The Energy Information Administration (EIA) made an early release of the 2021 EIA-860 data reporting that battery energy storage capacity grew more than 300% year over year, increasing from 1.4 GW in 2020 to 4.6 GW in 2021.
The boost was largely driven by the 106 utility-scale battery projects that reached commercial operations, with 3.2 GW of capacity. Consistent with historic trends, about 78% of all storage capacity added last year was built in regional transmission organization (RTO) service territories.
The nature of battery energy storage deployment advanced last year, as operators are reporting more applications and use cases for the technology beyond the conventional ancillary services that have characterized the technology since it began to ramp up deployment in 2016. Ancillary services such as frequency response and ramping/spinning reserve were the dominant use cases of battery energy storage over the last several years and continue to be a significant part of the work that utility-scale batteries perform.“