The Power of Footsteps

Turning an excited concert crowd into electric current

Doesn't it seem like we're looking for energy everywhere these days? While scientists are still working hard at harvesting power from the sun, wind and waves, they're also turning to unexpected sources such as human locomotion.

Two MIT architecture students recently unveiled what they're calling the "Crowd Farm," a setup that would derive energy from pounding feet in crowded subway stations or rock concerts.

In each case, there would be a sub-flooring system consisting of independent blocks. When people walk across this surface, the forces they impart will cause the blocks to slip slightly, and a dynamo would convert the energy in those movements into electric current.

To prove the idea would work, the students built a stool that's connected to a series of four LEDs. When someone sits on the stool, the action transfers energy to the LEDs, which light up. The students say that moving from this proof-of-concept device to a large-scale Crowd Farm would be expensive, but it certainly sounds fun. One possibility: Concert-goers could boost the volume at a show. The setup would capture the energy of their pounding feet and transfer it to the speaker system, cranking up the sound.—Gregory Mone