The design and application of utility-scale battery storage varies by region

U.S. Energy Information Administration ---------- About two-thirds of utility-scale battery storage power capacity installed in 2016 in the United States is located in two electricity markets: the California Independent System Operator (CAISO), which covers much of California, and the PJM Interconnection, which covers all or parts of 13 eastern states and the District of Columbia. Utility-scale battery systems have been installed in these markets for different reasons. Utility-scale battery storage systems in California tend to serve energy-oriented applications, with smaller power capacities but longer discharge durations. Conversely, systems in PJM tend to serve power-oriented applications, with larger power capacities but shorter discharge durations. Unlike most electricity generators, which can be characterized by their power capacity, batteries are characterized by two metrics: power capacity and energy capacity. Power capacity, measured in megawatts (MW), is the maximum instantaneous amount of power that can be produced on a continuous basis. Energy capacity, measured in megawatthours (MWh), is the total amount of energy that can be stored or discharged by the battery. To learn more click on the picture below to read the article.