Sweat Energy

California State University, San Bernardino, has installed 20 exercise machines at its Student Recreation and Fitness Center that generate energy as users walk or run.

Fitness center officials say in a university news release that a typical 30-minute workout can light a fluorescent light bulb for about 2½ hours, or a laptop or desktop computer for 30 minutes.

“Each machine generates about 100 watts of power per hour,” says Fitness Center director Rick Craig. “It's not much when you compare to the power usage, but the generated electricity goes straight back to our building to be used.”

The only sign that the exercise machines are generating energy comes from a black power strip along the front of the 20 machines. The strip is connected to a small transformer installed into a nearby breaker panel. The transformer gives readings of the generated electricity.

Craig says the cost of the equipment is about $14,000 and was paid for through student users' fees.