Canary Media

California was mostly solar-powered in May — a global first

2026-07-31 · 07:30 UTC ·Dan McCarthy ·2 min read

Brief

California’s power system hit a global milestone in May 2026 when solar — including both large-scale farms and rooftop PV — produced 51% of the state’s electricity, making it the first major economy to top 50% solar for an entire month, according to Ember and CAISO data reported by Canary Media. That achievement reflects rapid growth in grid-scale batteries (now ~16 GW) that shift abundant midday generation to evening hours and sometimes meet over 25% of nightly demand. Solar has outpaced natural gas in every month of 2026 leading up to May, squeezing fossil fuels from the mix. By contrast, a decade ago solar’s best month was ~17% and storage was only 61 MW, a change the article quantifies as a ≈26,129% increase in battery capacity.

Why it matters

Solar generated 51% of California’s electricity in May 2026 (counting utility-scale and rooftop arrays), the first time a major economy exceeded 50% solar for an entire month, per think tank Ember.

Key details

  • California Independent System Operator (CAISO) now has about 16 gigawatts of battery capacity, allowing midday solar to be shifted into the evening and enabling batteries to supply over one-quarter of demand for portions of the night.
  • Solar outproduced natural gas in every month of 2026 leading up to May; natural gas is now the only fossil fuel burned at appreciable levels in California power plants.
  • A decade ago solar’s best month was ~17% of generation and CAISO’s battery fleet was 61 megawatts — a storage increase the article reports as roughly 26,129% over ten years; Hungary reached 47% solar in June 2025 as a smaller-economy comparator.
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By Canary Media

No major economy had previously received over half its electricity from solar across an entire month. Thank the mild, sunny spring weather, and batteries.

See more from Canary Media’s “Chart of the Week” column.

While the Trump administration is busy pointing out that the sun doesn’t shine at night, solar is breaking records around the world, including in sunny California.

Solar panels produced 51% of California’s electricity in May, the first time the clean energy source surpassed the halfway mark for an entire month. The data counts both large-scale installations and the state’s bounty of rooftop arrays.

This isn’t just a milestone moment for California; it’s a milestone for the entire world. Think tank Ember says the state is the globe’s first major economy to cross the 50% threshold. (Hungary, at 47% in June 2025, is knocking at the door, though it has a far smaller GDP.)

Solar’s rise has helped California cut polluting energy sources out of its power mix. Natural gas is the only fossil fuel that California power plants burn at appreciable levels, and solar is steadily squeezing it out of the system. Case in point: Solar outproduced gas not only during its record month of May but throughout every month in 2026 leading up to it, too.

Solar could not have reached these heights alone. It needed batteries to get here — and California has that crucial energy storage in spades. The California Independent System Operator, which manages most of the state’s grid, now boasts 16 gigawatts of batteries that can shift abundant midday solar production to later in the evening. It’s not uncommon for batteries to meet over one-quarter of the state’s electricity demand for a portion of the night.

All this solar and storage would have been hard to imagine a decade ago. Back then, in its best month — also sunny, mild May — solar accounted for just 17% of electricity. That number is well above the current national average for solar, but a far cry from 51%. CAISO’s battery fleet, meanwhile, was a measly 61 megawatts. So, storage has grown by, uh … 26,129% over the last decade, a number so cartoonishly large that I’m almost hesitant to print it.

Expect California to see more months break the 50% threshold soon. And in the coming years, expect more states and countries to cross the halfway mark, too.

Canary Media’s “Chart of the Week” series is supported by *Amazon*. Amazon is known for speed and scale. That same approach drives their sustainability efforts. Guided by data and science, and powered by invention, Amazon works backward from ambitious targets to drive measurable progress. Every package delivered, every data center powered, every product designed is an opportunity to make tomorrow better.

Dan McCarthy

is a senior editor at Canary Media.

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