In just six months, San Diego Gas & Electric Company (SDG&E) - a Sempra Energy utility, constructed North America’s largest lithium ion battery storage facility in Escondido, California. With it, they demonstrated a key component of the smart grid technology that will serve to maximize the potential and availability of renewable energy resources. The 30 megawatt Escondido facility contains 400,000 battery packs capable of storing 120 megawatt hours of power—enough to power 20,000 homes for four hours.