The cost of energy storage battery in the United States has dropped sharply in recent years
According to the U.S. energy information administration, the average energy capacity cost of utility scale battery storage in the United States has rapidly decreased from $2152 / kwh in 2015 to $625 / kwh in 2018. By the end of 2018, the installed power capacity of the battery in the United States was 869 MW (the maximum power that the battery can provide at a given time), and the battery energy capacity was 1236 MWh (the total energy that the battery can store).
The United States increased its battery storage capacity by 152 megawatts in 2019 and 301 megawatts between January and July 2020. According to the planned new capacity data reported by developers and power plant owners as of July 2020, battery storage is expected to increase by more than 6900 MW in the next few years.
Large scale electrochemical energy storage is increasingly paired with renewable energy power plants to improve the reliability and resilience of the grid. In 2019, California's battery installed capacity ranks first among all States in the United States, with an average battery storage cost of $1522 / kWh. About two thirds of California's battery storage capacity is used for frequency regulation and also provides energy oriented services, including ancillary services, black start services, and transmission congestion mitigation.