National Grid chief says Heathrow had ‘enough power’ despite fire shutdown

National Grid’s chief executive has insisted the electricity transmission network remained capable of feeding enough power to Heathrow throughout the airport’s closure last week, as airlines’ anger over the decision to shut down for nearly 24 hours grew.

In his first comments since the fire on Thursday night, John Pettigrew told the Financial Times that while an “unprecedented” blaze knocked out the North Hyde substation, two others serving Heathrow were working throughout the incident.

“There was no lack of capacity from the substations,” he said. “Each substation individually can provide enough power to Heathrow.”

Heathrow closed for nearly all of Friday following the substation fire, causing disruption that is expected to cost airlines tens of millions of pounds. More than 1,300 flights were cancelled, affecting hundreds of thousands of passengers.

The airport said that, while it is able to run full operations with power from only two substations, it had to “reconfigure” its internal electrical networks to safely make the switch.

Heathrow’s chief executive Thomas Woldbye said over the weekend that the airport also had to safely restart thousands of its systems — from baggage belts to air bridges.

He appeared to shift some blame to the power industry as he told the BBC that Heathrow would assess if it needed “a different level of resilience if we cannot trust that the grid around us is working the way it should”.

But Pettigrew said: “Two substations were always available for the distribution network companies and Heathrow to take power.” He added it was a “question for Heathrow” as to why it took the action it did.

“Losing a substation is a unique event — but there were two others available,” he said. “So that is a level of resilience.”

Late on Sunday a spokesperson for Heathrow said: “As the National Grid’s chief executive, John Pettigrew, noted, he has never seen a transformer failure like this in his 30 years in the industry. His view confirms that this was an unprecedented incident and that it would not have been possible for Heathrow to operate uninterrupted.”

National Grid owns and operates Britain’s high voltage transmission network, including the substations around Heathrow, where electricity is fed into lower voltage distribution networks and then on to homes and business. SSEN owns the distribution network in the area.

As they began to recover their operations over the weekend, airlines began to question the length of the shutdown, and whether some terminals could have reopened sooner.

One senior executive said airlines had been “pushing and pushing” Heathrow to reopen.

“It isn’t clear why Heathrow made the decision so early on to close the airport for the entire day . . . It is clear that flights into Terminal 5 could have been enabled early Friday afternoon,” they said.

Another senior executive said that “many” airlines had expected the airport to reopen more quickly, although they conceded its management had faced “difficult” decisions.

A third agreed there were questions over whether all the terminals should have closed for so long.

On Sunday night, the spokesperson for Heathrow said: “In line with our airline partners, our objective was to reopen as soon as safely and practically possible after the fire . . . over the weekend, we were able to focus on operating a full schedule of over 2,500 flights.”

Woldbye said Heathrow reopened as quickly as safely possible, and that and the airport had faced a “major” and “unprecedented” event.

Ministers have ordered an investigation into the incident, and on Sunday chancellor Rachel Reeves said the disruption underscored the need for new airport capacity in London, including a third runway at Heathrow.

The shutdown is expected to cost the airline industry about £60mn to £70mn, according to Andrew Light, a consultant and former senior executive at British Airways owner IAG.

Airlines do not have to pay direct compensation to customers, but must cover hotel bills and other disruption costs. Heathrow has said it is not liable for the airlines’ costs.

Nigel Wicking, chief executive of Heathrow AOC, which represents airlines which use the airport, said: “We already pay enough for the services at Heathrow, we cannot also be paying out where there is lack of resilience and failure of this nature, whether it is Heathrow or their suppliers.”

Pettigrew said the fire at the North Hyde substation — which firefighters have said set ablaze 25,000 litres of cooling oil — was so ferocious it damaged all three transformers on the site, including one which is there for backup and further away from the other two.

He added that the cause of the fire was not yet known as it is still too hot for full forensic work, with third-party involvement still not ruled out. Counterterrorism police are investigating, but have said there were no signs of foul play.

“I can’t remember a transformer failing like this in my 30+ years in industry,” Pettigrew said.

Asked why the site, built in the 1960s, was designed in a way that it was possible for all three transformers to be knocked out by one fire, he said: “You have to build substations in the space available, and obviously you do all you can to mitigate the risks.

“But that is something that clearly I think an investigation will look into a bit further.”

The fire at the substation comes at a time of heightened concern about the risk of damage to the UK’s critical national infrastructure given Russia’s war against Ukraine.

The FT reported on Friday that infrastructure owners were urged in November to be extra vigilant due credible threats coming from Russia.

Asked how concerned he was about the threat from Russia, Pettigrew said: “We always focus on the security of our assets. And I’m not going to go into the details of that.”

There is also heightened scrutiny over electricity networks generally given the shift away from fossil fuels, which involves relying more heavily on equipment run on electricity from wind and solar farms.

“This year alone, we’re investing £10bn in the network, added Pettigrew. “And over the next five years on the transmission system we’ve just submitted a £35bn plan.

“So I am absolutely assured and sure that we are investing in the network for resilience for safety.”