Large-scale battery storage systems are increasingly being used across the power grid in the United States. In 2010, 7 battery storage systems accounted for only 59 megawatts (MW) of power capacity, the maximum amount of power output a battery can provide in any instant, in the United States. By 2015, 49 systems accounted for 351 MW of power capacity. This growth continued at an increased rate for the next three years, and the total number of operational battery storage systems has more than doubled to 125 for a total of 869 MW of installed power capacity as of the end of 2018. This report explores trends in battery storage capacity additions in the United States and describes the state of the market as of 2018, including information on applications, cost, ongoing trends, and market and policy drivers. These observations consider both power capacity and energy capacity, the total amount […]