plans to deploy the technology in thinly populated areas with strong winds to road-test the technology thoroughly…"