- An anonymous NESO engineer has alleged that inadequate forecasting and dispatch tools are leaving control room staff with poor visibility and could ultimately contribute to power cuts. NESO rejects the account.
- Ofgem is overseeing two distinct exercises following June’s heat: a regulatory review of system operation and an independent Eversheds Sutherland investigation into whistleblowing allegations.
- The wider issue is whether digital control systems, data governance and operational culture are keeping pace with a grid increasingly dependent on weather-led generation and thousands of flexible assets.
An experienced National Energy System Operator (NESO) engineer has alleged serious weaknesses in the UK’s electricity forecasting and dispatch systems, warning that power cuts are “only a matter of time” unless the problems are addressed.
The unnamed control room engineer told The Times that staff compensate for deficient computer tools with demand calculations written on A4 pads and that forecasts for demand, wind and solar output were inadequate.
The engineer also claimed NESO’s Open Balancing Platform sometimes overlooks lower-cost batteries in favour of more expensive sources and provides operators with poor visibility of the network.
NESO rejected those allegations, saying it uses advanced forecasting systems alongside historic demand curves and weather data, with manual checks supplementing rather than replacing established tools.
It denied that the platform routinely bypasses cheaper assets, saying dispatch decisions also reflect operational requirements and system security. It acknowledged that reducing ‘skip rates’ is an objective and said the platform is already improving them.
The conflicting accounts have not yet been resolved. The latest claims form part of a wider controversy over system operation during extreme heat in the week beginning 22 June, particularly events on 23 June.
Internal preliminary reports previously seen by The Times recorded five safety limit breaches and said system security had been compromised. NESO confirmed the documents were genuine but said they did not represent its final assessment.
Competing inquiries
Ofgem has used licence condition C7.5 to require an in-depth post-event review covering the weather, system conditions, operational decisions, compliance with security standards and lessons for the future.
Separately, law firm Eversheds Sutherland is investigating allegations about operational decision-making and record-keeping, reporting to an independent panel with Ofgem representation. NESO employees can approach the investigators anonymously.
One process must establish how close the physical system came to unacceptable risk and whether rules were followed; the other must test claims about management conduct, records and the handling of internal concerns. Neither has yet reported its findings.
Ofgem has said it remains “very confident” in security of supply, that there was no customer disruption and that at no point was it concerned about meeting demand. It has nevertheless described the allegations as extremely serious, adding that confidence depends on concerns being investigated “rigorously and independently”.
The regulator’s published terms promise to follow the evidence and act if necessary.
Critical infrastructure
The allegations matter beyond one difficult summer day. NESO launched the first stage of the Open Balancing Platform in December 2023 to dispatch batteries and smaller Balancing Mechanism units in bulk. The system is intended eventually to replace legacy balancing and ancillary services platforms.
NESO said at launch that it would increase precision, reduce manual instructions and allow batteries to participate more actively.
That is precisely why problems, if substantiated, would be significant. A system dominated by a few large, visible power stations could rely more heavily on established operator routines. By contrast, a high-renewables system must forecast changing weather, process far more telemetry and select among large numbers of smaller assets quickly.
Software quality, model inputs and the ability of engineers to understand or override automated recommendations become part of security of supply, not merely back-office efficiency.
There are also two different consumer risks. Failure to select an available low-cost battery can increase balancing costs without threatening power supply — but poor situational awareness during a tight period can affect reliability.
The inquiries will need to reconstruct the June event from contemporaneous data, assess assumptions about interconnector support, establish whether limits were breached and determine whether records and escalation worked as intended. Until then, NESO’s assurance and the engineer’s warning remain sharply opposed accounts.
