One of the biggest problems with generating power from wind is the fact that breezes come and go. They vary in force and reliability, making wind a subsequently unreliable source of energy.
But engineers at Makani Power knew that wind was relatively strong and constant a quarter mile up, decided to bypass traditional, anchored wind turbines and built one that could fly.
This power plant fly:
According to Makani Power's website, this is "the first kind to demonstrate both power generation and the autonomous flight modes needed for launching, landing and crosswind flight." The craft -- Wing 7 -- weighs 130 pounds with a wingspan of Wing 7 has a wing span of 8 meters with a rated power of 20 kilowatts.
Popular Science has more on the technology:
Wing 7 takes off vertically with rotors up, rotates into horizontal flight and autonomously flies in swooping circles. Wing-mounted turbines generate electricity, transmitting it to the ground through the tether. A first-of-its-kind vertical tail wing allows the craft to transition through the various flight modes, [Corwin] Hardham says: "It's a whole new take on aviation." Eventually, fleets of autonomous, power-producing craft may be tethered to land or to buoys at sea.
With funding from the Department of Energy's Advanced Research Projects Agency-Energy (ARPA-E) — as well as from venture capitalists such as Google founders Larry Page and Sergey Brin — Makani plans to develop a 1-megawatt unit by 2013 that can fly above 1,800 feet, with hopes of taking it to market two years later.
The Wing 7 Program is an 18 month program and this flight marks the program's third milestone. Makani will later demonstrate launching and landing on a perch and a full power curve that complies with the International Electrotechnical Commission's standards.