A report into the fire that shut down Heathrow Airport for nearly a day has been released, revealing key causes of the shutdown. The National Energy System Operator (NESO) identified moisture as the likely cause of the fire, which occurred at an electricity substation. Here are five key findings from the report.
Moisture entered a “supergrid transformer”, causing a short-circuit and sparking a catastrophic failure that led to two transformers being taken offline and power to the airport being cut.
The issue was first detected seven years ago by National Grid, but signs were ignored or postponed until basic maintenance was deferred in 2022. Multiple attempts were made to schedule maintenance, but none went ahead.
Heathrow Airport knew that a problem with one of its three grid connections would require it to close for up to 12 hours if the other sources of supply failed. However, it did not consider this scenario likely enough to spend billions on upgrading its resilience.
National Grid and local network operator SSEN were unaware of the critical importance of the substation to Heathrow’s operations, raising concerns about better communication between National Grid and energy suppliers.
The report calls for improved communication between Critical National Infrastructure (CNI) operators and their energy suppliers to prevent supply interruptions. Heathrow is now considering legal action against National Grid over what it sees as “clear and repeated failings”.
Source: https://www.bbc.com/news/articles/c2eznzp0w7ko