The weather over Easter weekend led to a surge in renewable energy.
The sunshine and windy weather led to the greenest every day in the UK since National Grid records began in 1935.
Wind turbines and solar farms generated 60% of all electricity and most of the electricity provided was from low-carbon sources.
Fintan Slye from the National Grid has said that the UK’s energy system was transforming “at an astonishing rate”. He said: “This latest record is another example of how the grid continues to transform at an astonishing rate as we move away from fossil fuel generation and harness the growth of renewable power sources.
“It’s an exciting time, and the progress we’re seeing with these records underlines the significant strides we’re taking towards our ambition of being able to operate the system carbon free by 2025.”
Electricity emissions have fallen as shops, offices and other businesses have been largely empty of the past year.
Kate Blagojevic, head of climate at Greenpeace UK, said it was “no time for the UK government to rest on its laurels”.
“Carbon emissions from our homes, farms and roads remain stubbornly high, and only a major government intervention can unblock the impasse,” she said. “As the Glasgow climate summit looms closer, ministers really need to up their game on tackling UK carbon emissions right across the board.”