The interim report into the Heathrow power outage back in March this year has been released today. It makes very uncomfortable reading for a number of parties, not least National Grid & Heathrow Airport itself. Basically, an issue was found with a transformer bushing (a hairline crack, quite common) back in 2018 but nothing was done about it. This allowed the ingress of moisture into the transformer oil, degrading it's ability to insulate over the years. It was due for a routine maintenance in 2022 (when it should have been fixed) but this also got cancelled. It went 'bang' quite spectacularly in March 2025... This is endemic in the electricity industry and goes directly back to privatisation in 1990. This is not a rant about the politics of the situation, but a simple statement of facts, this event highlights the lack of investment in infrastructure. This is common across the whole industry and not just limited to National Grid. Having worked in the industry for 43 years I have a lot more insight than most. 100+ year old cables? Yup, 80+ year old poles? Yup.
The lack of investment is genuinely worrying and causes numerous power outages across the country with the enevitable vast financial losses every year. Under the current Ofgem regulations National Grid and the DNO's have to spend 'X' amount (it varies from each operator) on replacement of assets every year. This is not targeted asset replacement, instead it depends on each operator to decide what they spend the money on. This tends to lead to the 'easy' reinforcement scheme's going ahead and the more challenging ones being put on the back burner, rather like what happened at Heathrow. What it needs is for Ofgem to set a lifespan for assets and then oblige the operators to keep to that lifespan - and fine them if they don't keep to schedule. It's not rocket science...
