Intuitively, there just shouldn’t be any way for something wind-powered to move directly downwind faster than the wind itself. It’s impossible: Release a balloon, and the wind blows the balloon as fast as the wind is moving, and that’s as fast as any wind-powered object can go, before the wind. Sure, sailboats can win a race against the balloon by moving diagonally across the wind, but moving in a straight line down a 10 kph wind, and the balloon moves at 10 kph. End of story.
Or, start of story.
Rick Cavallaro and John Borton have built a cart that moves 2.86 times the speed of the wind, moving straight downwind. That may seem impossible, but after a year of tinkering and some financial assistance from Google and Joby Energy, they did it. Don’t believe me? Check out the video. Keep a weather eye out for the green flag at 0:35. Notice how it’s blowing the exact opposite direction of the orange wind socks on the cart? That’s because the cart is going faster than the wind.
How is it possible?
S.A.R.A.H. (Self-actuated Residential Automated Habitat), the talking, thinking, usually helpful house on Eureka is such a regular on the show that she could qualify as just another wacky genius in a town full of them. But though she’s smarter than any smart house ever known, she has a bit of a problem: her power source. We’re told that her radioisotope thermoelectric generator supplies plenty of power for energy independence, but these devices only output power at low levels, albeit for a long time, plus they depend on radioactive materials—which is why in real life they’re used on long-lived unmanned probes and satellites.
S.A.R.A.H.’s designer, Douglas Fargo, should take some cues from the Solar Decathlon, a biennial contest hosted by the U.S. Department of energy. This year, representatives from 20 teams have reconstructed their high-tech solar-powered houses on the National Mall in Washington D.C. for inspection by the public and judges alike. (See 80beats’ gallery of some of the houses.) Houses are scored on 10 criteria, from efficient appliances to market-worthiness.
Most of the houses share a few themes: They maximize the insulation to minimize heat and cool loss; they have large sections of walls that can be opened onto decks and patios to increase the amount of livable space in the house; they had ways to access appliances or climate controls remotely, whether from an iPhone app or an Internet connection; and all of them can, at the minimum, operate without electricity from the grid, though many generate excess power.