Global Report Highlights Nuclear’s Declining Role as Renewables Surge Ahead

Nuclear power’s contribution to decarbonization is facing mounting challenges as aging plants, soaring costs, and stalled projects slow its growth, while wind and solar power continue to expand at record pace, according to a new report from Global Energy Monitor (GEM).

Data from GEM’s Global Nuclear Energy Tracker reveal that nearly 40% of all proposed nuclear capacity worldwide—about 566 gigawatts (GW)—has been cancelled, exceeding the combined total of currently operating (401 GW) and retired (116 GW) nuclear capacity.

Europe has seen the sharpest declines, losing 122 GW of planned nuclear capacity to cancellations, a figure larger than the entire operating fleet of any single country. The region has also retired 68 GW of capacity, with 90% of reactors still in operation now over 35 years old.

In stark contrast, renewable energy deployment is accelerating. GEM’s Global Integrated Power Tracker shows more than 600 GW of wind and utility-scale solar capacity is either in pre-construction or under construction across Europe—14 times greater than the 9.3 GW of new nuclear capacity currently being built. Most new nuclear projects are aimed at replacing retiring units rather than adding fresh capacity.

Renewable projects are also expected to come online much faster, with lead times of one to four years compared to a decade or more for nuclear facilities. This timing gap, the report warns, could undermine global climate targets, as nuclear development risks falling short within the narrow window to limit warming to 1.5–2°C.

“Nuclear power lags behind wind and solar on cost, construction time, and market growth,” said Joe Bernardi, Project Manager of the Global Nuclear Power Tracker at GEM. “Projects like Hinkley Point C in the United Kingdom, which remains years from completion, highlight the prolonged build cycles typical of new reactors. Similar delays in France and Finland reinforce this trend. Meanwhile, wind and solar are expanding rapidly with lower costs and faster delivery timelines.”

The report concludes that while nuclear remains a part of the energy mix, renewables are increasingly emerging as the more viable, scalable, and timely solution to meet decarbonization goals.