US solar developers added 21.2 GW of solar through September 2025, according to FERC. This exceeds the 20 GW added through September in 2024.
Solar represents most of the power capacity added to the grid through September 2025, which totaled 28.2 GW.
Solar now represents 11.78% all U.S. installed generating capacity, said FERC. Natural gas has the largest share (42.2%), followed by coal (14.61%), wind (11.8%), nuclear (7.8%), and hydropower (7.6%).
