Human parasitic generators

The Wall Street Journal today has an article on capturing energy—through the use of “parasitic generators”—released as a byproduct of human activities, such as exercising or dancing.

Here are some of the projects cited:

• The California Fitness health club in Hong Kong is using car batteries and inverters to capture 300 W from elliptical machines.

• The Dutch environmental group Enviu is building a nightclub that may include a piezoelectric dance floor that converts dancer-induced vibration into electricity. As Fast Company puts it, “The club's dance floor/generator harnesses teen angst to create electricity.”

• Lightning Packs, founded by biology professor Larry Rome, has developed a prototype backpack that generates 15 W from the jiggling motion of walking. See the schematic diagram here.

• Facility:Innovate is developing flooring materials that incorporate microturbines to generate electricity from the motion of crowds.

Such approaches can have downsides. For example, the Journal reports that if all California Fitness machines were in use 10 hours per day, it would take 82 years to recoup the initial $15,000 investment. And Enviu’s 20×20-ft. floor might cost $260,000 and generate only enough power to run some lights embedded in it.

But it’s a start, and we can hope economies of scale will lower prices.

For more on capturing “free” energy, see “Harvesters gather energy from the ether, power lightweight systems” in sister publication EDN.