Where does the UK's electricity come from? The energy mix explained

Key figures

• 125gof CO2 per kWh was the average carbon intensity in 2024, the lowest year on record and 70% lower than in 2014. In 2020 it was 181g.
• 3,917.7 MWhof electricity was cut or moved away from busy times by the Demand Flexibility Service in winter 2024/25, across 44 events.

The electricity mix, year by year

Gas was Britain's biggest source of electricity until 2024, when wind overtook it for the first time. In 2022, when gas prices soared, gas still made 38.5% of the country's electricity. By 2025 that was down to 26.8%.

Share of electricity generation in Great Britain. There is no 2021 figure in the table below, so the lines break there. Tap or hover on the chart to see each year.

Share of electricity generation in Great Britain. Zero carbon is as NESO defines it. The biggest source each year is in bold. NESO's 2025 review does not give a zero-carbon share. Other sources, where a full breakdown was published: nuclear made 15.5% in 2022, 14.2% in 2023 and 14% in 2024; solar 4.4% in 2022 and 4.9% in 2023; biomass 5.2% and 5%; imports 5.5% and 10.7%. 2022 and 2023 shares are from NESO's monthly electricity statistics as reported by edie and Current±. 2024 shares other than wind and coal are from RenewableUK's summary of NESO statistics.

Renewables (wind, solar, hydro and biomass) made 44% of electricity in 2025, up from 42% in 2024 and about 3% in 2000. They produced about 127 TWh in 2025, a record, against 43 TWh in 2015. 2019 was the first full year in which zero-carbon sources made more electricity than fossil fuels.

Records

How the records have moved

From NESO's annual reviews. A blank means the review for that year did not give the figure. The 2022 carbon intensity record is for a whole day; the others are for a half hour. The 2026 figures are from NESO's announcement of 24 April 2026 and, for wind, from NESO data reported by STV News on 26 March 2026. The 2026 solar record is NESO's estimate of solar on the local distribution networks, where almost all solar is connected. Checked 8 November 2026.

The end of coal

Coal made 43% of Britain's electricity in 2012. By 2020 it was down to 1.6%, and that spring the grid ran for about 68 days without it, from 10 April to 16 June, the longest run since the first public coal-fired power station opened in 1882. Christmas Day 2020 was the first without coal. The last station closed on 30 September 2024.

The zero-carbon grid by 2025

On 1 April 2019 the system operator, then National Grid ESO, said it would be able to run Great Britain's electricity system with zero carbon by 2025, for short periods at first. Its director, Fintan Slye, said the network would be ready to handle 100% zero carbon by then.

In 2025 the closest it came was 97.7% zero carbon for 30 minutes on 1 April, when about 28 million homes and over 5 million businesses were running on zero-carbon power. NESO's 2025 review does not report a full 100% period.

That record was beaten on 22 April 2026, when the transmission network ran at 98.8% zero carbon between 3:30pm and 4pm. Gas fell to 1.2% of the mix that day.

The Demand Flexibility Service in numbers

The Demand Flexibility Service pays households and businesses to change when they use electricity, usually by using less at busy times such as early evening. It began in November 2022, ahead of a winter for which the system operator had warned that power cuts were possible in its worst case. Taking part is optional each time.

To take part you need a smart meter and a supplier or other provider registered for the scheme. The provider tells you about each event and pays the reward, and rewards vary by provider. In the first winter, NESO guaranteed providers £3 per kWh saved in test events, and estimated a typical household could earn about £100. NESO's Demand Flexibility Service page links to the list of registered providers.

From NESO's results for each winter. The 2022/23 total paid out is from Carbon Brief. A blank means NESO did not give the figure.

In 2022/23 the 3,300 MWh saved was enough to power nearly 10 million homes for an hour. Since 27 November 2024 the service has run all year rather than only in winter. From 14 April 2026, people can also be rewarded for using electricity at times that help balance the grid, such as when there is plenty of renewable electricity.