The headline from the French energy regulator painted a grim picture: “Unprecedented strain.” As thermometers across the Hexagon hit 42.6°C, the country’s nuclear-dependent power system crumpled. River levels dropped, cooling systems faltered, and reactors were forced offline. By mid-afternoon, rolling blackouts had plunged Parisian suburbs into darkness. Meanwhile, cross the Channel, the tea stayed hot and the lights stayed on.
Britain’s National Grid ESO, the public body responsible for balancing supply and demand, was preparing for this. For weeks, engineers had been stress-testing contingency plans. They had secured emergency gas supplies, fired up coal plants held in reserve, and negotiated flexible demand agreements with major industrial users. When the heatwave hit, the grid barely broke a sweat.
“We have a more diverse mix: gas, renewables, interconnectors, and a bit of coal in reserve,” explained Danni Hewson, energy analyst. “France put all its eggs in the nuclear basket. When the heat cooks the chicken, you’ve got nothing.” The contrast could not be starker. In the UK, homes hummed with air conditioning. In Normandy, families sat in the dark.
But this resilience comes with a price. The cost of keeping the lights on has been loaded onto household bills. Energy price cap rises have sent fuel poverty rates soaring. In the North East, one in five households now spends more than 10% of income on energy. The Labour MP for Sunderland told me: “We’re paying for a secure grid, but for many it’s choosing between eating and cooling.”
And the heatwave is not a one-off. Climate scientists warn that these events will become more frequent and intense. Britain’s grid, while robust today, faces long-term strain. The UK’s wind farms, vital in winter, run less efficiently in heat. Gas plants, while flexible, drive up carbon emissions. And the coal that saved us last week is being phased out by September 2024.
The question now is not just whether we can keep the lights on, but who pays the bill. The government has promised to “build back greener” with wind and solar. But until the storage technology catches up, households may have to accept that power security comes with a cost that hits the kitchen table hardest.
For now, though, Britain can count itself lucky. While France’s grid fails, ours holds. But the north–south divide in energy resilience is a reminder: a secure grid is not the same as a fair one.
