A review of newly released U.S. Energy Information Administration (EIA) data indicates that utility-scale solar generation increased 29% over the past year while battery storage capacity rose nearly 60%, according to an analysis by the SUN DAY Campaign.
The group reported record solar performance in September, with utility-scale solar output up 36.1% from a year earlier and small-scale installations rising 12.7%. Combined solar sources supplied 9.7% of U.S. electricity that month, compared with 7.6% in the same period of the previous year.
For the first nine months of 2025, solar generation grew 29% and accounted for just over 9% of total U.S. electricity output, the analysis said. Utility-scale solar exceeded wind generation in September for the third consecutive month. The group also noted that year-to-date solar output topped hydropower by nearly 65%.
Wind generation supplied 9.8% of U.S. electricity in the first nine months of the year, up 1.3% from a year earlier. Combined wind and solar delivered 18.8% of total U.S. generation, while all renewable sources together provided 25.6%, second only to natural gas.
Between October 2024 and September 2025, utility-scale solar capacity increased by 31,619.5 MW and small-scale systems added 5,923.5 MW. Battery storage expanded by 13,808.9 MW, a 59.4% rise. Wind capacity grew by 4,843.2 MW, natural gas by 3,417.1 MW and nuclear by 46 MW. Coal capacity declined by 3,926.1 MW and petroleum-based generation fell by 606.6 MW.
The SUN DAY Campaign said total renewable capacity, including storage, increased by 56,019.7 MW over the 12-month period, while fossil fuel and nuclear capacity combined fell by 1,095.2 MW.
Commenting on the findings, SUN DAY Campaign executive director Ken Bossong said: “The Trump Administration’s efforts to jump-start nuclear power and fossil fuels are not succeeding. Capacity additions by solar, wind, and battery storage continue to dramatically outpace gas, coal, and nuclear … and by growing margins.”
