TL;DR
Prime made for students and young adults
- Fast, free delivery for dorm and study essentials
- Prime Video and Amazon Music included
- Member-only deals
The World Nuclear Industry Status Report 2026 says solar generated more electricity globally than nuclear in 2025, the first time it has done so annually. Solar and wind each outproduced nuclear in every month from March 2025 through June 2026, while generation growth and new capacity remained concentrated in renewables. The findings are based on the report’s estimates; it says other data put 2025 solar additions higher still.
Global solar power generation exceeded nuclear output in 2025 for the first time, according to the World Nuclear Industry Status Report (WNISR) 2026, which also says wind and solar each generated more electricity than nuclear in every month from March 2025 through June 2026. The milestone reflects the rapid expansion of renewable power, while nuclear generation and capacity grew more slowly, the report says.
WNISR says global solar generation rose 30% in 2025, while nuclear generation increased 1.1% to 2,703 terawatt-hours. That nuclear increase was driven largely by China, where output rose 7.6%. Outside China, nuclear generation fell 0.2% and remained below its 2006 level. Nuclear accounted for 8.8% of global electricity, the report’s lowest figure in four and a half decades.
The monthly crossover came in stages: wind exceeded nuclear in March 2025, and solar did so in April, WNISR says. From March 2025 through June 2026, one or the other generated more electricity than nuclear in each month. Both technologies separately exceeded nuclear in March, April and May 2026. These monthly comparisons and the annual result describe electricity generated, not installed capacity.
Capacity figures show a sharp difference in expansion rates. WNISR estimates that solar capacity grew by 510 gigawatts to 2,383 GW in 2025, a 27% increase, while wind added a record 159 GW to reach 1,291 GW. Installed nuclear capacity rose by 1.5 GW to 399.5 GW, but operating nuclear capacity fell by 0.5 GW to 368.6 GW, according to the report. The figures distinguish capacity installed from capacity actually operating.
Renewables’ Growing Lead in Power
The finding marks a change in the balance of global electricity generation, but it does not mean nuclear plants have stopped contributing substantial power. Nuclear still produced 2,703 TWh in 2025, according to WNISR. The report’s comparison is significant because solar has now passed nuclear in annual generation while expanding at a much faster rate.
That shift can affect electricity investment and the operation of power grids. Solar and wind output varies with weather and time of day, so their growing share increases the value of storage, transmission and other ways to balance supply. WNISR points to falling battery costs as a potential support for further solar growth. It records 104 GW of grid-scale battery capacity, equal to 257 gigawatt-hours, connected in 2025; more than 78% of cumulative battery storage capacity was installed between 2023 and 2025.
The comparison also puts nuclear construction timelines and delivery under scrutiny. WNISR says none of the 16 reactors connected to the grid from 2023 to 2025 was completed on schedule, and their average construction period was 10.9 years. Those findings provide a measure of the pace of new supply, though they do not by themselves establish which technology is preferable for every grid or country.
As an affiliate, we earn on qualifying purchases.
Capacity Growth and Nuclear Build Times
The report describes nuclear growth as slow and concentrated largely in China and Russia. As of July 1, 2026, it counted 411 operating reactors in 31 countries, excluding 30 units in long-term outage. It also reported 73 reactors under construction, the highest number since 1987, with 37 in China. Nine out of 10 projects under construction were in Asia or Eastern Europe.
That construction pipeline has not yet translated into rapid additions to operating power, the report says. Four reactors began supplying electricity in 2025, while seven closed, producing a negative annual reactor balance for the first time since 2021. Of 13 reactors scheduled to start operating that year, only four did so. WNISR also says nine of the 12 construction starts in 2025 were in China, two in Russia and one in South Korea.
The solar estimate in WNISR is conservative compared with figures cited from the IEA Photovoltaic Power Systems Programme. Those data put 2025 global photovoltaic additions at about 690 GW, roughly 180 GW above the WNISR figure. The difference concerns added capacity, not the report’s annual generation comparison. If the higher additions estimate is used, solar’s capacity growth appears larger still, but the sources use different estimates.
“The reality of the nuclear industry on the ground is quite sobering for those who expected to find a booming sector.”
— Mycle Schneider, WNISR overseer, speaking to pv magazine
Estimates and Comparisons Still Matter
The report’s figures are estimates, and the solar capacity total differs from a more recent figure cited from IEA PVPS. The supplied account does not detail the methods behind each estimate, so the precise size of the difference and its effect on comparisons cannot be independently resolved here. The report’s key claim is about electricity generation in 2025, while the higher IEA PVPS figure concerns new capacity added during that year.
Monthly data in the report extend through June 2026, but the supplied material does not give monthly totals or explain how the figures were compiled. It also does not establish whether the reported trend will continue in every month or year. Battery deployment may help accommodate variable renewable generation, but the report’s account does not quantify how much storage is needed or how its costs and grid effects will develop.
The figures also do not settle questions about reliability, costs, emissions over the full life cycle or the role each energy source should play in individual power systems. WNISR compares generation and capacity trends; broader assessments would require evidence beyond these totals.
Tracking Generation and New Projects
The next useful measure will be whether solar and wind continue to exceed nuclear output in monthly and annual generation data after June 2026. Future reporting can also test whether additions match the report’s projections and how battery deployment develops as grids absorb more variable renewable power.
For nuclear, attention will turn to whether the reactors under construction begin operating on schedule and whether planned projects translate into additional operating capacity. WNISR’s figures show a sizeable construction pipeline but also long timelines and missed expected start dates. The supplied report summary does not give a specific next publication date or a forecast for when projects will come online.
Key Questions
Did solar surpass nuclear in annual or monthly generation?
Both, according to WNISR 2026. Solar exceeded nuclear in annual global electricity generation in 2025. The report says solar also outgenerated nuclear in April 2025 and in every month from March 2025 through June 2026 when either solar or wind individually exceeded nuclear.
How much electricity did nuclear generate in 2025?
WNISR reports 2,703 terawatt-hours of nuclear generation in 2025, up 1.1% year on year. The increase was largely driven by China; nuclear output outside China fell 0.2%.
Does this mean solar has more installed capacity than nuclear?
The headline finding is about electricity generated, not a direct comparison of operating capacity. WNISR reports 2,383 GW of solar capacity and 368.6 GW of operating nuclear capacity, but capacity and annual generation are different measures.
Why do solar capacity estimates differ?
WNISR uses a relatively conservative estimate for 2025 solar additions. The report account cites IEA PVPS data estimating about 690 GW of photovoltaic additions, roughly 180 GW higher. The sources’ estimation methods are not detailed in the supplied material.
What could affect the trend from here?
Future solar and wind additions, electricity demand, grid capacity and battery storage deployment could all affect generation comparisons. Nuclear construction schedules and reactor closures will also shape future output. The report does not establish how these factors will change after its latest monthly data, which run through June 2026.
Source: hn
Fall Picks
fall essentials
As an affiliate, we earn on qualifying purchases.
