A Washington, D.C.-based company called Magenn Power Inc. has taken up residence in Moffett's Hangar Two, where it plans to test its floating wind turbine at heights of up to 1,000 feet, sending about 30 kilowatts of electricity down a tether. The turbine is called MARS, which stands for Magenn Air Rotor System.
Magenn CEO Pierre Rivard said fast-moving higher altitude winds are the largest source of untapped energy on Earth. At just 1,000 feet, wind speeds are often double what they are on the ground, which allows eight times as much energy to be produced. There is even talk of someday using the jet stream five miles up, where wind speeds are three times what they are at ground level.
"There is enough energy in high-altitude winds to power civilization 100 times over, and sooner or later, we're going to learn to tap into the power of winds and use it to run civilization," says Ken Caldeira, professor of global ecology at the Carnegie Institution for Science.
Going five miles up is not within Magenn's business plan, however, Rivard said, adding that the company is quite happy with what is achievable at 1,000 feet.
Rivard believes his wind turbines would be especially useful in poor or remote regions of the world where there is no electrical grid. The turbines could also be quickly deployed after natural disasters that cause major damage to electrical infrastructure. They can either compliment or replace traditional diesel generators. In many cases, the cost of buying and operating the wind turbine is expected to be "well below" that of a diesel generator, he said.
The presence of a 1,000-foot-long tether in the sky might make some people nervous about possible aircraft accidents, especially on an airfield, but Rivard said Federal Aviation Administration rules treat the wind turbine tether as if it were any 1,000-foot-tall structure. It must be registered as a flight obstacle with the FAA and must have lights at night so that pilots can see it.
MARS can sway quite a bit in the wind, so a certain "cone" of clearance has to be maintained with other objects, Rivard said. In extreme winds, MARS can be quickly winched in.
Eventually, a larger version of MARS should be able to produce 100 kilowatts of power — enough to power 15 homes, the company says.
The turbine's balloon is filled with helium to keep it aloft, but the spinning of the balloon creates its own lift through what is known as the "Magnus effect." The spinning motion also makes it more stable in the air.
It turns out that Hangar Two at Moffett is an ideal location for testing MARS, because helium tanks and wind sensors can be shared with Airship Ventures. That company operates a Zeppelin airship, taking up to a dozen people at a time on tours around the region.