Renewables generated 34% of the world's electricity in 2025, more than three times nuclear power's 9% share, according to data published by Our World in Data and drawn from think-tank Ember and the Energy Institute's Statistical Review of World Energy.
Share of the world's electricity generated by fossil fuels, renewables and nuclear power, 1985-2025. Renewables include hydropower, solar, wind and bioenergy. Source: Ember; Energy Institute Statistical Review of World Energy (2026), via Our World in Data (CC BY).
The two sources have followed very different paths since 2000, when they supplied a similar share of global power: renewables a little under 20% and nuclear about 17%, the data show. Rapid growth in solar and wind has lifted renewables since then, while nuclear's share has roughly halved. Fossil fuels still produced 57% of the world's electricity in 2025, down from more than two-thirds in the early 2010s.
Nuclear output has not shrunk. Reactors worldwide generated a record 2,702 TWh in 2025, up 35 TWh on the previous year's record, the World Nuclear Association said in September. But the amount of power from nuclear plants is about the same as two decades ago, while the world now produces far more electricity overall, so its share of the mix has fallen.
Most of last year's nuclear growth came from new reactors in China, which added 37 TWh, with France adding 12 TWh and Japan 9 TWh, while reactor closures in Belgium cut output by 7 TWh, according to Ember's Global Electricity Review 2026. Over the same year renewables generated 10,730 TWh, or 33.8% of the total, edging past coal's 33.0% to become the world's largest source of electricity for the first time.
Solar did most of the work. Solar generation rose by 636 TWh, or 30%, to 2,778 TWh in 2025, Ember said, and solar's share of global power generation reached 8.7%, nearly matching nuclear's 8.8%, according to the Energy Institute.
Nuclear construction is picking up. Eleven reactors started construction in 2025, taking capacity under construction worldwide to 82 GWe, against 423 GWe now operating, the World Nuclear Association said. Reactors ran at an average capacity factor of 83.7% last year.