National Grid ESO - summer outlook report 2020 - children with solar panel
Great Britain's monthly electricity stats

Ever wonder how much electricity is generated and used in Great Britain?

Zero carbon sources of generation met almost half (45 per cent) the country’s electricity demand in December. Although this is marginally down on average zero carbon sources for last month (47 per cent), a daily zero carbon mix high of 83 per cent was recorded at 3.30am on December 30.

Average carbon intensity (195 gCO2/kWh) slightly increased on November (182 gCO2/kWh), but the lowest carbon intensity was 43 gCO2/kWh on 30th December at 4am - close to the all-time record low of 39 gCO2/kWh on 5th April 2021.

Wind power provided an average contribution to the mix of 27 per cent, just one per cent less than in November, but high-power readings were still recorded. On 29th December at 5.30pm wind generation hit 17.4GW, while on 30th December at 3am the share of wind in the mix reached as high as 57.2 per cent.

In terms of total demand, 25TWH was supplied by the network – the equivalent of 25 billion washing machine cycles. December usually provides a good opportunity to look back on the year, but year-on-year comparisons are hard to analyse. This is because national lockdowns due to Covid-19 in 2020 resulted in highly unusual circumstances with low demand and high zero carbon generation.

However, average carbon intensity has continued to follow the overall downward trend in recent years with a 65 per cent reduction in this measure in the last eight years. Furthermore, the average carbon intensity for the month of October 2021 was the lowest on record (excluding figures from 2020). 

2021 was also a record-breaking year for wind with the highest level and share of wind generation (17.7GW / 62.1 per cent) recorded on May 21.

The decline that we’ve see in the carbon intensity of the system over almost a decade looks set to continue in the years to come. As the Electricity System Operator, we’re committed to running a decarbonised electricity system by 2035, ensuring it can be powered solely by zero carbon sources, for short periods, by 2025.

For a more comprehensive view of electricity supply and demand over winter, read our 2021/22 Winter Outlook report.

Isabelle Haigh, National Grid ESO



Isabelle Haigh

Head of National Control





What happened in December?

Find out about Great Britain's electricity generation and how much came from sources such as wind, solar and biomass in our monthly snapshot.

Our control room experts continue to balance supply and demand second by second as we move into the autumn months – and you can follow the electricity mix live in our carbon intensity app - available on Google Play Store and The App Store.