Chris Gaylord in the Christian Science Monitor:
For two architecture students at the Massachusetts Institute of Technology in Cambridge, Mass., the sound of footsteps is an echo of energy gone to waste. They figure that the stomp of every footfall gives off enough power to light two 60-watt bulbs for one second.
“Now imagine how many people walk through a train station each morning, or walk down the street in Hong Kong,” says James Graham, who, with fellow MIT graduate student Thaddeus Jusczyk, is helping to develop the growing field of “crowd farming.”
They devised a special floor of sliding blocks that can turn motion energy (such as from a footstep) into electrical energy. As commuters march across the floor, it would collect tiny flickers of power from each stride and channel that energy.