Heatwave in Europe Disrupts Nuclear and Hydropower Plants
Photo: MIT Technology Review
Quick answer
Extreme heat in Europe is forcing energy companies to shut down nuclear plants and reduce hydropower output due to overheated rivers and water shortages.
The second unit of the Golfech nuclear power plant in southern France was shut down overnight on June 23 due to a critical rise in the temperature of the Garonne River. The plant uses river water for cooling, but French regulations limit the temperature of discharged water. Forecasts indicated it could reach 28°C, exceeding permissible levels. Operator EDF decided to shut down the unit as a preventive measure.
The issues are not limited to one plant. EDF, which operates all of France’s nuclear plants, has already reduced output at the Nogent-sur-Seine plant and plans similar measures at other facilities. In July 2025, heatwaves cost France over 7 GW of nuclear capacity—equivalent to Ireland’s entire power grid. However, national grid operator RTE assures that current restrictions will not affect supply stability.
Nuclear plants are not the only ones affected by the heat. Hydropower plants are also struggling: droughts and high temperatures have lowered river water levels, reducing output. In the first five months of 2025, hydropower generation in Europe fell by 13% compared to the same period last year. Experts attribute this to climate change, which is increasing the frequency and intensity of extreme weather events.
Common questions
- Why does heat affect nuclear power plant operations?
- Nuclear power plants use river water for cooling reactors. During extreme heat, water temperatures rise, potentially violating regulations on discharging heated water back into water bodies. This forces operators to reduce power or shut down plants.
- How does heat impact hydropower plants?
- Hydropower plants depend on river and reservoir water levels. Droughts and high temperatures reduce water volumes, lowering electricity generation or forcing plant shutdowns.
- Does the shutdown of nuclear plants threaten Europe’s energy supply?
- Currently, no. France’s grid operator RTE states that current restrictions will not disrupt supply. However, risks increase if heatwaves intensify.
Dzen feed: /feed/dzen.xml · RSS: /feed.xml