Give Me a Brake!

One of the biggest changes in lifestyle when I moved to New York was the switch from private transportation to public transit.  While I love that I can sit on the MTA and just read as I’m going to wherever I’m headed to, I wished I was back in my old Volvo XC90 every time the subways brake.  Saying the grating noise was unpleasant for me was an understatement, but as any New Yorker, I got used to it and bore through it.

However, a new pilot project currently conducted by the Southeastern Pennsylvania Transportation Authority (SEPTA) could provide some comfort in knowing that when the brakes grind against the rails, they’re also making energy.  The pilot project, funded by the Pennsylvania Energy Development Authority and partnered with Viridity Energy, hopes to install a smart electrical grid in the Philadelphia transit system to cut electricity bills.  Currently, the project involves 38 substations within the transit system and is expected to generate $500,000 worth of electrical energy per year.  The ultimate goal is to be able to cut SEPTA’s electrical bills by 40 percent as well as generate revenue through selling electricity back to the grid.

The smart grid system harnesses regenerative braking technology in order to generate electricity as the subway cars brake.  The electricity produced is stored in large batteries within the cars and released into the electrical grid when needed.  This is different from the current system in SEPTA’s, which can redistribute regenerative energy from one train’s braking action into another’s acceleration, but only when they happen simultaneously.  In fact, many city subway transit systems have some sort of regenerative braking ability; for example, the MTA subway car-models that run on the 2 Line icon, 4 Line icon5 Line icon6 Line iconL Line icon and N Line icon routes have regenerative braking that feeds energy back to the Third Rail.

Many systems, however, don’t have a storage capacity, which is useful since not all energy can be used the minute its produced.  The SEPTA project is geared towards finding a storage solution to the issue.  However, the project is faced with two challenges.  One is finding a battery that can store and release electricity for hundreds of thousands of cycles.  The other is developing software to be able to simultaneously analyze electrical data from SEPTA’s grid and the surrounding electrical grid in order to determine energy use from the stored energy.

While cutting its own electrical bill is one goal, the project also has the broader objective of helping to contribute to the surrounding energy grids.  When demand for electricity is high, price for that electricity also rises; so, it may be more economical during these times to sell electricity back to the local energy grids.  This would help more urban areas where energy demands fluctuate greatly simply because many more buildings and electricity using facilities exist within a small area.

With the economy still struggling to pick itself up and city budgets still tight, public transit systems should watch this project closely.

Maybe if the MTA picked this up, I wouldn’t mind hearing the brakes screech.  At least I know that on a cold autumn day, part of the heat energy will probably come from those annoying brakes.



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