Crowds may soon be kicking up clean energy in England. Designed to generate power from footsteps, "heel strike" generators are ready to be installed in shopping malls and subways—and power thousands of light bulbs. "It works by using the pressure of feet on the floor to compress pads underneath," the London Times explains, "driving fluid through mini-turbines that then generate electricity, which is stored in a battery."
Based on generators in US soldiers' boots, the devices will likely get a trial run at Spinnaker Tower, a tourist hotspot in Portsmouth. Bridges, stadiums, and anywhere people congregate are not far behind. Smaller versions can have domestic uses too, experts say, like firing up your iPod. (More clean energy stories.)