Beacon Power, a provider of energy storage systems and services, said it has energized and interconnected 8MW of flywheel energy storage and is now earning revenue at its frequency regulation plant in Stephentown, New York.

All interconnection systems between the Stephentown plant and local utility provider NYSEG’s substation are operational to enable the full 20MW plant to come online.

The company said that additional megawatts of energy storage capacity will be progressively energized.

Beacon announced last month that it was ready to connect a substantial portion of the plant to the grid and was waiting for NYSEG to finish testing the substation.