Wind gave us 6%.
France turned its nuclear down.
Last week wind supplied just 6.6% of Britain's electricity on one of the hottest days of the year, while France cut nuclear output because the cooling water was too warm. The lights stayed on. They stayed on because of gas, imports and luck, and only two of those are things you can plan around.
🍃 The still, hot day is the hard day
Britain's grid copes brilliantly with a windy day and reasonably well with a cold one. The day it finds hardest is hot and still.
Wind at 6.6% is not a malfunction. It is what happens when a high pressure system sits over the country and the air simply stops moving. It can last a week.
Solar carries the afternoon and then hands over to nothing at all around 8pm, while it is still hot and the country is still drawing hard.
⚛️ The backup had a bad week too
Britain imports power through cables from France and the continent, and French nuclear is usually the thing on the other end.
In a heatwave French reactors have to reduce output, because they are cooled by river water and the rivers get too warm to do the job safely.
So the import cable becomes less reliable at precisely the hour Britain needs it most. Our backup plan and their emergency are the same weather event.
🏠 What is left is us
When wind is absent, solar has set, imports are strained and gas is running hard, the only lever left is demand.
This is not doom. It is the whole reason the grid now pays households to shift when they use power. Millions of small, boring, invisible adjustments add up to more than any peaker plant.
It is the cheapest thing on the list, it is already installed in your house, and it is doing nothing.
The lights stayed on last week, which is the only outcome anyone will remember. They stayed on because gas plants were paid a fortune at short notice and France sent what it could spare. There is a cheaper plan, and it involves your washing machine starting an hour later. Nobody is going to make a documentary about that.
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Written by Hoesna Mahmood, founder of FlexMyPower. Published 13 July 2026.
FlexMyPower pays UK households to shift when they use energy. Any tariff, any supplier, no switching. More articles.
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