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. courtesy Altaeros
The Quest To Harness Wind Energy At 2,000 Feet -- Popular Science
High-altitude wind contains enough energy to power the planet. A Boston start-up wants to be the first to bring it down to Earth.
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.
Read more ....
My Comment: People are protesting windmills on the ground .... I expect the same protests for these wind turbines 2,000 feet in the air.