Over the Past Year, U.S. Solar-Generated Electricity Grew 37% While Battery Storage Expanded by 64% as 55.4-GW of New Renewables + Battery Capacity Came On-Line

A review by the SUN DAY Campaign of data just released by the U.S. Energy Information Administration (EIA) reveals that solar and battery storage have dominated growth among competing energy sources while fossil fuels and nuclear power have stagnated.

Solar electrical generation set new records in August and the first two-thirds of 2025:

EIA’s latest monthly "Electric Power Monthly" report (with data through August 31, 2025), once again confirms that solar is the fastest growing among the major sources of U.S. electricity.

In August alone, electrical generation by utility-scale solar (i.e., >1-megawatt (MW)) ballooned by almost one-third (29.5%) compared to August 2024 while “estimated” small-scale (e.g., rooftop) solar PV increased by 10.8%. Combined, they grew by 24.7% and provided nearly one-tenth (9.5%) of the nation’s electrical output during the month, up from 7.6% a year ago. [1]

Moreover, utility-scale solar thermal and photovoltaic expanded by 35.7% while that from small-scale systems rose by 11.0% during the first eight months of 2025 compared to the same period in 2024. The combination of utility-scale and small-scale solar increased by almost a third (28.8%) and was over 8.9% (utility-scale: 6.7%; small-scale: 2.2%) of total U.S. electrical generation for January-August - up from 7.1% a year earlier.

As a consequence, solar-generated electricity year-to-date (YTD) easily surpassed - by over 58% - the output of the nation’s hydropower plants (5.6% of total generation). In August alone, solar-generated electricity more than doubled the output of the nation’s hydropower plants. In fact, in both August and YTD, solar produced more electricity than hydropower, biomass, and geothermal combined. [2]

Moreover, for the second consecutive month, utility-scale solar generated more electricity than the nation’s wind farms – by 4% in July and by 15% in August. Including small-scale systems, solar has out-produced wind four months in a row and by almost 50% during August. [3]

Wind has also made a strong showing YTD:

Wind turbines across the U.S. produced over a tenth (10.2%) of U.S. electricity in the first eight months of 2025 – an increase of 2.6% compared to the same period a year earlier and 80% more than that produced by the nation’s hydropower plants.

Wind + solar are almost one-fifth of total U.S. electrical generation – a larger share than that provided by either coal or nuclear power:  

During the first eight months of 2025, electrical generation by wind plus utility-scale and small-scale solar provided almost a fifth (19.1%) of the U.S. total, up from 17.2% during the first two-thirds of 2024.

Further, the combination of wind and solar provided 16.2% more electricity than did coal during the first eight months of this year, and 11.7% more than the nation’s nuclear power plants. In fact, as solar and wind expanded, nuclear-generated electricity dropped by 0.7%.

Electrical output YTD by the mix of all renewables was over 26% of total U.S. generation:

The mix of all renewables (i.e., wind and solar plus hydropower, biomass and geothermal) produced 9.0% more electricity in January-August than they did a year ago and provided (26.1%) of total U.S. electricity production compared to 24.5% twelve months earlier.

Renewables’ share of electrical generation is now second to only that of natural gas whose electrical output actually dropped by almost 4.1% during the first eight months of 2025.  

During the past year, solar and battery storage have dominated capacity additions, coupled with a strong showing by wind:

Between September 1, 2024 and August 31, 2025, utility-scale solar capacity grew by 31,706.5-MW while an additional 5,718.1-MW was provided by small-scale solar. EIA foresees continued strong solar growth, with even more utility-scale solar capacity - 34,325.8-MW - being added in the next twelve months.

Strong growth was also experienced by battery storage which grew by 63.9% during the past year and added 13,377.5-MW of new capacity. In the course of the past year, battery storage actually surpassed pumped hydro storage (PHS) - in October 2024 - and now accounts for 50% more storage capacity than PHS. EIA also notes that planned battery capacity additions during the next year total 20,179.8-MW.

Wind also made a strong showing during the past twelve months, adding 4,791.9-MW, while planned capacity additions over the next year total 9,650.1-MW.

On the other hand, natural gas capacity increased by only 3,337.7-MW and nuclear power added a mere 46.0-MW. Meanwhile, coal capacity plummeted by 4,185.1-MW and petroleum-based capacity fell by an additional 658.7-MW.

Thus, during the past year, renewable energy capacity, including battery storage and small-scale solar, ballooned by 55,419.6-MW while that of all fossil fuels and nuclear power combined actually declined by 1,486.3-MW. [4]

"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."

EIA | https://www.eia.gov/electricity/monthly

[1] In its “Electric Power Monthly” report, EIA refers to small-scale or distributed solar as “Estimated Small Scale Solar Photovoltaic.” Unless otherwise indicated, all calculations presented in this release include electrical generation by small-scale solar which EIA estimates to have totaled 65,834-GWh in January-August 2025 and 9,319-GWh in August alone. Utility-scale solar totaled 207,722-GWh for the first eight months of 2025 and 31,501-GWH in just August.

[2] In January-August 2025, wind produced 311,246-GWh (10.2%) of total U.S. electrical generation while utility-scale and small-scale solar combined produced 273,555-GWh (8.9%), hydropower produced 172,751-GWh (5.6%), biomass produced 30,971-GWh (1.0%), and geothermal produced 10,499-GWh (>0.3%).

[3] In August alone, wind produced 27,297-GWh while utility-scale solar produced 31,501-GWh. The combination of utility-scale and small-scale solar totaled 40,820-GWh.

[4] EIA notes that its capacity data is “summer capacity”.