Solar energy has topped all U.S. generating capacity additions for the 25th consecutive month, according to a review of new Federal Energy Regulatory Commission (FERC) data by the SUN DAY Campaign.
In September, solar accounted for 98% of new capacity, the group said. FERC’s latest update shows that 48 solar units with a combined 2,014 megawatts (MW) were placed into service during the month.
Utility-scale solar additions have reached 21,257 MW across 567 units so far this year, making up more than 75% of all new U.S. generation capacity. Total utility-scale solar capacity grew from 91.82 gigawatts (GW) in September 2023 to 158.43 GW in September 2025, the review found.
Wind installations added 3,724 MW in the first nine months of 2025, outpacing the 3,161 MW added by natural gas. Overall, renewables accounted for more than 88.5% of new capacity year-to-date, including smaller contributions from hydropower and biomass.
Utility-scale solar now represents 11.78% of installed U.S. capacity, nearly equal to wind at 11.80%. Combined, wind and solar account for 23.58% of total U.S. utility-scale capacity.
FERC’s “high probability” forecast suggests solar could add an additional 90,614 MW over the next three years, compared with 23,093 MW for wind.
SUN DAY Campaign executive director Ken Bossong said recent political rhetoric does not alter underlying market trends. “In an effort to deny reality, the Trump Administration has just announced a renaming of the National Renewable Energy Laboratory (NREL) in which it has removed the word ‘renewable’,” he said. “However, FERC’s latest data show that no amount of rhetorical manipulation can change the fact that solar, wind, and other renewables continue on the path to eventual domination of the energy market.”
