Solar was the largest source of new power generating capacity the past 12 months

Solar-powered generation made up 99.6% of US capacity additions in August, marking the 12th month in a row where solar was the largest source of new capacity, according to Federal Energy Regulatory Commission data.

During the first eight months 2024, solar and wind added 16.546 GW and 2.27 GW respectively, a review of FERC’s latest monthly Energy Infrastructure Update by the nonprofit SUN DAY Campaign showed. Combined with 212 MW of hydropower and 6 MW of biomass, renewables made up 90.1% of all electrical generating capacity added.

That trend fit expectations of S&P Global Commodity Insights, said Sam Huntington, director on the North American power team with S&P Global Commodity Insights.

“We’re targeting about 36 GW of front-of-meter solar this year, with another 9 GW of behind-the-meter,” Huntington said about solar capacity additions. “So, as a resource class it is just way, way ahead of everything else. And this trend should continue through at least the end of the decade as we expect FOM solar to top 30 GW every year between now and then.”

Solar is on track to become the second-largest source of US generating capacity, the SUN DAY Campaign said. FERC’s “high probability” scenario shows solar additions reaching 91.266 GW by Sept. 1, 2027, which would make solar capacity 15.2% of the nation’s installed utility-scale generating capacity and second only behind only natural gas at 40.3%. At the same time, coal retirements would reach 21.377 GW, followed by natural gas retirements of 14.794 GW.

“Meanwhile, the mix of all renewables would account for 36.4% of total available installed utility-scale generating capacity - rapidly approaching that of natural gas - with solar and wind constituting more than three-quarters of the installed renewable energy capacity,” the SUN DAY Campaign said.

Solar soars

During the first eight months 2024, solar added 16,546 MW, while wind added 2,270 MW, according to the FERC data. Combined with 212-MW of hydropower and 6-MW of biomass, renewables made up 90.1% of the generating capacity added. The balance consisted of the 1,100 Vogtle-4 nuclear reactor in Georgia, 977 MW of gas, 11 MW of oil, and 3 MW of other resources.

The amount of solar added January through August was more than double the solar capacity added a year ago. However, about 30% of US solar capacity is in the form of small-scale systems that is not reflected in FERC’s data, according to the SUN DAY Campaign.

“Every month, for a full year now, solar has led the pack in providing new US generating capacity," the SUN DAY Campaign's executive director Ken Bossong said in an Oct. 21 statement. "And it is poised to continue dominating capacity additions for at least the next three years."

Within three years, total US solar capacity is likely to surpass 300 GW and the mix of all renewables would then exceed 40% of total installed capacity, while natural gas’ share would drop to about 37%, according to the SUN DAY Campaign.