France and Germany Power Prices Surge Amid Heatwave Supply Crunch

European spot power prices rose by more than 20% on August 11, 2026, as a fifth summer heatwave constrained nuclear output in France and reduced wind power generation in Germany. According to LSEG data reported by Reuters, French day-ahead power prices climbed 21.8% to €142.5 per megawatt hour, while German contracts increased 22.8% to €138.50 per megawatt hour.

French Nuclear Production Limits Due to Heat

High water temperatures and low river levels are forcing France to curtail its nuclear energy production. EDF data indicates that nuclear output is expected to be limited by 7.3 gigawatts at the midday peak on August 12, 2026, representing approximately 12% of the country’s total nuclear fleet. France relies on nuclear power for about 70% of its energy production, according to Reuters.

Specific reactor statuses include two units expected to be fully offline due to high water temperatures and four units with planned limitations. One additional reactor is expected to remain offline because of low river levels. French environmental regulations restrict the amount of heat plants can discharge into rivers, which necessitates output cuts when water temperatures rise.

Alessandro Armenia, an analyst at Kpler, told Reuters that the heatwave is expected to peak between August 12 and August 15, 2026, and that significant shutdowns could last until the start of the following week.

German Wind Output and Gas Reliance

Germany is facing a simultaneous drop in renewable energy generation. LSEG data shows that German wind output is expected to fall by 8.1 GW to 4.7 GW, which is roughly 60% below the average for this time of year. The still weather associated with heatwaves typically limits wind output, forcing Germany to increase its use of gas turbines to fill the energy gap.

This shift toward gas power comes as costs increase due to ongoing disruptions in the Strait of Hormuz, according to Reuters. Because Germany’s energy mix has increasingly displaced coal and gas with wind and solar, the loss of wind speed creates a direct reliance on more expensive gas-fired generation.

Cross-Border Energy Effects and Demand

The shortfall in French nuclear production affects energy markets beyond French borders. Armenia noted to Reuters that nuclear exports from France are typically cheaper than the coal and gas plants that set prices in neighboring countries, meaning outages in France impact power costs in both Germany and Britain.

Rising temperatures are also driving up electricity demand as consumers increase the use of air conditioners and fans. Meteo-France reported that temperatures are expected to continue rising through August 14 and August 15, 2026, reaching between 35 and 39 degrees Celsius in most regions, before potentially falling over the weekend.

The current heatwaves have contributed to water shortages, wildfires, and deaths across Europe, according to reporting from Reuters.