The US Energy Storage Monitor explores the breadth of the US energy storage market. This quarter's release includes an overview of updates in the US energy storage market, with new deployment data from Q4 2021. It includes key trend analysis for policy landscape, system price trends, VC investments, M&A, vendor activities and deployments across residential, non-residential and front-of-the-meter segments. The report culminates in a market outlook through 2026. In Q4 2021, the US energy storage market installed 1,613 MW / 4727 MWh, another record-breaking quarter for installations. Overall in 2021, 3.5 GW/10.5 GW of new storage was added to the US grid, helping integrate renewable energy and support a healthy grid - despite supply chain challenges, project development delays, and regulatory hurdles.