The continent is wilting. A heatwave of historic scope has settled over Europe, driving temperatures above 40 degrees Celsius in capitals not built for such extremes. In Paris, Rome and Berlin, authorities have resorted to chalk marks on windows to log vulnerable residents. Health workers trace symbols to signal who has been checked, who needs water, who is unaccounted for. The practice, more commonly associated with disaster zones, is now a feature of European summer.
But the story of the crisis is not uniform. As power grids across the continent buckle under the weight of air conditioning units and refrigeration demand, the United Kingdom has emerged as an outlier. The National Grid, operator of Britain’s electricity system, reported no emergency measures on the hottest days. No controlled blackouts. No public appeals to reduce consumption. The system held.
That outcome is not accidental. Over the past decade, the UK has diversified its power generation capacity in ways that its European neighbours have not. Interconnectors to France, Belgium, Norway and the Netherlands allow the import of electricity when domestic supply is tight. Battery storage capacity has expanded sixfold since 2020. And a strategic reserve of gas-fired plants, kept on standby at significant cost, has provided a buffer against the intermittency of renewables.
By contrast, France’s nuclear fleet has been running at reduced capacity due to maintenance problems. Germany’s solar-heavy grid struggles after sunset, when demand peaks. Italy lacks sufficient cross-border links. The chalk marks on European windows are a visible symptom of deeper structural vulnerabilities.
There is, however, no cause for complacency. The National Grid’s resilience in this heatwave does not mean the UK is fully protected against future shocks. The system’s margins remain thin. A prolonged period of low wind, coupled with a simultaneous outage of critical interconnectors, could still expose weaknesses. The warning from this heatwave is that climate-driven extremes are becoming the new baseline.
For now, the data speaks. Among G7 nations, Britain’s grid has proven the most robust through the current crisis. The chalk on the windows serves as a stark reminder of what happens when infrastructure fails. The UK must ensure that its relative success today becomes a foundation for long-term security, not a fleeting achievement in an overheating world.
