It seems like a brilliant green-power scheme: Capture the unharnessed energy created by people working out in health clubs. But there’s a problem with this plan, contends IEEE Spectrum’s Tom Gibson after crunching the numbers: The actual energy gains are small, especially in relation to the cost of retrofitting existing gym equipment.
Consider, for instance, how long you’d need to pedal a stationary bike to power a clothes drier for an hour, for instance: About 40 hours. You could power a coffee maker with 10 hours of riding, or a laptop computer with about 30 minutes of bike time. Ultimately, Gibson concludes, exercise-generated power wouldn’t offset much of a health club’s energy use, and its long payback time doesn’t make much economic sense either:
So are these electricity-producing exercise machines merely a marketing gimmick, something to make gym patrons feel good about their workouts? At the moment, that would seem to be the case. Gyms that have embraced the technology say that by advertising themselves as greener than regular gyms—and gyms are notorious power hogs—they can attract environmentally conscious consumers. And if enough customers choose that gym rather than another one down the street, the initial investment will pay for itself much faster.
Gibson goes a bit overboard in his zeal to debunk the green-gym folks—did he really need to include charts showing that exercise bikes cannot in fact power the nation?—but at least he lets supporters have their say. Three U.S. companies are working to market the technology, and to defend themselves from doubters like Gibson:
Backers of the technology respond by comparing the current cost of these machines with that of technologies like compact fluorescent bulbs or solar and wind power, which many people doubted would ever take off. They claim it’s only a matter of time until every exercise machine comes equipped with a generator. And with some 30,000 gyms in the United States, that would mean millions of machines—and many more in people’s homes—whose combined energy would then be appreciable.
Source: IEEE Spectrum