Washington DC – A review by the SUN DAY Campaign of data just released by the Federal Energy Regulatory Commission (FERC) reveals that the mix of renewable energy sources (i.e., biomass, geothermal, hydropower, solar, wind) accounted for more than 90% of total U.S. electrical generating capacity added in 2024. Solar alone accounted for over 81% of the new capacity. Moreover, December was the sixteenth month in a row in which solar was the largest source of new capacity.
Renewables were 86.9% of new generating capacity in December and 90.5% in 2024:
In its latest monthly “Energy Infrastructure Update” report (with data through December 31, 2024), FERC says 105 “units” of solar totaling 4,369 megawatts (MW) were placed into service in December along with two units of wind (324-MW) and two units of biomass (45-MW). Combined they accounted for 86.9% of all new generating capacity added during the month. Natural gas provided the balance: 717-MW. [1]
During the full 2024 calendar year, solar and wind added 30,816-MW and 3,128-MW respectively. Combined with 213-MW of hydropower, 51-MW of biomass, and 29-MW of geothermal steam, renewables were 90.5% of capacity added. The balance consisted of the 1,100 Vogtle-4 nuclear reactor in Georgia plus 2,428-MW of natural gas, 13-MW of coal, 11-MW of oil, and 28-MW classified as “other.”
Solar was 80.1% of new capacity in December and 81.5% during 2024:
Solar accounted for 81.5% of all new generating capacity placed into service in 2024 – 50% more than the solar capacity added in 2023.
In December alone, solar comprised 80.1% of all new capacity added.
New solar capacity added in 2024 is almost nine times that added by natural gas and nuclear power combined.
Solar has now been the largest source of new generating capacity added each month for sixteen months straight: September 2023 – December 2024.
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. [2]
Solar plus wind are now almost 22% of U.S. utility-scale generating capacity; all renewables combined are 31%:
New wind accounted for much of the balance (8.3%) of capacity additions which is more than either the new natural gas capacity (6.4%) or nuclear power capacity (2.9%).
Taken together, the installed capacities of just solar (10.2%) and wind (11.7%) now constitute more than one-fifth (21.9%) of the nation’s total available installed utility-scale generating capacity.
However, approximately 30% of U.S. solar capacity is in the form of small-scale (e.g., rooftop) systems that is not reflected in FERC’s data. [3] Including that additional solar capacity would bring the share provided by solar + wind closer to a quarter of the nation’s total.
With the inclusion of hydropower (7.7%), biomass (1.1%) and geothermal (0.3%), renewables now claim a 31.0% share of total U.S. utility-scale generating capacity. If small-scale solar capacity is included, renewables are now about one-third of total U.S. generating capacity.
Solar’s share of U.S. generating capacity is now 10x greater than a decade ago while wind’s is more than double:
As noted, by the end of 2024, solar and wind accounted for 10.2% and 11.7% respectively of all installed utility-scale generating capacity in the U.S. while the mix of all renewables (i.e., including hydropower, biomass, and geothermal) accounted for 31.0%.
A year earlier (i.e., December 2023), FERC reported that solar and wind were 7.9% and 11.7% of installed capacity while the mix of all renewables provided 29.0%.
Five years ago (i.e., December 2019), FERC released data showing solar and wind to be 3.5% and 8.5% of total capacity while all renewables combined were 22.1%.
A decade ago (i.e., December 2014), FERC reported that solar and wind were 1.0% and 5.5% of total capacity while the combination of all renewables accounted for 16.6% of capacity.
Solar’s share of installed U.S. generating capacity is greater than either nuclear power or hydropower:
The latest capacity additions have brought solar’s share of total available installed utility-scale (i.e., >1-MW) generating capacity up to 10.2%, further expanding its lead over nuclear power (7.8%) as well as hydropower (7.7%).
Installed utility-scale solar has now moved into fourth place – behind natural gas (43.0%), coal (15.3%) and wind (11.7%) – for its share of generating capacity.
Solar will soon become the second largest source of U.S. generating capacity:
FERC reports that net “high probability” additions of solar between January 2025 and December 2027 total 91,558-MW – an amount almost four times the forecast net “high probability” additions for wind (23,601-MW), the second fastest growing resource. FERC also foresees growth for hydropower (1,345-MW), geothermal (90-MW), and biomass (61-MW).
Taken together, the net new “high probability” capacity additions by all renewable energy sources would total 116,655-MW with solar comprising over 78% and wind providing another 20%.
On the other hand, there is no new nuclear capacity in FERC’s three-year forecast while coal, oil, and natural gas are projected to contract by 23,925-MW, 2,293-MW, and 833-MW respectively.
If FERC’s current “high probability” additions materialize, by January 1, 2028, solar will account for nearly one-sixth (16.1%) of the nation’s installed utility-scale generating capacity. That would be greater than either coal or wind (both 12.6%) and substantially more than either nuclear power or hydropower (both 7.3%).
In fact, assuming current growth rates continue, the installed capacity of utility-scale solar is likely to surpass coal and wind within the next two years, placing solar in second place for installed generating capacity – behind only natural gas.
Meanwhile, the mix of all renewables is now adding about two percentage points each year to its share of generating capacity. Thus, by January 1, 2028, renewables would account for 37.3% of total available installed utility-scale generating capacity – rapidly approaching that of natural gas (40.2%) – with solar and wind constituting more than three-quarters of the installed renewable energy capacity.
The combined capacities of all renewables, including small-scale solar, are on track to exceed natural gas within three years:
As noted, FERC’s data do not account for the capacity of small-scale solar systems. If that is factored in, within three years, total U.S. solar capacity (i.e., small-scale plus utility-scale) could surpass 320-GW. In turn, the mix of all renewables would then exceed 40% of total installed capacity while natural gas’ share would drop to about 37%.
Moreover, FERC reports that there may actually be as much as 222,443-MW of net new solar additions in the current three-year pipeline in addition to 68,815-MW of new wind, 8,659-MW of new hydropower, 199-MW of new geothermal, and 127-MW of new biomass. By contrast, net new natural gas capacity potentially in the three-year pipeline totals just 19,438-MW. Thus, renewables’ share could be even greater by early 2028.
“For more than a decade, renewable energy sources – led by solar – have dominated growth in U.S. generating capacity,” noted the SUN DAY Campaign’s executive director Ken Bossong. “Consequently, efforts by the Trump Administration to reverse this trend are both illogical and likely to fail.”
