Renewable Train Energy
“Subway trains will generate power for the grid with a battery that captures power from the braking trains.” Technology Review reports on energy innovation out of Philadelphia.
“The Southeastern Pennsylvania Transportation Authority, which runs the transit system in Philadelphia, is piloting a smart electrical grid technology that could cut its electricity bills by up to 40 percent and generate millions of dollars a year. A massive battery installed at one of the authority’s substations will store electricity generated by the braking systems on trains (as the trains slow down the wheels drive generators). The battery will help trains accelerate, cutting power consumption, and will also provide extra power that can be sold back to the regional power grid.”