Historic Project Brings Wayside Storage to Scale

January 21, 2016

In 2016 SEPTA will install seven (7) new energy storage devices on the Market-Frankford Line and Broad Street Lines. The historic project supports SEPTA's Sustainability Program pledge of "budget neutrality" and represents the first-ever fully commercial deployment of energy storage in a transit operation.

The Wayside Energy Storage System (WESS) build out was accomplished because of SEPTA's commitment to pursue new sources of revenue and cost savings, a strong partnership with Viridity Energy - a Conshohocken (PA) based smart gird firm - and a sustainability pledge to improving energy efficiency and reducing greenhouse gases.

This historic project has been several years in the making. It began in 2010 when SEPTA partnered with Viridity Energy on a WESS pilot at the "Letterly Substation" on the Market-Frankford Line (MFL) in the Kensington Section of North Philadelphia. The idea behind the pilot was to install an energy storage device (think a really big battery) at a SEPTA substation to capture, store, and reuse electricity generated from braking trains. If successful, the battery would improve energy efficiency and reduce energy demand along one section of the Market-Frankford corridor.

And successful it was. So successful in fact that shortly after the installation of the pilot WESS in 2012, SEPTA installed a second WESS at Griscom Substation, also on the MFL in the Frankford Section of Northeast Philadelphia. The purchase of this battery was made possible through a $1.44M grant from the Federal Transit Administration (FTA).

Now SEPTA,Viridity Energy, and Constellation have determined that the optimal economic approach to the buildout features 8.75 MW of energy storage capacity deployed at seven (7) substations.
The battery storage project requires no upfront capital investment from SEPTA. It will be financed through a 20-year battery services agreement with Constellation, who owns and operates the network.

Viridity Energy will provide energy market services for the project, bidding the batteries into the PJM market as frequency regulation resources -- matching generation with demand and maintaining the desired electrical frequency on the grid.

Buildout locations include:
o Allison Substation (Market-Frankford Line, West Philadelphia)
o Sansom Substation (Market-Frankford Line, Center City)
o Park Substation (Broad Street Line, North Philadelphia)
o Louden Substation (Broad Street Line, North Philadelphia)
o Butler Substation (Broad Street Line, North Philadelphia)
o Pine Substation (Broad Street Line, Center City)
o McKean Substation (Broad Street Line, South Philadelphia)

For SEPTA, the benefits of the project include:
o A five-fold increase in energy storage capacity at no cost or balance sheet impact
o Energy savings and potential for revenue-sharing under certain market conditions
o Resilient source of back-up power in the event of a localized or regional grid power outage, allowing SEPTA to move trains safely to the next station to unload passengers

Once each WESS is installed, SEPTA will have access to 10.55 MW of energy storage capacity in its subway system. That is enough energy to power 1 home for a year or 10,000 homes for a month!


For more information about SEPTA's first wayside energy storage device check out our "First-in-the-World" journal entry. To get a better understanding of how the wayside storage device works, check out our animated GIF.