Energy secretary calls for investigation in power outage near Heathrow

UK Energy Secretary Ed Miliband has ordered an urgent investigation into the power outage at Heathrow Airport caused by a substation fire. The incident, which occurred last Friday, led to the airport's closure and resulted in a large number of flight cancellations.

The Department for Energy Security and Net Zero stated that the investigation, led by the National Energy System Operator (NESO), will provide a comprehensive understanding of the incident and more broadly assess the resilience of the UK's energy system to prevent similar events from happening again. Miliband said: "We are determined to find out exactly what went wrong and to learn the lessons."

The fire at the substation in North Hyde, west London, which supplies power to the airport, led to the cancellation of thousands of flights last Friday, leaving passengers stranded around the world. Energy supplier Scottish and Southern Electricity Networks said the fire caused power outages to more than 16,300 homes, with around 150 people evacuated from surrounding properties. The Metropolitan Police said counter-terrorism officers were "leading enquiries" but were not treating the incident as suspicious.

Miliband said he had commissioned the investigation to "understand what wider lessons need to be learned, now and for the future, about energy resilience of critical national infrastructure." NESO, which operates the UK's electricity grid, is expected to submit initial findings to the energy regulator Ofgem and the government within six weeks. According to flight tracking website flightradar24.com, the airport closure caused disruption to nearly 1,400 flights, with around 120 flights diverted to other airports.

Meanwhile, Heathrow Airport has announced a review of its response to the power outage and its crisis management plans, to be led by former Transport Secretary Ruth Kelly. The airport said it was "open and fully operational" on Saturday morning, but the disruption has raised questions about the resilience of the major transport hub. The airport stated that 50 extra flights had been added to Saturday's schedule to carry an additional 10,000 passengers.

On Saturday, live departure information from Heathrow Airport showed more than 30 flights scheduled to depart from the airport had been cancelled, with more than 15 flights delayed. More than 70 flights scheduled to arrive at the airport were also cancelled, including flights from Doha, Riyadh, Dubai, Manchester and Newcastle.

Farah Rafiq was due to fly from Heathrow with friends to Cambodia on Friday for a friend's wedding, but the mass flight cancellations meant she would miss part of the ceremony. The 24-year-old found an alternative flight from Gatwick Airport that would get her to Cambodia in time for the wedding reception on Sunday afternoon, but she said the new flight cost "twice as much as the original".

In Miami, Charlotte and her family were heading to Heathrow on Thursday night, but their American Airlines flight "was turned around mid-flight," she said. "Since then, I've been stranded in Miami with my one-year-old and three-year-old sons," she told the BBC. She said the family had been "moved from hotel to hotel" but were now hoping to get a flight booked for Sunday.

A spokesperson for American Airlines said the company had been working "around the clock to get customers to and from" Heathrow Airport as quickly and efficiently as possible, adding that it was providing overnight accommodation for passengers affected by the airport closure.

Substations are designed to produce, transform and distribute electricity at suitable voltage levels. Heathrow Airport uses three substations, each with backup power supplies. There are also backup diesel generators and uninterruptible battery power systems that provide enough power to keep safety-critical systems, such as aircraft landing systems, running.

However, when the fire broke out, the substation and its backup power supplies all stopped working. Heathrow Airport's main backup plan was the remaining two substations, but the airport's chief executive, Thomas Woldbye, told the BBC that switching over those substations "takes time." He said the incident "was not caused at Heathrow, it was caused off-site and we had to deal with the consequences of that."

Woldbye welcomed the investigation in a statement on Saturday evening, saying: "We will support all efforts to understand what caused the incident off-site yesterday and the impact it had." Heathrow Airport chairman Lord Paul Deighton said the airport regretted the disruption caused and hoped those affected would "understand that this decision was taken to prioritise the safety of our passengers and colleagues." He added that the airport was "committed to finding any potential lessons to be learned from this unprecedented event as the review is carried out."