Axion Power International Inc. 's PowerCube battery energy storage and battery system is being integrated as a power resource for the PJM regulation market, which serves 58 million people in all or parts of 13 states and the District of Columbia. The use of PowerCube on the PJM market marks the first time an external energy storage system has been integrated into a major power grid.

Axion Power, working in partnership with Philadelphia-based Viridity Energy on this and other projects, will initially participate in the PJM market as a 100 kW resource that will soon be ramped to higher kw levels. As a curtailment service provider in PJM, Viridity Energy will be managing the Axion PowerCube, a highly mobile and scalable 500kW/250kW battery energy storage System.

A recent ruling by the Federal Energy Regulatory Commission (FERC) reduced the minimum participation requirement from 500 kW to 100 kW and increased the compensation paid to regulation resources, paving the way for the use of the PowerCube on the PJM project.