The French energy supplier EDF has signalled it is likely to reduce output at its nuclear power stations on the Rhône and Garonne rivers as heatwaves push up river temperatures, restricting its ability to use the river water to cool the plants.
The state-owned company, Europe’s biggest producer of nuclear energy, said its power stations on the two rivers were likely to produce less electricity in the coming days, but would maintain a minimum level of output to keep the grid steady, Bloomberg News reported.
More heat is forecast in the coming days, with air temperatures of above 35C. The heatwave has led to lower water levels in the Rhône and Garonne rivers and raised the water temperature.
Under French rules, EDF must reduce or halt nuclear output when river temperatures reach certain thresholds to ensure the water used to cool the plants will not harm the environment when it is released back into the rivers.
EDF estimates that its power output this year will be the lowest in more than three decades, which is also a result of plant shutdowns for maintenance and checks. This means that France, traditionally an energy exporter, is relying on imports from neighbouring countries including the UK.
The power cuts threaten to push energy prices even higher after they were sent spiralling following Russia’s invasion of Ukraine in late February.