Panels that generate energy from vibrations have been laid by ticket gates through which up to 80,000 passengers pass every day at Tokyo Station.
In theory, the piezoelectric system - consisting of slates, rubber sheets and ceramics - can generate enough energy to power automatic ticket gates or electric billboards at the station.
'This experiment is one of our ideas to help the environment,' said a spokesman for the joint venture between Japan East Railway and a government-backed group that has begun testing the system.
It is expected that the floors will produce 1,400kW/sec each day.
Tokyo Station is one of the country's most used and is the terminus for many of Japan's famed Shinkansen, or bullet trains.
Japan has tried to project itself as a leader in the fight against global warming, but like many other countries it is far behind in meeting its obligations under the Kyoto Protocol.
