The Night France Saved the British Grid

Inside the control-room nightmare of 23 June: the day Britain's grid ran out of margin — and was saved by a phone call

For forty-eight minutes on the evening of Tuesday 23 June — a 33°C midsummer Monday — the frequency of Great Britain's electricity grid sat below 49.8 Hz, the boundary of normal operation. At 17 seconds past eight o'clock it touched 49.657 Hz, its lowest point of the year — though, as I wrote in the immediate aftermath, it stayed clear of the statutory …