A lighter-than-air turbine to harness high-altitude winds

Source: By Nancy Szokan, Washington Post • Posted: Thursday, October 2, 2014

Think of it as a Goodyear blimp for the era of alternative power. Well, sort of. What Erik Sofge describes in the October issue of Popular Sciencemagazine is a kind of giant tubular helium balloon with a three-bladed turbine inside, floating as much as 2,000 feet in the air so it can capture energy from winds that blow stronger and more steadily than they do at ground level.

It’s the BAT, for buoyant airborne turbine, a robotic airship being developed by Altaeros Energies, a company founded in 2010 at the Massachusetts Institute of Technology. The system is designed to deliver energy to a ground station via one of the cables that would tether the balloon to Earth.

Besides reducing one of the big problems with earthbound wind power — that the electric grid, designed for continuous transmission, doesn’t work well with fickle winds — the BAT is supposed to be mobile: It could be inflated, tethered to a ground station built on a trailer platform, then deflated and moved. “We have a vision of putting out a product that you could deploy, leave there for a year or two, pack down and move to a new site or a new customer,” says Adam Rein, lead director of Altaeros.

Altaeros has already tested a prototype 500 feet above a site in Maine. With the aid of a $740,000 grant from the Alaska Energy Authority — which is interested in power sources for the state’s many communities that are off the electrical grid — Altaeros is working on a commercial BAT that will house a 30-kilowatt turbine, which could power about a dozen homes. Later versions, Rein said, would be 200-kilowatt models, big enough to compete with generators that typically power remote mines and construction sites. “We’re not trying to replace wind turbines,” Rein says. “We’re trying to expand wind energy to places where it doesn’t work today.”