National Grid, which runs the transmission network, described the moment as a “huge milestone”. The company sees the solar power generated on the distribution networks – or local roads of the system – as reduced electricity demand.
The sunshine meant that solar power produced six times more electricity than the country’s coal-fired power stations on Saturday.
Continued good weather saw solar power generate significant amounts of power on Sunday and Monday too, when it was providing around 15% of electricity generation. Demand on Sunday afternoon was also lower than on Sunday night.
Duncan Burt, who manages daily operations at National Grid, said: “Demand being lower in the afternoon than overnight really is turning the hard and fast rules of the past upside down. It’s another fascinating sign of the huge changes we are seeing in Britain’s energy scene.”
Electricity demand usually peaks around 4pm to 6pm at this time of year, as people return home from work, with demand lower still at weekends. But the early hours of the morning are usually the quietest for the Berkshire control centre that monitors the grid, so a reversal is dramatic.