UK grid operator issues rare summer power supply warning amid heatwave
Britain's National Energy System Operator (Neso) has issued a rare summer electricity margin notice, asking power plants for extra capacity as extreme heat strains the grid.
Great Britain's grid operator issued a rare summer power supply warning for Wednesday evening as the heatwave intensifies, putting pressure on the energy system. The National Energy System Operator (Neso) released an electricity margin notice late on Tuesday, calling on power plant owners to provide any extra electricity as the buffer between supply and expected demand narrows.
A Neso spokesperson attributed the warning to extremely high temperatures affecting both Britain and the continent, coupled with low wind speeds. They stressed that the electricity supply was not at risk and the notice did not indicate an imminent blackout.
Neso, which manages energy systems in England, Scotland and Wales, said it needed an additional 1,900 megawatts of generating capacity to maintain normal safety margins. Electricity demand is expected to rise between 7pm and 10pm on Wednesday as people turn on fans and air conditioning to cope with the heat.
Such notices are more common during cold winter spells. European electricity prices have surged in recent days due to the heatwave, which has boosted demand and caused multiple power plant outages.
A high-pressure system has trapped heat across the region, slowing wind speeds and reducing renewable output. In France, high river water temperatures have hampered cooling at some nuclear plants.
Record June temperatures of 38°C are forecast for southeast England on Wednesday, with 39°C on Thursday. Train operators have urged only essential travel, schools have closed in southern England and Wales, and hospital appointments have been cancelled.
Several trade unions have called for workers to walk out on the hottest day. The UK has no legal maximum workplace temperature, though a minimum of 16°C applies in offices.
