Last reviewed 9 April 2021

Great Britain’s electricity grid was the greenest it has ever been at 1pm on Easter Monday, new data shows.

The carbon intensity of electricity — the measure of CO2 emissions per unit of electricity consumed — dropped to 39gCO2/kWh, the lowest figure in history. According to new data released by the National Grid Electricity System Operator (ESO), the record low levels beat the previous record of 46gCO2kWh set on 24 May last year.

Sunny spells and blustery conditions, coupled with low demand driven by the Easter holiday, meant renewable sources of power dominated the energy mix over the holiday weekend.

Usage data from the ESO shows that at 1pm on Easter Monday, wind power made up 39% of the electricity mix, solar power 21%, and nuclear 16% — meaning zero carbon power sources made up almost 80% of the nation’s power.

The last 18 months was record-breaking for renewable power sources. Solar power set record levels in May last year with its highest ever level of generation (9.7GW) and its highest share in the energy mix (34%) — providing a third of Britain’s electricity supplies on several occasions.

The record for the highest ever level of wind generation was broken on 13 February 2021 (17.5GW), while 26 August last year saw wind contributing its highest ever share to the electricity mix (59.9%).

Fintan Slye, Director at ESO, described the latest data as “astonishing” and showed the speed of transformation across the electricity grid. “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,” Slye said.

In response to falling electricity demand during lockdown, the National Grid decided to take some power plants off the network, including the four remaining coal-fired plants, which meant that Christmas 2020 was the first ever coal-free Christmas day. Zero carbon renewables powered over half of our electricity demands over the festive period.