Alongside the disruption to the airport, the fire also caused nearly 70,000 residents and businesses to lose power.
Last Friday (21 March), a massive fire at a substation in Hayes caused a significant power outage at the UK’s Heathrow Airport, forcing it to shut down for around 15 hours. The incident grounded more than 1,300 flights and disrupted the travel plans of nearly 300,000 passengers.
While emergency services were able to control the fire, the incident cost the UK economy nearly £5m in lost tourism revenue in just a single day. More importantly however, the incident lead several experts to question the resilience of the country’s grid.
Flights resumed operating the next day, with Heathrow reporting more than 250,000 passengers using the airport. And two days later, the facility returned to normal business, although airlines seem to be infuriated at the loss to their business.
In an interview to the BBC, Heathrow’s chief executive Thomas Woldbye said that “the situation was not created at Heathrow Airport, it was created outside the airport and we had to deal with the consequences”.
There are two other substations with enough capacity to supply the airport, but switching them takes time, explained Woldbye.
What do experts think?
“A substation is where different power lines link together, like a junction on a motorway network,” explains Dr Paul Cuffe, an assistant professor at the School of Electrical and Electronic Engineering at University College Dublin.
“An airport like Heathrow requires a lot of electricity to operate – equivalent to a large town.”
According to videos taken at the scene, it appears that a transformer fire at the North Hyde 275 kV substation caused the power outage. The substation supplies electricity to the airport as well as to tens of thousands of homes and businesses nearby – 67,000 of whom lost power as a result of the incident.
“The exact reasons for such a big impact are unclear at this point, but we do know that the North Hyde substation is in a highly-constrained area of the UK electricity grid,” says Dr Barry Hayes, an associate professor in electrical power systems at University College Cork.
According to a recent draft consultation document by the Scottish and Southern Electricity Networks, there has been a “steep increase in the number of new electricity connection requests across west London, driven by new housing developments, commercial investment and data centres”.
Cuffe says one could argue that a critical piece of national infrastructure like Heathrow deserves its own special grid connection arrangements to secure its supply of electricity further.
“It is ultimately a political and economic question to determine the right level of capital investment into grid infrastructure to avoid the problems that outages like this cause.”
The incident, understood to be accidental, has led the UK’s energy secretary Ed Miliband to order the National Energy System Operator (NESO) to open an investigation.
“I have today commissioned the NESO to carry out an investigation into this specific incident and to understand any wider lessons to be learned on energy resilience for critical national infrastructure, both now and in the future,” Miliband said in a statement on X.
The investigation is expected to report initial findings within six weeks.
“We are determined to properly understand what happened and what lessons need to be learned,” Miliband said.
The airport has also opened its own inquiry into its response to the incident, which will be led by Ruth Kelly, a former UK transport secretary and member of the airport’s board.
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