Solar energy dominated U.S. grid capacity additions in the first half of 2025, accounting for 75% of new large-scale projects, according to data released by the Federal Energy Regulatory Commission (FERC) on Thursday. Large-scale solar projects are defined as those exceeding 1 megawatt (MW) in capacity.
The report shows 14.5 gigawatts (GW) of solar came online during the period, out of a total 19.4 GW of new generating capacity. Wind added 3.1 GW, natural gas 1.7 GW, and 57 MW of coal capacity was retired. FERC noted that while natural gas remains the dominant source of total U.S. generating capacity at 42.3%, solar now represents 11.3%, ahead of nuclear at 7.8% and hydropower at 7.6%.
Looking ahead, FERC projects solar will continue to lead capacity growth over the next three years, with 92.6 GW expected to come online, far exceeding projected additions from wind (23.3 GW) and natural gas (22.5 GW). Coal retirements are forecasted to total over 25 GW during the same period.
Notable solar projects completed in June 2025 include the 417.7 MW Ash Creek Solar Project in Hill County, Texas, the 300 MW Box Canyon Solar Project in Pinal County, Arizona, and the 250 MW Morris Solar Project in Adair County, Missouri. Other large-scale completions included Mercury Solar & Storage projects in Texas totaling 412.2 MW, the 200 MW Big Star Solar & Storage Project in Bastrop County, Texas, and the 199 MW Speedway Solar Project in Shelby County, Indiana. Several smaller projects, ranging from 5 MW to 130.6 MW, were also completed across states including Michigan, Utah, Nevada, Maryland, Ohio, New York, Massachusetts, and Tennessee.
FERC’s data underscores solar’s growing role in the U.S. energy transition, highlighting its prominence in near-term capacity expansions and its continued contribution to decarbonizing the nation’s electricity grid
