Solar now out-generates nuclear by 13%. Grids are the next bottleneck

Over the 12 months to September 2026, solar generated 13% more electricity than nuclear worldwide, according to BBC analysis of data from the UK energy think tank Ember. Solar first edged past nuclear in 2025, and in 2026 it is expected to reach about 10% of global power, up from roughly 1% a decade ago. Nuclear's output has stayed roughly flat since 2000; solar's has grown some 2,700-fold.

Why the forecasts keep missing

Oxford energy policy professor Jan Rosenow says mainstream outlooks, including those from the International Energy Agency, 'assumed linear growth and slowly falling costs, and got both wrong'. Solar met three-quarters of the growth in global electricity demand in 2025. Solar became the cheapest electricity in history in 2020, and a sharp fall in panel prices in 2023-24 pushed it further. Ember co-founder Dave Jones says a panel costs 'well under $100' and keeps generating for 30 to 40 years with no input. Rosenow credits Chinese manufacturing scale and current overcapacity for record-low module prices.

The mechanism: why cheap panels were not enough

A panel only produces when the sun shines, so its electricity is worth most when paired with a battery that stores midday output for the evening. Batteries have had their own cost collapse. Rosenow says solar plus storage is now routinely cheaper than new fossil plants in sunny regions. In California, solar and batteries met on average over a quarter of demand during the 19:00-21:00 evening peak in the first half of 2026.

Two gaps remain. Storage across seasons, cloudy spells and monsoons is unsolved, according to both Rosenow and Jones. And the grid itself, the wires and the rules that move power, has to absorb all of this. Rosenow puts it bluntly: the limits are now grids, storage and the pace of electrifying demand, not panels or cost.

Who gains, who is exposed

The clearest winners are places with costly, unreliable grids. Pakistan went from under 2% solar electricity in 2019 to 24%, with solar becoming its largest source in 2025, largely funded from household pockets rather than loans, Jones says. Africa is installing about 100,000 panels a day, and escalating diesel prices have tilted the economics further against home generators. In India, new solar met 60% of the rise in power demand over the past two years.

The exposed are less obvious. Fossil-fuel importers face less demand growth to sell into: Jones notes that clean electricity growth has directly meant fewer coal plants being built. Utilities in places where households can act without waiting for them, as Rosenow puts it, lose their role as gatekeeper. And everyone depends on one supplier: Rosenow's caveat is that if Chinese panels become difficult to import, the growth will not happen at speed.

What It Means for Businesses and People

For operators, the source supports a few concrete points. In the US, data centres and electrification mean power demand is growing for the first time in decades, per Alicia Zhao of the University of Maryland, and renewables already make up over 90% of new US capacity. She says solar remains among the cheapest new power in the US even with tariffs, which raise costs and slow expansion. Julia Souder of the Long Duration Energy Storage Council warns that adding massive new loads without built-in flexibility 'creates a fragile system'. The IEA expects solar generation in 2030 to be double 2025's level, overtaking hydro as the world's third-largest source.

Questions You Should Be Asking

• If our power plan assumes steady, linear solar growth, what happens when the forecasts have been wrong in the same direction year after year?
• How much of our supply chain, or our energy supplier's, depends on Chinese panel imports, and what is the fallback if they become hard to get?
• Does our new load, whether data centres or electrified fleets, come with built-in flexibility, or are we adding the fragility Souder describes?
• Who pays for the grid upgrades and storage that Rosenow says are now the real constraint, and does our site get connected before the queue grows?
• Does a quoted cost for solar include batteries for the evening peak, or only the panels?

What To Watch Next

Jones says global solar growth may slow in 2026 for the first time, because China changed its support regime and installations bunched into 2025. Excluding China, he says more panels are being installed this year than last. If non-China installations keep climbing while China's cools, the story is genuinely global; if they stall, the threshold crossing was partly a Chinese policy artefact.