Nuclear power plants worldwide generated more electricity in 2025 than in any previous year on record, the International Energy Agency confirmed in its Electricity 2026 report. Combined with surging wind and solar output, that record helped push low-emissions sources to 42% of global electricity generation last year. The IEA now projects that nuclear and renewables together will supply roughly half of all electricity by 2030, a milestone that, if reached, would mark the first time clean sources matched fossil fuels on the global grid.
Where the nuclear gains came from
Three countries drove most of the increase. China has been commissioning large new reactors faster than any other nation, steadily expanding a fleet that now ranks among the world’s biggest. France, which relies on nuclear for the bulk of its domestic power, bounced back after years of maintenance shutdowns and corrosion inspections that had forced dozens of reactors offline. And Japan continued restarting units idled since the 2011 Fukushima disaster, reclaiming capacity that had sat dormant for more than a decade.
The IEA’s historical generation chart tracks these regional swings and shows how their combined effect lifted global nuclear output past its previous peak. The United States, still the world’s largest nuclear generator by installed capacity, contributed steady baseload production, supported in part by federal production tax credits that have improved the economics of existing plants.
The road from 42% to 50%
Closing an eight-percentage-point gap in five years is ambitious. The IEA’s own analysis lays out four conditions it considers necessary for nuclear to sustain its upward trajectory beyond the current cycle.
First, governments need to maintain or expand policy support with clear, long-term signals about nuclear’s place in their energy mixes. More than 20 countries signed a declaration at COP28 in December 2023 pledging to work toward tripling global nuclear capacity by 2050, but translating that pledge into permitted, financed projects remains a separate challenge.
Second, developers need better access to financing. Nuclear plants carry enormous upfront capital costs, and even projects with competitive lifetime operating expenses can stall if lenders view construction risk as too high. The IEA flags this as an especially acute barrier in emerging economies across South Asia and sub-Saharan Africa, where electricity demand is growing fastest but capital is scarce.
Third, progress on small modular reactors could open new markets and reduce construction risk. No commercial SMR fleet operates at scale anywhere in the world as of mid-2026, and deployment timelines hinge on regulatory approvals that vary widely by country. The IEA treats SMRs as part of the longer-term solution but does not assign them specific generation targets for 2030, implicitly acknowledging that most near-term growth will still come from conventional large reactors and, above all, from renewables.
Fourth, lifetime extensions for aging plants that still meet safety standards could deliver additional low-carbon electricity at relatively low cost. Several countries, including the United States and France, have already moved to extend operating licenses for existing reactors, a faster and cheaper route to maintaining nuclear output than building from scratch.
What the numbers do and don’t tell us
The IEA’s projections are grounded in national energy data submissions from member and partner countries, making them the most comprehensive baseline available. But they are still projections, and several gaps are worth noting.
The agency has not published an exact terawatt-hour figure for 2025 nuclear output in its executive-level documents, so the margin by which last year’s generation surpassed the previous record remains unclear. Regional breakdowns for 2025, particularly how much of the gain came from Chinese new builds versus French recovery versus Japanese restarts, have not yet appeared in top-level reports. More granular data will likely arrive in subsequent releases later this year.
There is also a timing wrinkle. The IEA’s Global Energy Review 2025, covering the 2024 power mix, reported that renewables and nuclear together supplied about two-fifths of global generation that year, with renewables at roughly one-third and nuclear at 9%. The jump from two-fifths in 2024 to 42% in 2025 depends on final audited data that may not be published for months. These figures are rounded estimates rather than precise accounting, which is standard in global energy statistics where national reporting methods differ and late revisions are common.
Rising demand complicates the picture
Even as clean sources grow, so does the amount of electricity the world consumes. The IEA’s Electricity 2026 report highlights surging power demand from data centers, electric vehicles, and industrial electrification. Reaching a 50% low-emissions share requires not just building more clean capacity but building it fast enough to outpace demand growth that shows no sign of slowing.
Coal’s share of global generation is declining, but the IEA describes a gradual erosion rather than a sudden collapse. In regions like Southeast Asia and parts of Eastern Europe, coal remains the cheapest available option for meeting baseload needs, and new coal plants continue to be built. If nuclear financing falls short or reactor projects stall, the gap is most likely to be filled by natural gas or, in some markets, coal, pushing emissions higher than current climate models anticipate.
Emerging economies present the sharpest test. Countries facing rapid population growth and industrialization need enormous amounts of new generation capacity. Whether they can access the international financing required to build nuclear plants, or instead default to fossil fuels, will determine whether the IEA’s global forecast holds or fractures along regional lines.
Where nuclear fits in the race to 2030
The IEA’s baseline scenario now assumes that half the world’s electricity will come from sources that produce little or no carbon dioxide by 2030. That assumption is already shaping how governments set emissions targets, how utilities plan capital spending, and how regulators evaluate grid reliability.
Nuclear’s record year is a concrete data point in that broader shift. After more than a decade of flat or declining output in many high-income countries, the technology is adding to a fast-growing pool of low-emissions electricity alongside wind, solar, and hydropower. But the path from record output to sustained growth runs through uncertain terrain: reactor construction timelines that routinely slip, political environments that can shift with a single election, and capital markets that do not always reward projects with 10-year build schedules and 60-year payoffs.
The 2025 record proves that nuclear can still grow. Whether it grows fast enough to help the world hit that 50% target by 2030 depends on decisions being made right now in finance ministries, regulatory agencies, and boardrooms from Beijing to Brussels to Washington.
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*This article was researched with the help of AI, with human editors creating the final content.
