Public Transit in Pennsylvania Becomes Smart Consumer and Energy Producer

An innovative public transit energy storage system is producing over US$250,000 in energy savings and earned revenues per year.
Published: Mon 23 Jun 2014

Impressive results of a six-month pilot programme of an innovative public transit energy storage system (ESS) has been released by ABB. The programme was designed with the aim of transforming the Southeastern Pennsylvania Transit Authority (SEPTA) from an inefficient energy consumer into a smart consumer and energy producer.

Partnering with smart grid technology firm Viridity Energy and Saft Battery, ABB led the design, supply and integration of the “Wayside Energy Storage Project” within Southeastern Pennsylvania Transit Authority’s ageing transit infrastructure.

Capturing wasted energy

The system is designed to capture braking energy for redistribution into the Authority’s power network. Revenue is also generated with behind-the-meter load response to sustain the local grid and wholesale energy market.

The programme involves the usage of an energy storage system (ESS) and “regenerative braking” which captures kinetic energy from the decelerating train. It is this energy which is converted into electricity. The potential of this energy storage system is discussed in our article, Stored Train Energy Helps Balance the Grid.

“Recovering energy lost during braking is one of Southeastern Pennsylvania Transit Authority’s primary energy-saving initiatives,” says Jacques Poulin, Product Manager of Energy Storage, ABB Rail Transportation. “Eventually, the industry-wide deployment of these smart grid technologies will deliver substantial economic and environmental benefit to public transit systems.”

ABB deployed the ENVILINE ESS which connects to the catenary or “third” rail of the train system to recover this otherwise wasted energy. 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 organisation which co-ordinates the movement of wholesale electricity.

All about sustainability

So far, results show that the substation system on the Market-Frankford Line in North Philadelphia produces more than US$250,000 in energy savings and earned revenues per year. This initiative is part of Southeastern Pennsylvania Transit Authority’s Sustainability Program goal of reducing energy use per passenger mile by 10% by the year 2015.

The groundbreaking initiative shows how Southeastern Pennsylvania Transit Authority and other transit authorities can participate in two key energy markets: frequency regulation (helping PJM maintain the desired grid frequency) and economic load response (reducing consumption during peak demand when prices are high.)

The transit authorities are uniquely positioned to forever change their cost structure by harnessing regenerative braking.