The National Grid issued a surprise warning on its capacity for Tuesday night as British households were expected to increase energy consumption during the cold snap.
A 'tight electricity margin' notice was sent out warning of a potential shortage from 7pm.
The National Grid quickly cancelled notice as its contingency plans were activated, but experts said it was a signal of "much tighter days ahead".
The electricity network operator issues such warnings when "there may be less generation available" than operators expect will be needed "to meet national electricity demand".
It comes with temperatures dropping as Britain heads into the winter months, combined with a drop in the amount of wind power typically generated. The pinch point for the grid came as wind power generation fell to a low as 3,958 megawatts at noon on Tuesday – less than half of the 10,000 megawatts produced a day earlier.
Phil Hewitt, director at Enappsys, said: "This is the first tight day of the winter but it is not super tight.
"It is a small appetizer of tightness, there will be much tighter days ahead."