June cloudy for US solar, but wind speeds near normal

As the summer heat blazes across the US, the latest energy data reveals a complex landscape for wind and solar power generation. In June 2025, the total operating capacity for wind energy reached an impressive 154.0 GW, with the monthly average winds up 0.7% compared to the 20-year normal. However, the year-to-date performance remained nearly flat, with a minimal deviation of negative 0.1%. Turning to solar energy, the US total operating capacity reached 138.0 GW in June, although it experienced a solar radiation monthly decline of 2.1%. Year to date, US-wide insolation is near normal, at 0.6% above average.

Wind: Texas continues to lead the charge

Texas leads in state wind capacity, boasting an astounding wind energy capacity of 42,478 MW. With monthly winds deviating 5.7% above the norm and a year-to-date increase of 0.9%, Texas remains at the heart of wind energy production in the US. Meanwhile, New York's 2,899 MW wind portfolio excelled in June, recording the highest monthly deviation, at 8.4% above the 20-year average.

On the flip side, West Virginia wind speeds were particularly sluggish, with a staggering monthly deviation of negative 16.1%, across the state's 592 MW of wind capacity. Hawaii breezes continue to struggle as well, with a year-to-date deviation of negative 11.4%.

Among individual projects, the 1,027-MW Great Prairie Wind Project in Texas experienced a modest monthly deviation of June winds at 1.5%. Monthly average winds in June for the FERMI (Val Verde Wind) (Rocksprings) project, also in Texas, achieved the highest positive monthly deviation, at 15.9%, while Montana's Stillwater Wind Project (Vivaldi Springtime Wind Project) faced the most considerable drop in average winds, with a monthly deviation of negative 24.1%.

In year-to-date average wind speeds, New York's Fenner Windpower project leads with a remarkable 13.4% jump compared to the 20-year average, while Hawaii's Kahuku Wind Power Project and the Na Pua Makani Wind Project both experienced the steepest decline, at negative 16.6%.

Solar: A slight dip

Texas topped charts with a 27,441-MW solar portfolio but faced a negative monthly radiation departure of 5.1%. Solar insolation in Oregon saw the highest monthly deviation at 7.2% and a year-to-date increase of 4.4% across the state's 1,239-MW photovoltaic fleet.

However, Minnesota struggled with a monthly average solar deviation of negative 11.2%, while New York's solar sector faced a year-to-date radiation departure of negative 7.6%.

The Gemini Solar Project in Nevada — the US' largest solar project, with a capacity of 690 MW — experienced a slight monthly dip in insolation at negative 1.4%. Four small projects in Oregon — the Tickle Creek Solar project, the Day Hill Solar Project, the Oregon SPI 18 - Clayfield Solar Plant and the Duus Solar Project — reported the highest positive monthly deviation at 15.0%. Wisconsin's New Auburn DPC Solar Project saw the most significant drop in average radiation, at negative 17.0%.

Five Oregon projects — the Firwood Solar Plant, the SSD Clackamas 1 Solar Power Plant, the Auburn Solar Facility, the DB Bull Run Facility (Sulus Solar 29), the Skyward Community Solar Project, the Boring Solar project, the Dunn Road Solar Project and the Sandy River Solar Project — lead in year-to-date average radiation, with a 9.1% increase. This is in contrast to a group of New York solar facilities, where year-to-date insolation is 11.7% below the 20-year average. These facilities include the Lenox Community Solar Project, the Lenox Renewables Solar Project, the Owlville Creek Solar Project, the Owlville Creek Solar 2 Farm, the Marathon Solar Farm South, the Madison County Solar Farm and the Marathon Solar Farm II North.

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 June 2025 values with the 20-year average (2004–2023) for June.

Gain access to our full news & research coverage and the industry-specific data that informs our insights

For wholesale prices and supply and demand projections, see the S&P Global Market Intelligence Power Forecast.For a complete, searchable listing of RRA's in-depth research and analysis, please go to the S&P Capital IQ Pro Energy Research Library.
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.
Adam Wilson contributed to this article.Regulatory Research Associates is a group within S&P Global Commodity Insights.
S&P Global Commodity Insights produces content for distribution on S&P Capital IQ Pro.