Factcheck: How nuclear, gas, wind and solar power are affected during heatwaves
Heatwaves are becoming more likely and more intense due to climate change, impacting sources of power generation around the world… The post Factcheck: How nuclear, gas, wind and solar power are affected during heatwaves appeared first on Carbon Brief .
Heatwaves, a consequence of climate change, are becoming more frequent and severe, influencing the world's sources of power generation. In June and July 2026, temperatures in several areas of Europe surpassed 40°C. This prompted nuclear reactors to halt operations, gas plants to experience reduced efficiency, wind speeds to decrease, and electricity networks to falter.
While all types of electricity generation experienced varying degrees of impact from extreme heat, some commentators hastily attribute the issue to "intermittent" wind and solar power, while underestimating the effect on sources like gas or nuclear power.
Extreme heat also escalates electricity demand as individuals activate air conditioning units and refrigerators have to work harder. In France, for instance, daily electricity demand increased by almost 20% during a two-week heatwave in June 2026. This frequently results in higher power prices due to strained generation and increased demand, causing electricity to become more expensive. Carbon Brief, amidst a wave of misleading claims, elucidates how key power sources manage extreme heat in this report.
Nuclear power is extensively documented to be affected by heatwaves, with numerous headlines accompanying record temperatures in nations that rely on this technology. France, for example, generates around 70% of its electricity using nuclear power, making it particularly susceptible to heatwave impacts. During the July 2026 heatwave, three of France's 57 nuclear reactors had to be shut down, resulting in a 9% decrease in power production.
This phenomenon is not unique to France; similar occurrences have been observed across various European countries during heatwaves in 2003, 2006, 2015, 2018, 2019, 2022, and 2025. Low river levels on the Danube have also affected nuclear reactors in Romania, Hungary, and Serbia this summer, while a Swiss nuclear reactor was forced to shut down due to high river temperatures.
Nuclear plants that utilize river water for cooling are the most significantly impacted by heatwaves and droughts. These account for 14% of the global nuclear fleet. Approximately 60 of the world's 440 river-cooled reactors are situated in France, with an additional seven distributed across Europe. Nuclear power plants generate heat through fission, which is then used to produce steam.
This steam turns the blades of a turbine connected to a generator, ultimately creating electricity. The cooling water, after this process, is recycled to be cooled again.
Written by urgent.news from Carbon Brief's reporting — not their text. Machine-written — it may contain errors, so check the original before relying on it.
