PA: ABB Incorporates Maxwell Technologies Ultracapacitors for Braking Energy Recuperation in Philadelphia Area Electric Rail Lines

April 9, 2014
High-efficiency system reduces energy consumption and enables sale of excess power for utility grid frequency regulation.

Maxwell Technologies Inc. announced April 9 that it is supplying ultracapacitors to ABB for its recent contract win to upgrade Philadelphia area rail lines.

As previously announced, ABB will install a hybrid version of its high-efficiency Enviline energy recovery and storage system for the Southeast Pennsylvania Transit Authority’s (SEPTA) light rail system serving the greater Philadelphia area.

ABB installed a battery-based Enviline braking energy recuperation system in a substation of SEPTA in 2012 and has now incorporated Maxwell ultracapacitors in a new hybrid configuration to increase energy recovery efficiency and extend battery life. In addition to reducing SEPTA rail vehicles’ consumption of grid-supplied electrical energy by 10 to 20 percent, the system enables SEPTA to provide frequency regulation services on the PJM Interconnection Network, a regional transmission organization (RTO) that coordinates the movement of wholesale electricity in all or parts of Delaware, Illinois, Indiana, Kentucky, Maryland, Michigan, New Jersey, North Carolina, Ohio, Pennsylvania, Tennessee, Virginia, West Virginia and the District of Columbia.

“By incorporating ultracapacitors, we will recover more braking energy, produce higher revenues from frequency regulation and extend battery life,” said Jacques Poulin, ABB’s product manager for energy storage and rail. “The SEPTA model is the first of its kind in the world, going beyond the recovery of braking energy by also helping the electricity grid to be more stable and efficient with fast regulation support.”

Braking energy recuperation systems in electric and hybrid vehicles save fuel and electrical energy by using resistance from the electric motor to stop the vehicle, thereby converting kinetic energy that would be wasted in a conventional friction-based braking system into stored electrical energy. Ultracapacitors’ rapid charge/discharge characteristics uniquely enable them to capture and store more energy during each braking event than battery-based systems, which have limited ability to absorb energy in the few seconds required to stop a vehicle. 

“Transportation is the world’s largest energy consumer, so deployment of systems that conserve energy and reduce fuel consumption and emissions are creating tremendous long-term growth opportunities for our leading ultracapacitor technologies,” said John Warwick, Maxwell’s interim president and CEO.