An anonymous whistleblower has claimed that power cuts in Britain are only "a matter of time" unless bosses at the National Energy System Operator (Neso) address serious flaws in the way the electricity grid is managed. The engineer alleged that control room staff still rely on pen-and-paper calculations to forecast demand and criticised Neso's digital Open Balancing Platform for providing poor network visibility and sometimes failing to use batteries efficiently, wasting consumers' money. The claims matter because they raise questions about the resilience of Britain's energy system amid the shift to renewables, and follow warnings that the grid came close to serious trouble during a heatwave earlier this year.

The whistleblower told The Times they believe an ongoing Ofgem-ordered investigation will conclude the system was secure on 23 June, when leaked documents suggested the network nearly shut down due to a shortfall of wind and solar power, but said this "doesn't tell the full story" and that reliance on European interconnectors is not guaranteed. They further accused senior management of prioritising image over safety and warned a partial blackout is inevitable without action. Neso has firmly rejected the allegations, denying that concerns are ignored, that forecasting relies on paper, or that its balancing platform overlooks cheaper energy sources, while separate whistleblowers and energy consultant Kathryn Porter have previously warned the grid is at its most fragile since privatisation in 1990, partly due to plans to reduce system "inertia" to save £96 million a year.