Hooray for recycling and reusing resources, especially electricity! The Southeastern Pennsylvania Transportation Authority (SEPTA), in Philadelphia, PA, is installing a battery to collect all the energy that the subway cars put out during their daily commutes.
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. The pilot project, which involves one of 38 substations in the transit system, is expected to bring in $500,000 a year. This figure would multiply if the batteries are installed at other substations.
What a great idea! It keeps power-production local, and is a creative use of resources. And it saves money. Read more at Technology Review: Subway Trains to Generate Power for the Grid.