Europe's Heatwave Threatens Energy Supply Chain as Power Plants Shut Down

Record-breaking heatwaves are disrupting power generation across Europe, placing a strain on the energy supply chain. As countries including France experience unprecedented high temperatures, demand for cooling has surged, while power plant operations have become restricted.

France, in particular, has seen temperatures exceeding 44°C, including June 23rd, the hottest June day recorded since 1947. These extreme temperatures have raised the temperature of river water used by nuclear power plants for cooling, leading to the shutdown or reduced output of some reactors. The Golfech nuclear power plant in southern France shut down its Unit 2 reactor due to rising temperatures in the Garonne River, which it uses for cooling. Operator EDF stated this was a precautionary measure. The plant draws water from the river, uses it to cool equipment, and then discharges it back into the river at a slightly elevated temperature, provided it stays within regulatory limits. The expected water temperature at the time exceeded 28°C, prompting the operator to halt operations. EDF is also reducing the output of other reactors nationwide. At the Nogent-sur-Seine plant, one reactor's output was lowered, and EDF indicated similar measures would likely affect more reactors later in the week. In July 2025, approximately 7 gigawatts (GW) of nuclear power capacity in France were halted due to the heatwave. While French grid operator RTE stated that meeting electricity demand would not be severely impacted, the restrictions on nuclear power plants raise concerns about the stability of the summer electricity supply.

Europe's energy supply is becoming increasingly vulnerable to extreme weather events driven by climate change. Beyond nuclear power, other generation methods are also affected by the extreme heat. Hydropower plants are frequently reducing output or shutting down due to decreased water levels caused by dry weather. From January to May 2025, Europe's hydropower supply decreased by 13% compared to the previous year, attributed to high temperatures and low water levels. In the UK, five gas power plants reduced their output by approximately 2.5 GW due to high temperatures, which stress equipment and reduce the efficiency of cooling towers.

Jean-Paul Harreman, an analyst at energy information provider Montel, explained that the surge in cooling demand is the biggest pressure on Europe's power grids. Air conditioning use is increasing even in countries historically less reliant on cooling technologies; the penetration of air conditioners in UK homes, for instance, has nearly doubled since 2022. According to the International Energy Agency (IEA), global energy consumption for cooling is projected to double by 2050 compared to 2023 levels. This trend, combined with increasingly frequent and intense heatwaves due to climate change, heightens the risk of grid overload.