Grid Scale, Storage

Energy Storage from Subway Brakes Takes Off in Pennsylvania

A battery energy storage network based on the capture and reuse of the energy created by braking subway cars will help Southeastern Pennsylvania Transportation Authority (SEPTA) reduce operating costs, ensure energy resiliency, and support the stability of the energy grid, SEPTA said on Jan. 21.

Constellation, a subsidiary of Exelon Corp., will fund, own, and operate the 8.75 MW battery storage network, which will be deployed at seven SEPTA substations.

According to SEPTA, the network is designed to use stored energy to power trains as they accelerate from stations and can provide emergency generation for trains in the event of a power outage. Building on SEPTA’s 1.8 MW battery storage pilot program completed in 2014, the new network brings the agency’s total battery storage capacity to more than 10 MW.

The stored energy will help to balance electric load on the PJM Interconnection, SEPTA said. Philadelphia-based energy market services provider Viridity Energy will bid the batteries into the PJM market as frequency regulation resources to help match generation with demand and maintain the desired electrical frequency on the grid.

“SEPTA’s Sustainability Program is all about finding and deploying cutting-edge innovations to reduce costs in addition to improving environmental performance,” SEPTA General Manager Jeffrey Knueppel said in a statement. “This project is right in that sustainability sweet spot, and we are pleased to partner with Constellation and Viridity in bringing it to market right here in the Philadelphia region, an emerging hub for innovative energy projects.”

ABB will provide engineering, procurement, construction and operations services to Constellation for the project, and Saft will provide the lithium-ion battery technology.

SEPTA said that construction activities are scheduled to begin in 2Q16, with estimated commercial operation by the end of the year.

Lead image: Subway cars. Credit: Shutterstock.