It could cost $100 million and take years to install the backup generators to prevent another hourslong power loss like the one at Britain’s biggest airport last week.

Heathrow’s chief executive has defended the airport’s response to the power outage and shutdown that sparked global travel chaos, apologizing to stranded passengers and confirming the airport is “operating as normal” Saturday.

In 2024, Heathrow was the busiest airport in Europe by passenger numbers and the fourth busiest worldwide. Nearly 84 million passengers passed through its five terminals during the year. These figures highlight the scale of disruption caused by its recent complete closure after a fire at an electricity substation.

London's Heathrow Airport reopened on Saturday after a power outage at one of the world's busiest airports the previous day caused widespread chaos and cancellations.

"Living near Heathrow is noisy, there are planes every 90 seconds or so, plus the constant hum of traffic, but you get used to it, to the point of no longer noticing," said James Henderson, who has lived next to the airport for more than 20 years. "Today is different, you can hear the birds singing."

London's main airport was shut down after a fire caused a power outage, with passengers advised to avoid Heathrow "until further notice."

Heathow's boss and other top exectives have been called to explain the power outage that shut down Europe's busiest airport for almost a day.

London Heathrow Airport was warned about possible issues with its power supplies a few days before a nearby fire cut electricity to the hub and forced Europe’s busiest airport into an unprecedented day-long blackout.