A recent analysis by the SUN DAY Campaign, using data from the Federal Energy Regulatory Commission (FERC) and the US Energy Information Administration (EIA), indicates that renewable energy sources have significantly expanded their role in the United States' electricity generation mix. As of mid-2024, renewables, including solar, wind, hydropower, biomass, and geothermal, now account for over 30% of the total utility-scale electrical generating capacity in the country. This milestone highlights the increasing dominance of clean energy sources in the US energy landscape, driven by steady growth in solar and wind power.
In addition to their growing share of capacity, renewable energy sources provided a quarter of the nation's electricity generation during the first seven months of 2024. Solar energy has played a particularly vital role in this growth, emerging as the largest source of new generating capacity for 11 consecutive months. This trend places solar energy on track to become the second-largest energy source in the US, surpassed only by natural gas, within the next three years.
FERC's latest “Energy Infrastructure Update,” which includes data through July 31, 2024, reports that 40 solar units, totaling 1,291 MW of capacity, were added in July, alongside two wind units contributing 141 MW. Combined, these renewable sources accounted for 76.1% of the total new generating capacity added during the month. The balance came from natural gas, which added 450 MW of new capacity.
The growth of solar and wind has been particularly pronounced in the first seven months of 2024. Solar capacity alone surged by 15 GW, while wind added an additional 2 GW. Smaller contributions came from hydropower, which added 212 MW, and biomass, which increased by 3 MW. Altogether, renewable energy sources contributed an overwhelming 89.7% of the total new generating capacity added to the grid during this period.
Solar energy, which accounted for 76.9% of all new generation capacity brought online between January and July 2024, saw its installed capacity grow by 81.2% compared to the same period in 2023. In July alone, solar made up 68.6% of all new capacity added, further cementing its role as the fastest-growing source of energy in the US.
Despite these gains, new natural gas capacity additions in the first seven months of 2024 amounted to just 9.6% of the capacity added during the same period in 2023, underscoring the sharp shift towards renewable energy. Similarly, biomass and hydropower saw more modest growth, with new capacity additions falling by 90% and 4.1%, respectively, compared to 2023 levels. Wind, while still expanding, also saw a decline, with capacity additions 17.8% lower than in the first seven months of 2023.
Solar power's dominance in new capacity additions has been consistent for nearly a year, with solar installations leading the way every month from September 2023 to July 2024. Wind energy has also been a critical contributor, taking second place for seven of these months. Together, the combined capacities of solar and wind now represent over one-fifth (20.9%) of the nation's total utility-scale generating capacity.
FERC's data primarily focuses on utility-scale installations larger than 1 MW, so the actual share of solar energy is likely even higher when considering the significant amount of small-scale solar, such as residential rooftop systems, which are not included in these figures. Factoring in these smaller systems would push the total share of solar and wind power closer to one-quarter of the country's overall generating capacity.
The latest capacity additions have propelled solar energy to fourth place among the largest sources of generating capacity in the US, surpassing nuclear power and trailing only natural gas, coal, and wind. Solar now holds a 9.1% share of total installed capacity, further expanding its lead over hydropower, which sits at 7.8%. Wind energy, meanwhile, maintains its position with an 11.8% share. When combined with smaller contributions from biomass (1.1%) and geothermal (0.3%), the total share of renewable energy now exceeds 30% of the country's installed utility-scale generating capacity.
Looking ahead, FERC's three-year forecast suggests continued strong growth in renewable energy capacity. Between August 2024 and July 2027, FERC expects 90 GW of solar capacity to be added, nearly four times the amount of wind capacity forecast for the same period (25 GW). Other renewable sources such as hydropower, geothermal, and biomass are also projected to grow, with expected additions of 1 GW, 400 MW, and 127 MW, respectively.
On the other hand, fossil fuel sources are expected to see a decline over the next three years. FERC's forecast anticipates a reduction in coal, natural gas, and oil capacity by 21 GW, 3 GW, and 2 GW, respectively. If FERC's projections hold true, by mid-2027, solar energy could account for more than one-seventh (15%) of the nation's installed utility-scale generating capacity, surpassing coal and closely trailing wind. Solar would solidify its position as the second-largest source of capacity, behind only natural gas, which is expected to account for 40.3% of the total.
Meanwhile, the combined capacities of all renewable energy sources, including small-scale solar, are on track to represent 36.5% of the country's total installed utility-scale generating capacity by 2027. This would put renewables within striking distance of natural gas, as the dominant energy source in the US. Furthermore, with the inclusion of small-scale solar installations, the total share of renewables could surpass 40%, with solar and wind together constituting more than three-quarters (76.1%) of the installed renewable capacity.
The EIA's “Electric Power Monthly” report, which provides data through July 31, 2024, further highlights solar's rapid growth. Utility-scale solar, including both photovoltaic and solar thermal systems, expanded by 29.7% in the first seven months of 2024, while small-scale solar grew by 16.8%. Together, these sources accounted for 7% of total US electricity generation during this period, with solar alone providing 7.4% of electricity generation in July.
Small-scale solar systems, which include residential rooftop installations, made up almost 30% of total solar generation, contributing 2% of the nation's electricity supply in the first seven months of the year.
The combination of wind and solar power provided 17.8% of the country's electricity generation during the first seven months of 2024, with the overall mix of renewables (including hydropower, biomass, and geothermal) growing by 9.1% compared to the same period in 2023. Renewables accounted for 24.9% of the nation's electricity production during this time, up from 23.9% in the first seven months of 2023.
As Ken Bossong, executive director of the SUN DAY Campaign, noted, “Renewable energy sources, led by solar, continue to expand their share of US generating capacity and electrical production. However, future growth may depend heavily on the results of the November elections,” highlighting the critical role of policy decisions in shaping the future of the US energy sector.
