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<\/div>\nA fire that shut London\u2019s Heathrow airport in March, stranding thousands of people, was caused by the UK power grid\u2019s failure to maintain an electricity substation, an official report said on Wednesday, prompting the energy watchdog to open a probe.<\/p>\n
The closure of Heathrow, Europe\u2019s busiest airport, cost airlines tens of millions of pounds. It also raised questions about the resilience of Britain\u2019s infrastructure.<\/p>\n
Energy minister Ed Miliband called the report \u201cdeeply concerning,\u201d after it concluded that the issue which caused the fire was identified seven years ago but went unaddressed by power grid operator National Grid. Energy regulator Ofgem said it was \u201ca preventable, technical fault.\u201d<\/p>\n
The report follows a review of the March 21 incident by the National Energy System Operator, which manages the electricity network and was separated from National Grid last year.<\/p>\n
As a result of the report, Ofgem launched an enforcement investigation into National Grid Electricity Transmission (NGET), which owns and maintains the high-voltage electricity transmission network in England and Wales.<\/p>\n
Heathrow said via email that it was considering whether it wanted to pursue legal action, and that it expected National Grid to take \u201caccountability for these failings.\u201d Heathrow itself, along with airline companies, could potentially face a hefty compensation bill for the disruption caused to travelers.<\/p>\n
Full Audit<\/strong><\/p>\n The report said a \u201ccatastrophic failure\u201d on one of the transformer\u2019s high-voltage bushings at NGET\u2019s 275 kilovolt substation caused the transformer to catch fire, most likely due to moisture entering the bushing, sparking an electrical fault.<\/p>\n Despite detecting an elevated moisture reading in one of the bushings in 2018, which indicates an imminent fault that requires the component to be replaced, the company did not fix the issue, the report said.<\/p>\n The controls in place were not effective and failed to identify that no action had been taken, including during an opportunity in 2022 when NGET decided to defer basic maintenance, letting the issue go unaddressed, it added.<\/p>\n A National Grid spokesperson said that the company had a comprehensive asset inspection and maintenance program in place and that it had taken further action since the fire.<\/p>\n \u201cThere are important lessons to be learnt about cross-sector resilience and the need for increased coordination,\u201d the spokesperson said.<\/p>\n Ofgem plans to review whether National Grid complied with the relevant legislation and license conditions relating to the development and maintenance of its electricity system close to Heathrow.<\/p>\n The regulator will also commission an independent audit into National Grid assets to review whether the failings were a one-off or systemic, it said.<\/p>\n In an earlier response to the report, Heathrow blamed the incident on a \u201ccombination of outdated regulation, inadequate safety mechanisms, and National Grid\u2019s failure to maintain its infrastructure.\u201d<\/p>\n Its own review found in May that the airport had responded well to the power outage, saying alternative choices would not have materially changed the outcome on the day.<\/p>\n (Reporting by William James, additional reporting by Sam Tobin; editing by Muvija M, Alison Williams and Mark Potter)<\/p>\n Photograph: Fire at the North Hyde electrical substation led to the closure of the Heathrow Airport, in London, on March 21, 2025.(AP Photo\/Kirsty Wigglesworth).<\/em><\/p>\n Related:<\/strong><\/p>\n<\/p><\/div>\n<\/p><\/div>\n Was this article valuable?<\/p>\n<\/p><\/div>\n