These days everyone is talking about alternative sources of energy. In the United States, President Barack Obama is touting the virtues of alternative energy technology, and the promise of green jobs, as well as reducing dependence on foreign oil and other environmentally harmful energy sources. The rest of the world is following suit, but the Japanese have really taken the lead in at least one area — kinetic energy generated by crowds of people walking through turnstiles at train stations. The new energy source uses piezoelectric foot mats installed beneath the ticket turnstiles to generate kinetic energy.
The 90 square centimeter mats can generate enough energy to power the station’s LED display boards, as well as lights along the stations inner walls. The alternative power source is still a prototype program, and has so far only been installed in one Tokyo location, the huge Shibuya Central Station, which generates traffic in excess of 2.4 million commuters on a daily basis.
All those commuters walking through the same corridors generates what is sometimes called “mechanical stress,” and the kinetic energy released from walking over the mats can be stored temporarily in large capacitors before being sent to wall displays and lights. The SoundPower Corp. designed and installed the kinetic energy mats, and the company claims that even though the prototype units only generate a minimal amount of electrical current, if used on a large-scale (say, covering the entire floor of a major train station, for example), the energy produced could be significant indeed. Perhaps even enough to power the entire station in real-time.
Alternative energy experts believe the Japanese could be onto something here — using kinetic energy in areas of constant motion and movement such as train stations or airports could theoretically generate enormous amounts of stored power. But the catch, as always, lies in the cost. So far, the piezoelectric mats are proving costly to design and install. If this process can be automated, and costs significantly reduced, it could be possible to cover vast amounts of indoor terrain with the power generating mats.
A piezoelectric mat installation is also being set up in a second Japanese train station, this time storing up the energy, rather than using it to power LEDs or incidental lights. Until the technology improves so that the foot powered kinetic energy can produce a significant amount of voltage, storing up the energy as a backup resource may be the most practical use of the technology.
