Last year, two MIT students won a prestigious international design award for a novel idea: Turn footsteps into electrical energy. The proposal imagined that an Italian train station would install a special floor. As passengers raced to catch their trains, the energy in their stomps would feed through an electrical system and power the building's lights. Cool idea, but it only existed on paper.
A year later, Tokyo is rolling out the real thing. The East Japan Railway Company will be testing "power-generating floors" in ticket gates and staircases. As people move through the gates, they'll step on stone tiles that give a little under the weight. That slight movement is captured and turned into energy. You can learn more about the process, called piezoelectric conversion, in a Monitor article from last year.
The railway company hopes this new round of testing will help it increase the energy yield. At the beginning of the 2008, it announced a tenfold improvement in captured power per person.
These newer floors also last longer than the originals. Early prototypes wore out and could only capture a third of their original intake after three weeks. Then, designs emerged that could still pull in two-thirds of the energy after seven weeks.
A new model began testing this month in Tokyo. By February, the company hopes to announce that the testing proved another tenfold increase in the amount of power generated and that it will still run at 90 percent two months after installation.
[Editor's note: The original version of this article misstated the amount of energy drawn from the prototype floor.]