Financial terms of the acquisition have not been revealed.

Established in 2009, Green Charge Networks has offices in Santa Clara, New York and San Diego. It has developed a portfolio of 48 MWh of battery storage projects either deployed or under construction in over 150 sites.

The company provides risk-free shared savings energy storage and software that time-shifts power use, and optimizes electric vehicle charging, solar and energy efficiency measures.

The company has so far helped customers reduce their electric bills up to 30% and offer stability to the grid.

ENGIE North American business unit president and CEO Frank Demaille said: "With Green Charge, ENGIE immediately gains a strong position in the growing battery storage market in the U.S. and further develops its offering of load management solutions at customer sites.

"The company’s stand-alone battery and solar + battery solutions complement our existing offer. In the U.S., ENGIE has developed a large customer base across all 50 states.

"Together with Green Charge, we’re able to offer an even greater range of leading-edge solutions for commercial, industrial, and public sector customers."

Last October, Green Charge Networks announced its entry into the California Independent System Operator market.

Under its shared-savings Power Efficiency Agreement, the company contracted 61 systems and 13.3 megawatt-hours with customers throughout California to take part in utility or ISO programs.

Green Charge Networks CEO Vic Shao said: "By working with ENGIE, Green Charge looks forward both to continued growth in California as well as expansion across the U.S. and internationally.

"ENGIE’s long-term financial and commercial support presents an opportunity to scale our business to a completely new level."