The United Kingdom’s National Energy System Operator (NESO) reported two unexpected frequency fluctuations on Sunday, one day before the massive blackout that affected Spain and Portugal.
According to NESO, the first incident occurred at 2:00 AM with a power outage at the Keadby 2 natural gas power station in Lincolnshire, located in northeastern England. The second was described as an “unexplained failure” in the Viking Link interconnector, a major infrastructure project connecting the UK and Denmark.
Later that same day, around 6:00 PM, NESO detected a third frequency anomaly across the grid serving England, Scotland, and Wales. Notably, Northern Ireland was unaffected, as it operates under a separate grid system.
NESO told Spanish news agency EFE that both disconnected assets were successfully restored on Sunday afternoon, and no power outages or supply losses were reported as a result. “As a prudent system operator, we review all generator disconnections as a routine practice,” NESO said. “We are still analyzing the operational events of the weekend.”
Are the Events Connected to the Iberian Blackout?
UK authorities are now reviewing whether these anomalies are in any way related to the blackout that hit the Iberian Peninsula just 24 hours later. However, NESO emphasized that “it is highly unlikely these events are connected” to the power disruption on the European continent.
As a mostly island-based grid, Great Britain operates under different conditions than continental Europe. NESO noted that, in some cases, the British grid is isolated from broader disruptions affecting the European interconnected electricity system.
Still, the UK grid operator is collaborating with European counterparts to understand the root cause of Monday’s blackout and to offer technical support. “The Great Britain electricity network was not affected by the incident in the European electricity system,” NESO added. “We are working closely with our colleagues across Europe to investigate and assist.”