Windbelt, Cheap Generator Alternative, Set to Power Third World
Working in Haiti, Shawn Frayne, a 28-year-old inventor based in Mountain View, Calif., saw the need for small-scale wind power to juice LED lamps and radios in the homes of the poor. Conventional wind turbines don't scale down well—there's too much friction in the gearbox and other components. "With rotary power, there's nothing out there that generates under 50 watts," Frayne says. So he took a new tack, studying the way vibrations caused by the wind led to the collapse in 1940 of Washington's Tacoma Narrows Bridge (aka Galloping Gertie).
Frayne's device, which he calls a Windbelt, is a taut membrane fitted with a pair of magnets that oscillate between metal coils. Prototypes have generated 40 milliwatts in 10-mph slivers of wind, making his device 10 to 30 times as efficient as the best microturbines. Frayne envisions the Windbelt costing a few dollars and replacing kerosene lamps in Haitian homes. "Kerosene is smoky and it's a fire hazard," says Peter Haas, founder of the Appropriate Infrastructure Development Group, which helps people in developing countries to get environmentally sound access to clean water, sanitation and energy. "If Shawn's innovation breaks, locals can fix it. If a solar panel breaks, the family is out a panel."
Frayne hopes to help fund third-world distribution of his Windbelt with revenue from first-world applications—such as replacing the batteries used to power temperature and humidity sensors in buildings. "There's not a huge amount of innovation being done for people making $2 to $4 per day," Haas says. "Shawn's work is definitely needed."
In a conventional wind generator, gears help transfer the motion of the spinning blades to a turbine where an electric current is induced. The Windbelt is simpler and more efficient in light breezes—a magnet mounted on a vibrating membrane simply oscillates between wire coils.