John Pettigrew, the CEO of the electricity network firm National Grid, has claimed that London-Heathrow Airport (LHR) had access to two additional substations with “enough power” to keep operations running.
In an interview with the Financial Times, the National Grid boss described the fire at a Hayes substation and the subsequent power outage as an “unprecedented” event while seemingly suggesting that Heathrow had other options available for power.
“Two substations were always available for the distribution network companies and Heathrow to take power,” Pettigrew told the Financial Times. “There was no lack of capacity from the substations. Each substation individually can provide enough power to Heathrow.”
Pettigrew added: “Losing a substation is a unique event but there were two others available. So that is a level of resilience.”
Heathrow was closed for 16 hours leading to disruption for thousands of passengers around the world following the fire at a nearby substation which cut power to the airport.
Responding to Pettigrew’s comments, Heathrow Airport said that “his view confirms that this was an unprecedented incident and that it would not have been possible for Heathrow to operate uninterrupted.”
“Hundreds of critical systems across the airport were required to be safely powered down and then safely and systematically rebooted. Given Heathrow’s size and operational complexity, safely restarting operations after a disruption of this magnitude was a significant challenge,” a statement from the airport said.
On March 24, 2025, Transport Secretary Heidi Alexander appeared to back bosses at Heathrow when she told Sky News that the decision to stop flights was taken because the airport needed to restart systems after moving to a different power source.
Referring to a conversation with the Heathrow CEO Thomas Woldbye, Alexander said: “He told me that whilst there are multiple power supplies into the airport, the fire had created a very significant problem with respect to Terminals two and four specifically and that there had to be some reconfiguration of power supplies into the airport. That meant all the systems had to be turned off and all the systems had to be restarted again in a safe way.”
London Fire Brigade has said the fire “involved a transformer comprising 25,000 [liters] of its cooling oil fully alight”.
“This created a major hazard owing to the still live high voltage equipment and the nature of an oil fueled fire,” said London Fire Brigade Deputy Commissioner Jonathan Smith.
Pettigrew told the Financial Times that the fire damaged all three transformers at the Hayes substation, including one that is positioned away from the two others for backup.
On March 22, 2025, Woldbye was quizzed whether he should remain in his role as criticism surrounding the airport’s inability to carry on operating when faced with the power outage.
Speaking on BBC Radio 4’s Today program, Woldbye was asked if he thinks he should still be in the job and responded by saying, “no comments to that.”
On March 24, 2024, Heathrow said it was operating a full schedule today, with over 1,300 flights planned.
“Our ongoing priority remains serving our passengers and getting them safely and quickly away on their journeys,” the airport wrote on social media.