Britain has been hit with record June temperatures of 36.4C, with the Met Office issuing a red warning for extreme heat for three consecutive days lasting until Friday.
Noémie Baud, from Montel, an energy consultancy, said Neso appeared to have underestimated the demand increase caused by the heatwave by up to three gigawatts – equivalent to the output of three nuclear power stations.
“Neso appears to have underestimated the amount of demand that we have in the UK,” she says. “The UK now has a lot of shops, industry, offices and businesses, and they all have aircon, so the aircon effect on demand definitely does matter.
“It was underestimated by Neso because we could see that the demand was actually even higher than they forecasted.”
Industry data show that at the peak, between 8pm and 9pm on Wednesday night, Neso was paying sky-high prices of £1,379 per megawatt hour – a massive premium on the usual wholesale power price of around £80 per megawatt hour.
Neso bought up to 2.3 gigawatts of extra capacity, mainly from the Netherlands, to balance the electricity supply system.
