Dec 30 2009

Sweat Power

Posted by: Jonathan Marshall

In ancient times, slaves provided the power to grind corn between millstones (Job 31:10). Today, human power is having a comeback--at college gyms, where sweaty student generate electricity on specially equipped elliptical machines.

With financial help from the local electric utility, the University of Oregon installed 20 such machines at the Student Recreation Center and connected their generators to the grid. If the students keep them busy, the machines collectively can deliver 6,000 kilowatt hours a year, enough to meet the needs of one reasonably efficient house in the region.

The machine's maker, Florida-based ReRev, claims that a 30-minute workout provides enough power to light up a compact fluorescent bulb for two and a half hours, or to run a laptop computer for an hour.

"We're not going to get off Middle Eastern oil by connecting up all the ellipticals all over the country," said U of O's sustainability director, Steve Mital. "We bought it and installed it mostly because it's an educational opportunity. People will be on those things sweating away and it gets them thinking."

The attraction of sweat power is apparently catching on. The University of Nebraska now has seven ReRev machines in the campus rec center. A special monitor shows students how much power they are generating--giving them an extra incentive to work out and stay in shape.

Cal State San Bernardino hooked up 20 of the machines this August, in time for the start of fall classes.

Conceding that the output of the machines is only a tiny fraction of the power used in the building that houses them, and that the cost of generation is uneconomic, the university's director of recreational sports said, "What we are doing is generating clean electricity and educating our students about how they can be green."

Hopefully, it will also get them to think about how much progress humanity has made since the days when all power came from people or animals. There's a lot to be said for being able to flip a switch when we want to power up our computers, rather than having to head for the gym.

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