Europe heat wave power plants strain grid as temperatures soar

Europe is grappling with an unprecedented heat wave that is forcing Europe heat wave power plants to curtail output as demand for cooling spikes.

Europe heat wave power plants face river‑temperature limits

On 23 June France recorded a peak of ↓ 44°C, the hottest day since records began in 1947. Warm nights kept river water above safe cooling thresholds, compelling EDF to shut Unit 2 at Golfech after the Garonne River approached ↓ 28°C discharge limits. The plant’s cooling loop, which returns water slightly warmer than intake, violated French regulations, prompting a precautionary shutdown at 23:45 local time.

EDF is also throttling reactors at Nogent‑sur‑Seine and other sites, a strategy that mirrors the Reuters report on the July 2025 heat wave when ↓ 7 GW of nuclear capacity was lost.

“The grid is under pressure, but we have sufficient reserve to meet demand,” said RTE spokesperson Jean‑Paul Harreman.

Hydropower is not immune; dry rivers trimmed European hydro output by 13 % in the first five months of 2025, according to Bloomberg. In the UK, five gas‑fired stations reported combined cuts of about 2.5 GW as cooling towers struggled with the heat.

Analysts warn that rising cooling demand—UK air‑conditioner usage has doubled since 2022—will make such constraints more frequent. The International Energy Agency projects global cooling electricity use to double by 2050.

Utilities can mitigate risk by hardening cooling systems, expanding battery storage, and incentivising demand‑response, notes Simone Tagliapietra of Bruegel. EDF estimates €600 million ($680 million) a year in retrofits over the next 15 years.

Dispatch from: Julian Vance

Senior Global Security Correspondent