For years, battery systems have only played a marginal role in U.S. electricity networks, with power utilities focusing more on building out capacity from natural gas plants and renewable energy sources. According to energy data portal Cleanview, five years ago, the United States had 74 times more wind farm capacity and 30 times more solar capacity than battery capacity within its power generation system. However, steady cost declines coupled with rising energy density levels have encouraged utilities to ramp up their battery installations, with…