French Power Strike Cuts 6.5 GW of Output, Affecting 7 Nuclear Reactors
en.Wedoany.com Reported - From the evening of September 14 to the early hours of September 15, a strike in France's electricity and gas sector removed approximately 6.5 GW of generating capacity from the available supply at the time, mainly due to reduced output at seven nuclear reactors operated by Électricité de France (EDF), with several hundred megawatts of gas and hydro capacity also affected. The affected capacity was restored by the morning of September 15, but unions continued their strike action that day.
The action was not launched spontaneously. As early as July 17, four major union organizations in France's electricity and gas sector—FO Énergie et Mines, FNME-CGT, CFE Énergies, and FCE-CFDT—jointly decided to hold industry action and a strike on September 15, with the core dispute centering on the in-kind energy benefit system enjoyed by electricity and gas sector employees, known as the "employee preferential rate." On September 8, the unions once again called on active employees and retirees in the sector to participate in the September 15 action.
Even before the strike, units had already begun reducing load voluntarily. On September 11, some striking workers reduced the output of EDF's Flamanville nuclear power plant ahead of schedule; by the evening of September 14 to the early hours of September 15, the reduction had expanded to seven nuclear reactors and extended to some gas and hydro units. This 6.5 GW decline was a voluntary reduction caused by labor action and must be distinguished from unplanned outages caused by equipment failures.
This labor dispute involves the long-standing "Tarif Agent" system in France's electricity and gas sector. The preferential rate currently covers approximately 140,000 active employees of companies including EDF, Enedis, RTE, GRDF, Engie, and NaTran, while about 160,000 industry retirees also receive related benefits. Unions regard this system as a component of compensation within the national employee status framework of France's electricity and gas sector, and have therefore made maintaining this benefit a direct demand of the current action.
The French Court of Auditors has previously reviewed the costs associated with these energy benefits on multiple occasions. Its public documents show that the so-called employee preferential rate corresponds to electricity and gas supplied by EDF and other companies to industry personnel at prices significantly below regulated retail rates, and involves EDF settling related costs with Enedis and RTE. In 2023, price changes alone increased the cost of the system by approximately €205 million; earlier audit reports also estimated that EDF incurred approximately €295 million in lost revenue in 2017 as a result.
This round of strikes occurred directly at a stage when French nuclear power supply had recovered to relatively high levels. Data published by EDF for the first half of 2026 show that the group's total generation was 262.1 TWh, of which French nuclear output reached 189.9 TWh, an increase of 8 TWh compared with the same period in 2025. About 70% of France's electricity comes from nuclear power, so the simultaneous reduction in output at seven reactors constituted the main portion of the 6.5 GW supply decline.
Several days before the strike, some EDF nuclear units had just resumed supply. Unit 1 of the Paluel nuclear power plant completed its fourth ten-year overhaul and was reconnected to the grid on September 12; the unit is a 1,300 MW-class reactor. Unit 3 was reconnected to the French national grid at 9:12 on September 14. EDF confirmed that day that all four Paluel units were in operation. Unit 2 of the Blayais nuclear power plant was also reconnected to the grid on September 12. These normal maintenance and technical outages are different operational events from the subsequent strike-related output reductions.
As of the morning of September 15, the overnight decline in generating capacity caused by this round of strikes had been restored, and publicly available information did not indicate any large-scale customer power outages in France. The unions' planned action was scheduled to last through September 15, so the actual generating output of EDF's nuclear, hydro, and gas units still depended on the output reductions taken by workers participating in the strike that day.
