Battery Storage in the United States: An Update on Market Trends
The regional patterns play a pivotal role in influencing the nation-wide battery storage market structure.
Electric power markets in the United States are undergoing significant structural change that we believe, based on planning data we collect, will result in the installation of the ability of large-scale battery storage to contribute 10,000 MW to the grid between 2021 and 2023—10 times the capacity in 2019.
Energy storage plays a pivotal role in enabling power grids to function with more flexibility and resilience. In this report, we provide data on trends in battery storage capacity installations in the United States through 2019, including information on installation size, type, location, applications, costs, and market and policy drivers. The report then briefly describes other types of energy storage.
This report focuses on data from EIA survey respondents and does not attempt to provide rigorous economic or scenario analysis of the reasons for, or impacts of, the growth in large-scale battery storage.
Growth across U.S. electric power market regions
The number and total capacity of large-scale battery storage systems continue to grow in the United States, and regional patterns strongly influence the nation-wide market structure:
At the end of 2019, 163 large-scale battery storage systems were operating in the United States, a 28% increase from 2018. The maximum energy that could be stored at these sites (energy capacity) was 1688 MWh, and the maximum power that could be provided to the grid from these sites at any given moment (power capacity) was 1022 MW.
As of the end of 2019, more than 60% of the large-scale battery system capacity to store energy or provide power to the grid in the United States was located in areas covered by regional grid operators PJM Interconnection (PJM) and California Independent System Operator (CAISO). Historically, these areas attracted capacity additions because of favorable market rules promoting energy storage.
Starting in 2017, regions outside of PJM and CAISO have also seen installations of large-scale battery energy storage systems, in part as a result of declining costs.
Small-scale battery storage
Small-scale battery storage also continues to grow, especially in California, but also in other regions of the United States:
In 2019, 402 MW of small-scale total battery storage power capacity existed in the United States.
California accounts for 83% of all small-scale battery storage power capacity.
The states with the most small-scale power capacity outside of California include Hawaii, Vermont, and Texas.