Solar power and battery storage were the leading sources of new electricity capacity in the United States over the past year, the Sun Day Campaign has said, citing data from the US Energy Information Administration (EIA).
In August alone, electricity generation by utility-scale solar installations increased by 29.5% compared to the corresponding month a year earlier, while ‘small-scale’ solar generation (such as on rooftops), increased by 10.8%.
Combined, solar grew by 24.7% in August, compared to the same month a year earlier, providing 9.5% of the US’s electrical output during the month, up from 7.6% a year ago.
During the first eight months of the year, utility scale solar generation was up 35.7%, with small-scale solar generation rising by 11.0%, the data showed.
Elsewhere, wind power contributed 10.2% of total electricity generation in the US for the first eight months of 2025, which was 2.6% higher than the same period last year.
Renewable electricity generation
Together, wind and solar supplied close to a fifth (19.1%) of US electricity generation during the first eight months of this year, surpassing both coal and nuclear power. This compares to 17.2% in the first eight months of last year.
Total renewable generation, including wind, solar, hydropower, biomass, and geothermal, reached 26.1% of national output, up from 24.5% a year earlier.
Battery storage
Battery storage capacity in the US has expanded by 63.9% over the past year, adding 13.4 gigawatts of new capacity.
Planned additions to the battery storage capacity network are expected to account for more than 20 gigawatts next year.
Over the past year, natural gas capacity rose by 3.3 gigawatts and nuclear capacity by 46 megawatts, while coal and petroleum-based electricity generation together declined by more than 4.8 gigawatts.
“The Trump Administration and its Republican supporters in Congress may slow renewable energy growth a bit,” noted the Sun Day Campaign’s executive director Ken Bossong. “However, EIA’s data reinforce the conclusion that the transition to solar, wind, other renewables and storage continues, is accelerating, and has become inevitable.” Read more here.
