Finally, SEPTA isn’t shitting the bed…
Vehicles without regenerative braking are throwing away a lot of energy every time they brake (movement is converted into heat via friction on the brake pads). Hybrid and electric car address that problem by capturing as much of that energy as possible and converting it into electricity, and the same might be about to happen to subway trains with the added twist that it would be tied to the (smart) power grid. The Southeastern Pennsylvania Transportation Authority (SEPTA) is experimenting with regen braking, a move that it estimates could slash its electricity bills by “up to 40 percent and generate millions of dollars a year.
via Treehugger