We get lots of questions from students about climate change and especially about what can be done to stop climate change.  So we’re starting a new regular column in our blog called “Ask ACE” where we share a great question that came in from a student and our answer.

If you’ve got questions related to all things green and climate science-y, just ask us!  Email [email protected] and it might get posted in a future Ask ACE column.

This question came from Allie from Brooklyn, NY who asked why people don’t try to capture the power from subway trains for electricity.

My first thought was, “Wow – such a cool idea!  I wonder if that’s possible?”

It turns out that other people think it’s a great idea, too — and they’re working to make it a reality!  The Philadelphia subway system, SEPTA, is working on testing out just such a project at one of their subway stations.  Here’s how it works:  When the trains brake on their way into the station, the brakes spin wheels that drive a generator.  The electricity it makes gets stored in a massive battery in the station.

This electricity can then get used in several ways: it can power other trains when they accelerate out of the station, or it can get fed into a smart grid that channels the electricity elsewhere.  In this case, SEPTA can sell that electricity and make themselves some money in the process.

Pretty cool!  The project won’t be up and running until next summer, but the electricity it generates is estimated to bring in about $500,000 a year, just for this one battery.  If the pilot project goes well and batteries are installed at other stations, it could save SEPTA up to 40% of its electricity bills and make even more money by selling off that extra energy.

Any volunteers to take a trip to Philly next summer and check it out?

You can read the full article on MIT’s Technology Review here.  Thank you, Allie, for such a creative idea!  I think you have a future in engineering!