US Solar Beat Wind for Four Months — Now Comes the Winter Test

For four straight months this summer, the sun out-generated the wind on the American power grid. According to the US Energy Information Administration's Electric Power Monthly, released on 23 October, solar power produced more electricity than wind in every month from May through August 2026. In August, solar supplied 49.206 billion kilowatthours against wind's 33.317 billion; in July the gap was wider still, 51.956 billion against 31.889 billion. It is the kind of streak that invites a big claim, and the big claim would be wrong — at least on the evidence so far.

The scoreboard for the year as a whole still favours wind. Across January to August, wind generated 333.367 billion kilowatthours and solar 329.119 billion, a lead of just 4.248 billion for wind. Four summer months do not make a year, and the reason is the calendar: solar output peaks with long summer days, while wind's strongest season is the cold half of the year. The race is close precisely because the two technologies take turns.

What makes this year different from previous ones is the slope. In the first eight months of 2026, utility-scale solar generation grew 20.0% compared with the same period in 2025, small-scale solar grew 12.0%, and wind grew 7.8%. Between September 2025 and August 2026, developers added 27,141.7 megawatts of utility-scale solar and 6,526.1 megawatts of small-scale solar, against 9,979.1 megawatts of wind. BloombergNEF expects 89 gigawatts of solar, wind and storage capacity to be added in the United States in 2026 alone, with solar accounting for 48.9 gigawatts. And solar is increasingly paired with batteries: as of September 2026, over 16% of utility-scale solar capacity added this year is co-located with operating battery storage, up from 2% in 2017, with reported plans pushing that share toward 19% for the full year. Storage matters because it lets solar power earned at noon count in the evening, instead of being curtailed when the grid has more sunshine than it can use.

There is a precedent that should temper the excitement. In 2025, solar beat wind in July, August and September too — by 4%, 15% and 9% on a utility-scale basis, and by more than 40% in September once rooftop systems were included — and wind still won the year comfortably. Winter reasserts itself: days shorten, the sun weakens, and wind picks up. There is also an accounting detail worth stating plainly. The EIA's solar figure includes estimated small-scale rooftop generation, while its wind figure is utility-scale only, so the comparison flatters solar slightly. None of that erases the streak, but it explains why a summer lead is not an annual title.

So where does that leave the question everyone actually wants answered — does solar win 2026? My honest answer is: probably not, but it is close enough to be worth calling. The September data, due on 24 November, will very likely flip the year-to-date lead to solar; September 2025 saw solar beat wind by more than 40% including rooftop systems, and the solar fleet is much bigger now. The hard part is October to December. For solar to hold on, the winter wind advantage would have to come in narrower than about 15 billion kilowatthours, against roughly 30 billion in a normal year. A record fourth-quarter build-out could help — developers have 26.5 gigawatts of solar scheduled for September to December, though the EIA's own forecast expects only about 16 gigawatts of it to actually arrive — and so could a calm winter. I put the chance at 25%: a genuine underdog bet, not a coin flip and not a fantasy.

The monthly gaps for May (+5.987) and June (+7.534) are shown in the chart above.

What to watch next is simple. On 24 November the EIA publishes September data, which should show whether solar took the year-to-date lead for the first time. After that, everything depends on how much of the scheduled fourth-quarter solar actually gets connected, and on whether winter winds are merely strong or exceptional. Capacity is not generation — a panel's nameplate tells you nothing about what it delivers in December — but generation is catching up with capacity fast. Whether 2026 is the year solar finally wins, or the year it came within a few billion kilowatthours and lost, either result will mark how far the transition has come.