Britain's energy system is bracing for a potential power crunch as temperatures soar towards 34C on Thursday, sparking a warning from grid operator Neso to seek extra supplies. The National Energy System Operator (Neso) issued an urgent request overnight for additional electricity to meet the increased demand from households using fans and air conditioning units to combat the heat.
The move follows a similar appeal by Neso during last month's heatwave, when temperatures reached a provisional record high of 37.7C in Norfolk. Although Thursday's forecast is not expected to match those extreme levels, the prolonged nature of this week's hot spell – potentially lasting over 10 days – is causing concern.
Neso has given power generators an opportunity to make additional generation or flexibility available during the peak period on Thursday evening, when its forecasts indicate tight electricity margins. The operator attributed the strain partly to extreme temperatures across Europe, which have reduced the availability of some generation.
While Neso's 'electricity margin notice' is a standard tool to maintain balance within the system, it can lead to the operator paying higher-than-average prices to gas power plants to guarantee demand. In a statement, Neso reassured the public that there is "no risk to customer electricity supplies," but will continue to monitor conditions and take necessary actions to maintain secure supplies.
The wider European context is also affecting the situation, with French utility company EDF warning that its nuclear reactors are being impacted by the heatwave. The reactors frequently export power to both the UK and Germany, and output could be reduced at up to five of its plants in the coming days due to elevated river water temperatures used for cooling.
The Met Office has issued a yellow warning for extreme heat across large parts of England and Wales from Thursday, with temperatures expected to range from 30-34C in southern areas. In Scotland and Northern Ireland, temperatures will be milder, generally reaching 20-24C, but wind speeds are light, offering little relief from the heat.