Fat into fuel

Julie Brown

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Sometimes, watching people running, cycling, and rowing away their excess calories at the gym, it’s hard not to think, “If only we could harness that energy . . .” Henrique Rocha ’09 did something about it. Estimating that the total electrical generating capacity of the fitness center in the Payne Whitney gym is about 10 kilowatts per day—enough to power a couple of average-sized homes—Rocha worked with his adviser, associate professor of electrical engineering Hur Koser, to build a mechanism that uses the energy a person expends on an exercise machine to charge an iPod or cell phone.

Their invention, installed on some 40 machines in the Adrian C. “Ace” Israel Fitness Center, is the centerpiece of the Green Gym Project, a collaboration between Koser’s lab, the athletics department, and Yale’s Office of Sustainability. One day they hope to ratchet up the project to power the entire fitness center—televisions, lights, bathroom hand dryers—via the sweat and toil of the buff.