The Energy Transitions Commission — a body drawing together dozens of energy specialists from around the world, including representatives of the nuclear industry — has put forward the possibility that installed nuclear capacity could roughly double over the next three decades, while projecting that the technology will nevertheless account for a relatively modest portion of the broader shift away from fossil fuels.

According to the document — titled "The Role of Nuclear in the Energy Transition: Complementary but Limited" — viable deployment of nuclear power is projected to remain confined to a handful of nations, a picture the authors assess as unlikely to shift substantially even as demand from artificial intelligence development and power-intensive data centres draws fresh attention to the technology.

The report found that nations endowed with plentiful wind and solar capacity — Australia among them — would face higher costs and longer timelines by orienting their electricity systems around nuclear power, whereas renewables paired with battery storage would offer the quickest and most affordable path to scaling supply in those markets. The document further noted that committing capital to nuclear projects a decade before they come online concentrates scarce resources in a small number of centralised facilities during a period when grid conditions are liable to shift substantially, delivering no net system-cost advantage while increasing dependence on overseas supply chains in ways that the authors said would undermine energy security.

The Energy Transitions Commission report observes that small modular reactors remain one to two decades away from broad commercial deployment, with early US cost projections landing between approximately US$140 and US$270 per MWh — a range that sits above the US$40 to US$190 per MWh associated with large reactors — even as investment and political attention directed at the technology has grown alongside rising AI-driven electricity demand.

Construction costs for comparable reactor designs run four to nine times higher in the United States and Europe than in China and South Korea, with financing arrangements identified in the report as a principal driver of that gap. The same report flags that leaning heavily on nuclear power could leave energy systems exposed to supply chain vulnerabilities.

According to the report, uranium enrichment capacity is held to the extent of 40% by a single country as of 2025, while the manufacture of key nuclear equipment remains spread across no more than six nations — a concentration pattern that the document identifies as a more pressing vulnerability for nuclear supply chains than either safety protocols or the handling of radioactive waste.

A tripling of the world's nuclear generating capacity — from its current level to around 1,500 gigawatts by mid-century — would be required to meet the targets set out under a recent international agreement, the report's findings indicate. Achieving that scale would demand roughly 500 GW worth of extended nuclear operations alongside the addition of approximately 1,000 GW in newly built capacity — a combined construction effort running at about six times the pace recorded in recent years.

The report's authors note that even a nuclear expansion at that scale would account for less than 10% of the investment projected for renewables, grids, and storage — estimated at $2,200 billion annually — while the $200 billion per year directed at new nuclear construction would not reduce the pace at which wind and solar capacity, at around 1,500 GW per year, would still need to be added. Nuclear technology is nonetheless identified in the report as a reasonable path for countries with constrained renewable resources or substantial existing investment in the sector.

The report states that where land availability tightens and conditions for renewable generation prove limited, atomic power tends to deliver the most measurable contribution to an electricity grid.

Forecasts cited in the document place nuclear generation costs in China, South Korea, and India beneath the US$50-per-MWh threshold by 2035, while the same modelling puts France, the United Kingdom, and the United States well above that level — each unlikely to fall below roughly US$125 per MWh. Achieving cost parity between a grid drawing a fifth of its power from nuclear stations and one sourced entirely from renewables would require nuclear build costs in the UK to drop by two-fifths from current levels.

The document's treatment of baseload draws on findings that both the output patterns of renewable sources and the shape of typical demand shift across time, meaning neither is a fixed baseline quantity — nor, the authors contend, does either need to be treated as one. Those who advocate for nuclear energy contend that power grids will require a substantial proportion of always-on generation capacity — nuclear being one example — to maintain reliable supply during periods when output from solar and wind installations falls short.

According to the report, a portfolio of solar generation, wind power, grid-scale storage, and demand-side flexibility has grown capable of covering what was once considered firm baseload territory, leaving assets built around continuous high-utilisation operation — nuclear among them — with a narrower part to play. The document further notes that when solar, wind, hydro, geothermal, batteries, and long-duration storage collectively fall short of covering demand in future clean-power grids, assets with lower upfront capital costs — peaking gas, biomethane, and hydrogen among them — are positioned to fill that residual gap.