Britain’s Ageing Grid Is Catching Fire — Yet Ministers Keep Pouring Money Into Renewables

When a 57-year-old transformer exploded at National Grid’s North Hyde substation near Heathrow earlier this year, it didn’t just plunge the UK’s busiest airport into chaos. It exposed a national crisis that has been ignored for decades: Britain’s power grid is dangerously old, under-maintained, and unfit for the renewable-heavy energy system politicians keep promising.The fire shut down power to Heathrow and stranded an estimated 270,000 passengers, marking one of the most severe infrastructure failures in modern British history.[1] The cause? A transformer built before many of today’s safety standards even existed. Modern rules require blast walls, physical separation and fire containment — none of which North Hyde had. It was built in the late 1960s, and like hundreds of other substations across the country, it has simply been left to age unnoticed until something went catastrophically wrong.Following the Heathrow disaster, Energy Secretary Ed Miliband has now ordered Britain’s three transmission monopolies — National Grid, Scottish Power Transmission and SSE Transmission — to conduct safety audits across all 500 to 600 high-voltage substations.[2] The problem is that these obligations already existed. It took the country’s largest airport grinding to a halt before ministers acted.The truth emerging is stark: the UK has spent the past 15 years investing heavily in new renewable projects while neglecting the very arteries that keep the nation powered.

The Grid Can’t Support What Politicians Keep Bolting OnBritain’s high-voltage network was largely built between the 1950s and 1970s, and many substations show it.[3] These facilities contain equipment designed for a 40-year lifespan — but they’ve been in service for more than half a century. Some sites are so cramped that modern safety upgrades are physically impossible without purchasing additional land.And yet, renewable expansion — solar farms, wind farms, BESS clusters — continues to accelerate at breakneck speed. Each new installation requires grid capacity, new transformers, new circuits, new substations and, very often, expensive reinforcements. But the existing grid can’t even cope with normal operations, let alone the extreme stress created by intermittent, weather-dependent generation.This contradiction, laid bare by the Heathrow fire, leads to a simple conclusion:The UK is building an energy future on top of infrastructure from the past.

The Hidden Cost of Renewables: A Grid We Haven’t Paid ForPoliticians regularly claim renewables are “cheap”. Wind and solar “cost less than fossil fuels”. But this narrative depends on ignoring the most expensive part of the entire system: the national grid required to move the power around.As energy experts point out, the real cost is not generation — it is the massive web of reinforcements needed to connect renewables.[4]Even the inspections following the Heathrow fire will be cheap compared to the upgrades required:replacement of ageing transformersmodern fire-control systemswider site layoutsdigital monitoringnew switching and cooling systemsThese works may cost “hundreds of millions”, according to analysts — and that is for upgrades, not expansions.[5]But the UK is already pursuing one of the largest grid expansions in its history, driven almost entirely by renewable deployment targets. Offshore wind, solar farms, hydrogen-ready infrastructure, and battery clusters all require new substations, new pylons and new super-grid transformers. The total bill is now well above £100–£200 billion through the 2030s.Meanwhile, our actual, physical, on-the-ground substations are burning down.

The Heathrow Fire Is a Warning — But No One Is ListeningThe National Energy System Operator (NESO) found that National Grid was using multiple fragmented processes to assess substation risks, with no single method for understanding cumulative danger.[6] That means the operator responsible for Heathrow’s power supply had no unified view of fire risk, ageing equipment or safety mitigation.This is not just a paperwork issue. It is a structural failure at the heart of the national grid — one that puts millions at risk.Yet instead of addressing the deep engineering problems revealed by the fire, ministers continue to focus almost obsessively on accelerating renewable deployment. The Clean Power 2030 target, the push for new solar mega-farms, the Onshore Wind Taskforce — all proceed without any credible national plan for maintaining, let alone modernising, the critical infrastructure beneath them.The Heathrow fire shows what happens when ideology outruns engineering.

Britain Is Chasing Net Zero While Running a 1970s NetworkWhy does this matter? Because every new solar farm, every new wind cluster and every new BESS site adds further strain to an already vulnerable system. Intermittent power increases voltage swings, requires more switching, and adds stress to transformers already past their designed lifespan.In engineering terms:You cannot electrify everything while running equipment built before colour television existed.But this is exactly what current policy demands.Rather than a long-term grid renewal strategy, Britain has a patchwork of overstretched assets kept alive by maintenance budgets perpetually squeezed in favour of politically attractive renewable subsidies. The Heathrow incident proved what many experts have been warning for years:Britain is one substation failure away from major regional power loss.And with more than 500 substations in similar condition, the next failure is not a question of “if”, but “when”.

The Real Lesson: Fix the Grid First, or the Transition Will CollapseThe Heathrow disaster should have triggered a national rethink. Instead, it has triggered a national audit. Important, yes — but utterly insufficient.The UK cannot electrify transport, heating and industry while operating critical substations designed before modern safety standards existed. Nor can it keep adding intermittent renewable capacity without the hardened grid infrastructure needed to stabilise it.The political class continues to promise “cheap green energy”, but the reality is this:Without a rebuilt, resilient, modernised grid, every penny spent on new renewables is a gamble with national security.Britain cannot continue to chase ideological deployment targets while ignoring the concrete, steel and copper upon which the entire system depends.Heathrow was the warning shot. Whether ministers listen will determine whether the next failure is an inconvenience — or a nationwide crisis.

Shane Oxer — Campaigner for fairer and affordable energy

Footnotes

[1] Telegraph, “Miliband orders review of UK’s ageing power grid after Heathrow fire”, 18 November 2025.

[2] Ibid.

[3] Rahmat Poudineh, Oxford Institute of Energy Studies, quoted in the article.

[4] NESO, “Beyond 2030” and associated Grid Reinforcement Reports (regional blueprints).

[5] Oxford Institute of Energy Studies, quoted in the Telegraph article, 18 November 2025.

[6] NESO July 2025 Review of North Hyde Substation Fire.