Good thing I took at least one physics class at university, because it's helping me wrap my head around this one a bit. Here goes: The state of Pennsylvania (through the 2010 Pennsylvania Energy and Optimization Project) has just given a $900,000 grant to Viridity Energy that will research the potential of recycling potential energy, if you will, from the act of braking a locomotive or street trolley.

The theory behind this research is regenerative energy. This is the process of storing energy that is potentially lost (or even created), when something in motion is asked to slow down or stop. Regenerative braking isn't really new, this project is seeking to get more sophisticated about how that energy is recycled or harnessed.

For this project, Viridity Energy will work with the Southeastern Pennsylvania Transportation Authority (SEPTA) to install software that will work in conjunction with what the press release describes as one of the country's oldest transportation systems. (First electric trolleys went into action in 1892!) A large battery will capture the energy from the trains on the Market-Frankford Line, which has the highest ridership in the entire SEPTA system.

Viridity Energy's technology will be used to optimize the energy and feed it back into a high-use propulsion substation in Philadelphia. So, not only could energy be saved, but SEPTA might actually be able to create a new source of revenue for itself. SEPTA claims it could generate $500,000 in "economic value" from the pilot, and it will help SEPTA reduce its carbon emissions by 1,258 tons.

If things work out, the agency will look at deploying the technology at all 38 of its substations. The net effect is that it could significantly reduce its electricity spending.

Here's a note from Joseph Casey, general manager of SEPTA:

"Upon implementation, the storage system will serve as a foundation for measurable gains in both energy efficiency and voltage stability in this critical corridor, by providing a replicable and scalable model for broader system-wide implementation. By moving towards energy storage, SEPTA will be assuming a leadership role among transit agencies."

At the very least, SEPTA gets points on this one for innovation and for potentially providing a bridge from a transit system of the past into a smart transportation system of the future.