The results of a six month pilot program of an innovative public transit energy storage system (ESS) designed to transform the Southeastern Pennsylvania Transit Authority (SEPTA) from an inefficient energy consumer into both a smart consumer and producer of energy are in. ABB partnered with smart grid technology firm Viridity Energy and Saft Battery, leading the design, supply and integration of the “Wayside Energy Storage Project” within SEPTA’s aging transit infrastructure.
The initiative demonstrates how SEPTA and other transit authorities can participate in two key energy markets: frequency regulation (helping PJM maintain desired grid frequency) and economic load response (reducing consumption during peak demand when prices are high).The initiative supports SEPTA’s Sustainability Program goal of reducing energy intensity (energy use per passenger mile) by 10 percent by 2015. The system captures braking energy for redistribution into the SEPTA power network while generating revenue with behind the meter load response to sustain the local grid and the wholesale energy market.
Originally started in 2012, the results to date show that the single substation system on the Market-Frankford Line in North Philadelphia generates more than $250,000 of annual energy savings and earned revenues.
“Recovering energy lost during braking is one of SEPTA’s primary energy-saving initiatives,” said Jacques Poulin, energy storage product manager, ABB Rail Transportation. “Eventually, the industry-wide deployment of these smart grid technologies will deliver substantial economic and environmental benefit to public transit systems.”
In this project, the functionality of the ESS was expanded to feed the energy back to the trains, while additionally modulating the load of the substation as a revenue generating asset connected to the PJM network, the regional transmission organization (RTO) that coordinates the movement of wholesale electricity.