The National Energy System Operator (Neso) has issued a fresh warning about potential power supply strains as Great Britain experiences its third heatwave of the year. The operator issued an overnight notice requesting additional supplies from electricity generators to meet the increased demand from households using fans and air conditioners to cope with the high temperatures.
Record-Breaking Heat and Extended Duration
Last month, the UK recorded a provisional high of 37.7C at Lingwood in Norfolk on 27 June, surpassing the previous June record of 35.6C set in 1976. While temperatures on Thursday are expected to reach 34C in parts of southern England, below last month's peak, the hot weather is forecast to persist for over 10 days, prolonging the strain on the power grid.
Neso's Response and Market Implications
In a statement, Neso said it was “giving participants the opportunity to make any additional generation or flexibility available during the forecast period.” The operator explained: “Our forecasts indicate tight electricity margins during tomorrow [Thursday] evening’s peak period. This is due to extreme temperatures across Europe, reducing the availability of some generation.”
However, Neso emphasized that the “electricity margin notice” is a routine balancing tool and assured there is “no risk to customer electricity supplies.” Despite this, the notice raises the likelihood of Neso paying higher-than-average prices to gas power plants to ensure demand is met.
Impact on French Nuclear Output
Across the Channel, French state-owned utility EDF warned that the heatwave is straining its nuclear reactors, which regularly export power to the UK and Germany. Output could be curbed at up to five nuclear plants in the coming days due to hot river water used for cooling. EDF will start by reducing production and using only two reactors this week, potentially leading to further slowdowns as the heatwave moves across Europe.
Wildfires Across Europe
Western Europe is entering its third heatwave in six weeks, sparking wildfires in France and Spain. According to the European Forest Fire Information System, 35,400 hectares have burned in France, double the average, while 55,128 hectares have been scorched in Spain.
