US August 2025: Winds calm, clouds in the Carolinas

The US' total operating capacity for wind energy stands at an impressive 157.4 GW, although August 2025 wind speeds declined 2.9%. Total operating capacity for solar energy has reached 144.0 GW, holding steady with no monthly solar radiation deviation. However, the 8.7 GW of capacity in North and South Carolina was more than 10% below average.

Wind

Texas has a commanding wind capacity of 43,877 MW, reporting a monthly deviation of negative 4.8%, though it remains slightly positive year to date at 0.4%. Meanwhile, Arizona boasts the most significant positive wind speed monthly deviation of 12.7%, on a capacity of 1,232 MW. On the flip side, New Hampshire grapples with the largest negative monthly deviation of 13.0% from its 213-MW capacity. In the year-to-date figures, 390-MW Utah stands out with a solid 7.0% increase, while Hawaii struggles with a year-to-date decline of 10.1% on 226 MW.

Among individual projects, the largest capacity belongs to the Great Prairie Wind Project in Texas, at 1,027 MW. That project reports stable monthly and year-to-date deviations of 0.4% and 0.2%, respectively. Although smaller at 1.9 MW, California's Foundation Scheid Vineyards Projects boasts the most significant monthly improvement, at 24.0%. Conversely, the Limestone Wind Project (Board Creek) in Texas faces challenges with a staggeringly low 26.6% monthly deviation.

Solar

Texas also leads the solar charge, with 30,110 MW, and a minor monthly decrease in solar radiation of 0.9%. Maine is basking in the sun with a remarkable positive monthly deviation of 17.9% from its 832-MW capacity. Florida is making strides with a year-to-date solar radiation increase of 2.7% on its 11,880-MW solar capacity, while New York lags with a 3.1% year-to-date deviation decrease from its 2,904 MW.

The Gemini Solar Project in Nevada continues to lead in capacity among solar projects with 690 MW, showing a slight monthly deviation of 0.1%. Meanwhile, Maine's BD Solar Ellsworth Project shines brightly with a 22.1% monthly increase, while South Carolina's Otarre Solar Park struggles with a negative 19.0% monthly deviation.

Solar radiation is the mean surface downward shortwave radiation flux, measured from the fifth-generation European Centre for Medium-Range Weather Forecasts reanalysis. This variable includes direct and diffuse solar radiation and is the model equivalent of global horizontal irradiance — the value measured by a pyranometer, a solar radiation measuring instrument. Wind speed is the value 100 meters above the ground from the same dataset. The data is available at quarter-degree latitudes and longitudes, with a spacing of slightly over 27.5 km. This analysis compares the August 2025 values with the 20-year average (2004–2023) for August.

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Data visualization by Zain Ullah.
This article was published by S&P Global Market Intelligence and not by S&P Global Ratings, which is a separately managed division of S&P Global.
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