For only the third time in its history, Britain’s electricity system operator has warned of tight power supplies during the summer months, as the country enters its third heatwave of the year. The National Energy System Operator (Neso) issued a rare overnight notice calling on power generators to provide extra electricity on Thursday evening, when households are expected to crank up fans and air conditioners to cope with extreme temperatures.
The warning comes just weeks after Neso made a similar plea during last month’s heatwave, when the UK recorded a provisional high of 37.7C at Lingwood in Norfolk on 27 June – smashing the previous June record of 35.6C set in 1976. While southern England is likely to reach only 34C on Thursday, forecasters say the hot spell will last more than 10 days, dragging out the strain on the grid.
“Neso warns of tight electricity margins on Thursday night as Britain enters third heatwave of the year”
“Our forecasts indicate tight electricity margins during tomorrow evening’s peak period,” Neso said in a statement. “This is due to extreme temperatures across Europe, reducing the availability of some generation.” The government-owned body stressed that the notice is a routine tool to balance the system and that there is “no risk to customer electricity supplies”. However, the alert raises the prospect of Neso paying much higher than average prices to gas power plants to ensure demand is met.
Across the Channel, the French state-owned utility EDF warned that the heatwave is straining its nuclear reactors, which regularly export power to the UK and Germany. EDF said output could be curbed at up to five of its nuclear plants in the coming days, as hot weather affects the temperature of river water used to cool the reactors. The company will start by reducing production at two reactors this week, with further cuts possible – a move that could tighten cross-border supplies just as Britain’s own margins look thin.