Harvesting the Energy of Footsteps

What a cool idea!

...Like solar and wind proponents, vibration harvesters argue that abundant, clean energy is all around us and goes to waste. The challenge is how to store the power efficiently so it provides a continual output even if the vibrations from footsteps or passing trains temporarily taper off.

Price has charged Jim Gilbert, an engineering lecturer at the University of Hull, with developing the prototype system for capturing footfall. Gilbert is working with hydraulic-powered heel-strike generators, which he believes could be installed in the floors of busy public places like subway stations. Those stations typically capture the footfall of 20,000 commuters an hour during peak usage -- multiplied by 5 to 7 watts a person, that's more than enough to power a building's lights for the day.

"A few years ago I was asked to develop heel-strike generators for military applications -- generators inside boots to power cell phones so soldiers wouldn't have to carry around heavy rechargeable batteries -- but it was very difficult to ensure that the generators inside the boots didn't get dirty or wet," says Gilbert.

Inside the floor, far from the elements, Gilbert thinks the generators will be safer, but they still need to be robust and reliable to withstand the tromping of tens of thousands of people. - read more on wired