The hot weather hitting Europe this week will reduce power output from France's nuclear reactor fleet, potentially leading to higher electricity prices at a time when the continent is experiencing its worst energy squeeze in decades.
High temperatures in the Garonne river mean production at the Golfech nuclear plant in the south of the country could be limited from Thursday, EDF said in a filing to grid operator RTE. Temperatures in France and Iberia will be well above average for the next five days and even hotter next week, according to forecaster Maxar.
The cuts are another blow to EDF, whose 56 reactors are vital to Europe's electricity supply because maintenance and inspections are operating at about half capacity. The company estimates that production this year will be the lowest in more than 30 years, meaning neighboring countries may have to seek other resources to keep the lights on.
EDF expects to cut nuclear power production during the summer because of low river levels
The heat wave will increase cooling needs for millions of homes, offices and factories. That has boosted demand for power and threatens to strain the system even more at a time when many plants are already closed for annual summer maintenance.
Sabrina Kernbichler, power analyst at S&P Global Commodity Insights, said: "The current above-average temperatures are likely to increase daytime trading prices in Western Europe this week. Low hydropower stocks and limited rainfall across Europe, particularly in Italy and Iberia, could push up long-term electricity prices.
French electricity prices for next month rose 4.2% on Tuesday to 437.50 euros per megawatt-hour, near an all-time high in August, according to data.
To make matters worse, Germany, Europe's biggest producer of wind turbine electricity, hardly blows. By turning to green energy, the region has benefited from cheap prices when the wind is blowing, but when it is not, old-fashioned factories burning coal and natural gas become more important. On Tuesday morning, wind output was below 3 gigawatts, compared with nearly 50 gigawatts recorded in February.
France's high temperatures, lack of wind power and low nuclear production have pushed already elevated prices even higher. French electricity prices jumped on Tuesday to their highest since April 3, trading at €432.43 per megawatt hour at the EPEX Spot SE auction.
Temperatures in Paris will hit 35 degrees Celsius (95 degrees Fahrenheit) on Wednesday and rise to 38 degrees Celsius next week, according to Maxar. Madrid will reach a scorching 41.5 degrees Celsius on Thursday.
Under French rules, EDF must reduce or stop nuclear power output when river temperatures reach a certain threshold to ensure that water used to cool the plant does not harm the environment when it is released back into waterways. The company warned earlier this month that production cuts were coming.