According to the latest report from the U.S. Department of Energy’s Energy Information Administration (EIA), utility-scale battery storage systems are increasingly being installed in the United States.
Battery storage systems store electricity produced by generators or pulled directly from the electric grid and then redistribute the power when needed later. EIA noted that these systems have a wide variety of applications, including integrating renewables into the grid, peak shaving, frequency regulation and providing backup power.
According to the report, the United States had seven operational battery storage systems in 2010, accounting for 59 megawatts (MW) of installed power capacity and 21 megawatt hours (MWh) of energy capacity. By the end of 2018 (the latest data available), the United States had 125 operational battery storage systems, providing a total of 869 MW of installed power capacity and 1,236 MWh of energy capacity.
Most of the utility-scale battery storage capacity is installed in regions covered by independent system operators or regional transmission organizations. In the past, the majority of the systems were located in the PJM Interconnection (which manages the power grid for 13 Eastern and Midwestern states) and the California Independent System Operator (CAISO). In fact, between 2010 and 2018, these two systems accounted for 55% of total battery storage capacity built.
In 2018, however, according to the EIA report, more than 58% of new storage power capacity additions, representing 69% of energy capacity additions, were installed in states outside of PJM and CAISO, including Alaska, Hawaii, the Electric Reliability Council of Texas and the Midcontinent Independent System Operator.
“Many of the additions were the result of procurement requirements, financial incentives, and long-term planning mechanisms that promote the use of energy storage in the respective states,” said the report.
Cost reductions have also been an incentive for more and more areas to install the technology. In 2015, for example, the average cost per unit of energy capacity was $2,153 per kilowatt hour (KWh). By 2017, that had dropped to $834 per KWh.