“Adjusting for the differences in capacity factors among solar, nuclear power, and natural gas, the new solar capacity added in 2024 is likely to generate seven times as much electricity as the new nuclear capacity and about five times as much as might be expected from the new natural gas capacity,” SUN DAY explains

The SUN DAY Campaign based its calculations on FERC data, which show that 105 units of solar power went into service in December of 2024 alone, for a total of 4.369 gigawatts. Between wind, solar, and biomass, renewable energy accounted for 86.9% of added capacity in December, with natural gas making up the rest with a relatively small contribution of 717 megawatts.

“Solar’s share of U.S. generating capacity is now 10x greater than a decade ago while wind’s is more than double,” SUN DAY emphasizes, noting that FERC expresses a “high probability” that new additions of solar capacity will total more than 9.1 gigawatts between now and December 2027, with wind coming in second with more than 2.3 gigawatts.