The U.S. added 4.7 GW/17.2 GWh of utility-scale battery energy storage systems (BESS) in the second quarter (Q2) of 2026, taking the cumulative operational capacity past the 50 GW milestone, according to the American Clean Power Association (ACP).

Developers commissioned 50 utility-scale battery storage projects during the quarter, adding 4,685 MW/17,177 MWh of capacity. Cumulative operational battery storage capacity reached 52,945 MW/152,733 MWh at the end of Q2.

The U.S. battery storage market had crossed 25 GW of installed capacity in 2024, after surpassing 10 GW in 2023 and 5 GW in 2021. ACP expects the market to reach 100 GW of installed capacity by the end of the decade.

The first half (1H) of 2026 was the strongest first half on record for battery storage installations. Capacity additions during Q1 and Q2 were more than 14% higher than in 1H 2025, which previously held the record for first-half installations.

Battery storage accounted for 27% of all clean power capacity additions during Q2 2026.

Storage Pipeline

The U.S. battery storage development pipeline stood at 56,416 MW at the end of June 2026, comprising 23,590 MW under construction and 32,826 MW in advanced development. The pipeline increased 21% from Q2 2025.

ACP defines advanced development as projects that are not under construction but have secured a power purchase agreement, placed a firm equipment order, or are moving forward with plans to be placed under utility ownership.

On a quarter-over-quarter basis, the battery storage pipeline grew 5% to a record level in Q2.

California led the country in battery storage capacity in advanced development with 4.1 GW. Across all clean power technologies, battery storage accounted for 26% of the 116,558 MW of capacity in advanced development at the end of Q2.

Clean Power Additions

Overall, U.S. developers commissioned 17,058 MW of utility-scale solar, battery storage, and land-based wind capacity during Q2 2026, an increase of 45% from 11,758 MW in the same quarter last year. The additions were also more than 10 GW higher than the 6,860 MW installed in Q1 2026.

Developers brought 164 utility-scale solar, battery storage, and wind projects online during the quarter. The Q2 additions took installations during 1H 2026 to 23.9 GW, making it the strongest first half on record for overall clean power deployment.

Utility-scale solar accounted for the largest share of installations, with 7,405 MW, or 43% of the total. Land-based wind followed with 4,969 MW, or 29%, while battery storage contributed 4,685 MW, or 27%.

The country’s cumulative operational clean power capacity reached 387,606 MW at the end of the quarter.

Thirty three states commissioned new clean power projects during Q2, and 11 states added battery storage projects. New Mexico led overall clean power additions with 4,034 MW, followed by Texas with 3,135 MW and Arizona with 2,622 MW.

New Mexico’s lead ended Texas’ two-and-a-half-year streak as the country’s top state for quarterly clean power capacity additions, driven largely by the commissioning of the SunZia Wind project.

Clean power procurement totaled 14.5 GW during Q2, increasing 23% year-over-year. Power purchase agreement announcements also reached an all-time record for the first half of the year.

Solar and Wind

Utility-scale solar installations reached 7,405 MW during Q2, the highest recorded for a second quarter. Installations increased 102% quarter-over-quarter and 27% year-over-year. Cumulative operational utility-scale solar capacity reached 168,599 MW.

The utility-scale solar development pipeline increased by 7.7 GW, or 7%, from Q1 to a record 111 GW. Solar accounted for 54% of the country’s overall clean power development pipeline.

Land-based wind developers commissioned 4,969 MW during Q2, the strongest second quarter on record. The additions were heavily influenced by Pattern Energy’s 3,650 MW SunZia Wind project in New Mexico, which accounted for 73% of the wind capacity installed during the quarter. ACP said SunZia is the largest land-based wind project ever built in the U.S. Cumulative land-based wind capacity reached 165,888 MW.

However, the land-based wind development pipeline declined 4% during the quarter. ACP attributed the decline to a federal pause on permit reviews by the U.S. Department of Defense, which prevented early-stage projects from advancing to equipment ordering and offtake agreement stages.

The overall U.S. clean power pipeline reached 204,568 MW at the end of Q2, increasing nearly 10 GW, or 5%, from the previous quarter. The pipeline was also about 20 GW, or 11%, higher year-over-year, reaching a record level.

The overall U.S. clean power pipeline reached 204,568 MW at the end of Q2, increasing nearly 10 GW, or 5%, from the previous quarter.

U.S. installed a record 18.9 GW/51 GWh of energy storage in 2025, increasing 52% YoY.