Altaeros' Buoyant Air Turbine
Last year, Altaeros tested a prototype of the turbine at a height of 500 feet in Maine, where it flew in 45mph winds.
Nothing about the grooved, inflatable body taking shape inside Greentown Labs in Somerville, Massachusetts, resembles a wind turbine. It looks more like a jetliner's emergency ramp, or something you'd tie behind a boat and cling to desperately while bumping across the surface of a lake. But the 14-foot-long structure most resembles what it actually is--an air-filled wing.
To be more precise, it's a stabilizing fin, part of a tube-shaped, robotic airship designed to tap the power of high-altitude winds. The blade tips of today's tallest conventional wind turbine, installed at a test center in Denmark this year, stretch to 720 feet. The fully autonomous, lighter-than-air BAT (short for buoyant airborne turbine) will climb as high as 2,000 feet, where winds blow stronger and steadier.
"There is more than enough energy in high-altitude winds to power all of civilization," says Ken Caldeira, a Stanford University climate scientist, who co-authored a 2012 study that ballparked the potential at 1,800 terawatts--more than four times the estimate near the surface. "The question is whether technologies can be created that can reliably and affordably extract it." Altaeros Energies, the company behind that BAT, is poised to prove that it's already done so.