Great Britain’s grid operator warns again over power supplies in heatwave

The National Energy System Operator (Neso) issued a notice late Thursday, asking generators to provide as much extra power as possible for Friday evening to meet rising demand as households use air conditioners and fans to cope with the heat.

Neso stated that forecasts showed "tight margins on the electricity system" for Friday evening due to "the impact of extremely high temperatures affecting Great Britain and the continent." The government-owned body emphasized that electricity supply is not at risk, indicating a blackout is not imminent.

This is the second market warning this week. On Tuesday evening, Neso called for backup power ahead of a demand spike on Wednesday evening, when a high-pressure heat dome that has caused Europe's worst heatwave was expected to slow wind speeds, impacting renewable energy supplies.

Neso was forced to pay generators well above normal market prices to ramp up output. It is estimated to have paid about £10 million for a few hours of power on Wednesday evening, mostly to gas plants. Similar high payments are expected for Friday evening.

Several gas power plants in the UK have reduced output due to the heat. In France, a major electricity supplier to the UK, four nuclear plants reported unplanned outages because river water temperatures were too high for cooling reactors.

French state-owned utility EDF announced it would allocate €80 million (£69 million) to equip schools, nurseries, and daycare centers with cooling systems to help them cope with future heatwaves.