NESO WARNS OF TIGHT POWER SUPPLIES AS HEATWAVE HITS UK

The National Energy System Operator (Neso) issued a notice overnight requesting additional electricity supplies from power generators to manage demand expected during Thursday evening's peak period. The warning came as extreme temperatures affected Great Britain's grid, with parts of southern England forecast to reach 34C. Neso stated that its forecasts indicated tight electricity margins during Thursday evening, attributing the strain to extreme temperatures across Europe that had reduced the availability of some generation capacity. The operator characterised the electricity margin notice as a routine tool used to balance the system and stated there was no risk to customer electricity supplies.

This represents the third heatwave warning issued by Neso within the year. In late June, the operator had requested additional supplies during a previous heatwave when the UK recorded a provisional temperature of 37.7C at Lingwood in Norfolk, surpassing the June record of 35.6C established in 1976. Current temperatures are expected to remain below that June peak, though forecasts indicate the hot weather would persist for approximately 10 days, extending the period of heightened demand.

Across Europe, power systems faced similar pressures. EDF, the French state-owned utility, warned that the heatwave was straining its nuclear reactors, which export power to the UK and Germany. The company indicated that output could be reduced at up to five nuclear plants in coming days as hot weather affected river water temperatures used for reactor cooling. Neso stated it would continue monitoring conditions and take necessary actions to maintain secure electricity supplies.