SUN DAY CAMPAIGN
Solar Dominates for the 25th Consecutive Month Providing 98% of New U.S. Electrical Generating Capacity in September and >75% Year-to-Date,

Highlights

• FOR 25 MONTHS STRAIGHT, SOLAR HAS PROVIDED MORE NEW GENERATING CAPACITY THAN ANY OTHER ENERGY SOURCE
• YEAR-TO-DATE, SOLAR WAS >75% OF NEW U.S. ELECTRICAL CAPACITY AND 98% IN SEPTEMBER ALONE
• SOLAR IS ON TRACK TO BE A FIFTH OF TOTAL CAPACITY WITHIN THREE YEARS; MIX OF RENEWALES LIKELY TO TOP 40%

A review by the SUN DAY Campaign of newly-published data from the Federal Energy Regulatory Commission (FERC) reveals that solar accounted for over three-quarters of U.S. electrical generating capacity added in the first nine months of 2025. In September alone, solar provided 98% of new capacity, marking 25 consecutive months in which solar has held the lead every month among all energy sources. Year-to-date (YTD), solar and wind have each added more new capacity than did natural gas. The mix of all renewables remains on track to exceed 40% of installed capacity within three years; solar alone may be 20%.

Solar was 98% of new generating capacity in September and 75% year-to-date:

In its latest monthly "Energy Infrastructure Update" report (with data through September 30, 2025), FERC says 48 "units" of solar totaling 2,014 megawatts (MW) were placed into service in September, accounting for 98% of all new generating capacity added during the month. Oil provided the balance (40-MW).

The newest facilities include seven solar farms, each with a capacity of 100-MW or more: 250.0-MW Sebree Solar Project in Henderson County, KY; 150.0-MW Black Hollow Sun LLC in Pueblo County, CO; 150-MW Eldorado Solar Project in Saline County, IL; 150-MW Milagro Solar & Battery Project on Dona Ana County, NM; 149.0-MW Daggett-1 Project in San Bernadino County, CA; 115.0-MW Escape Solar Plant in Lincoln County, NV; and 100.0-MW Bluebird Solar Project in Harrison County, KY.

The 567 units of utility-scale (i.e., >1-MW) solar added during the first nine months of 2025 total 21,257-MW and were more than three-quarters (75.3%) of the total new capacity placed into service by all sources. Solar capacity added YTD is 6.5% more than that added during the same period a year earlier.

Solar has now been the largest source of new generating capacity added each month for 25 months straight: September 2023 - September 2025. During that period, total utility-scale solar capacity grew from 91.82 gigawatts (GW) to 158.43-GW. No other energy source added anything close to that amount of new capacity. Wind, for example, expanded by 11.07-GW while natural gas' net increase was just 4.60-GW. [1]

New wind capacity was greater than that of natural gas:

Between January and September, new wind has provided 3,724-MW of capacity additions - an increase of 28.6% compared to a year earlier and more than the new capacity provided by natural gas (3,161-MW). Wind thus accounted for 13.2% of all new capacity added during the first nine months of 2025.

Renewables were almost 89% of new capacity added year-to-date:

YTD, wind plus solar (plus 4-MW of hydropower and 6-MW of biomass) accounted for over 88.5% of all new generating capacity while natural gas added just 11.2%. The balance of net capacity additions came from oil (63-MW) and waste heat (17-MW).

Solar + wind are a quarter of U.S. generating capacity; all renewables combined are over a third:

Utility-scale solar's share of total installed capacity (11.78%) is now virtually tied with that of wind (11.80%). If recent growth rates continue, utility-scale solar capacity should surpass that of wind in FERC's next "Energy Infrastructure Update" report.

Taken together, wind and solar constitute nearly one-fourth (23.58%) of the U.S.'s total available installed utility-scale generating capacity.

Moreover, more than 25% of U.S. solar capacity is in the form of small-scale (e.g., rooftop) systems that are not reflected in FERC's data. [2] Including that additional solar capacity would bring the share provided by solar + wind to more than a quarter of the nation's total.

With the inclusion of hydropower (7.59%), biomass (1.05%) and geothermal (0.31%), renewables currently claim a 32.53% share of total U.S. utility-scale generating capacity. If small-scale solar capacity is included, renewables are now more than one-third of total U.S. generating capacity.

Solar is on track to become the second largest source of U.S. generating capacity:

FERC reports that net "high probability" net additions of solar between October 2025 and September 2028 total 90,614-MW - an amount almost four times the forecast net "high probability" additions for wind (23,093-MW), the second fastest growing resource.

FERC also foresees net growth for hydropower (566-MW) and geothermal (92-MW) but a decrease of 126-MW in biomass capacity.

Meanwhile, natural gas capacity would expand by 6,667-MW and nuclear power would add just 335-MW, while coal and oil are projected to contract by 24,011-MW and 1,587-MW respectively.

Taken together, the net new "high probability" net utility-scale capacity additions by all renewable energy sources over the next three years - i.e., the Trump Administration's remaining time in office - would total 114,239-MW. On the other hand, the installed capacity of fossil fuels and nuclear power combined would shrink by 18,596-MW.

Should FERC's three-year forecast materialize, by mid-fall 2028, utility-scale solar would account for 17.3% of installed U.S. generating capacity - more than any other source besides natural gas (39.9%). Further, the capacity of the mix of all utility-scale renewable energy sources would exceed 38%. Inclusion of small-scale solar - assuming it retains its 25% share of all solar - could push solar's share to over 20% and that of all renewables to over 41% while that of natural gas would drop to less than 38%.

In fact, the numbers for renewables could be significantly higher.

FERC notes that "all additions" (net) for utility-scale solar over the next three years could be as high as 232,487-MW while those for wind could total 65,658-MW. Hydro's net additions could reach 9,927-MW while geothermal and biomass could increase by 202-MW and 32-MW respectively. Such growth by renewable sources would swamp that of natural gas (29,859-MW).

"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'," noted the SUN DAY Campaign's executive director Ken Bossong. "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." 

Source:  

FERC's 7-page "Energy Infrastructure Update for September 2025" was posted on December 1, 2025. The link to the full report can be found at: https://cms.ferc.gov/media/energy-infrastructure-update-september-2025.

For the information cited in this update, see the tables entitled "New Generation In-Service (New Build and Expansion)," "Total Available Installed Generating Capacity," and "Generation Capacity Additions and Retirements."

FERC notes: "Data derived from Velocity Suite, Hidachi Energy, and Yes Energy. The data may be subject to update."

Notes:   

[1] Generating capacity is not the same as actual generation. Fossil fuels and nuclear power usually have higher "capacity factors" than do wind and solar. The U.S. Energy Information Administration (EIA) reports capacity factors in calendar year 2024 for nuclear power, combined-cycle natural gas plants and coal were 92.3%, 59.7%, and 42.6% respectively while those for wind and utility-scale solar PV were 34.3% and 23.4%. See Tables 6.07.A and 6.07.B in EIA's most recent "Electric Power Monthly" report. 

[2] While FERC does not provide capacity data for small-scale solar, the U.S. EIA does. In its latest "Electric Power Monthly" report issued on November 25, 2025, EIA reported that as of September 30, 2025, installed solar capacity totaled 199,085.1-MW of which 57,506.9-MW (i.e., 28.9%) was provided by small-scale solar. See table 6.1 at https://www.eia.gov/electricity/monthly/epm_table_grapher.php?t=table_6_01

The SUN DAY Campaign is a non-profit research and educational organization founded in 1992 to support a rapid transition to 100% reliance on sustainable energy technologies as a cost-effective alternative to nuclear power and fossil fuels and as a solution to climate change.