UK Electricity Grid Report 2025
In 2025, Great Britain generated 289 TWh of electricity. Gas was the biggest single source at 26.7%. Renewables (wind, solar and hydro) supplied 37.7%, or 44.6% counting biomass, and each unit generated averaged 127gCO₂ per kWh. Carbon intensity rose 2.9 g on 2024, one of the occasional backwards steps in an otherwise falling series.
Automated summaryIn 2025, Great Britain's electricity grid generated 289.23 TWh, with gas remaining the single largest source at 26.7%, followed by wind at 23.8% and nuclear at 11.8%. Renewables accounted for 37.7% of generation, rising to 44.6% when biomass is included, while low carbon sources together reached 56.4%, helping bring average carbon intensity down to 126.9 gCO2/kWh across a year in which coal contributed nothing and the grid ran coal-free for all 8,759 hours. National demand totalled 228.8 TWh, peaking at 45.85 GW in a single half hour, while the average wholesale price stood at £80.92/MWh. Notably, prices fell below zero for 244.5 hours over the course of the year, reflecting periods of abundant low carbon supply.
Renewables share
37.7%
44.6% incl. biomass
Low carbon share
56.4%
renewables + nuclear
Carbon intensity
127 g
per kWh · low 22 g, high 295 g
Generation
289 TWh
incl. estimated embedded wind and solar
Coal share
0%
8,759 coal-free hours
Peak wind output
18.4 GW
highest half-hour average
The 2025 generation mix, fuel by fuel
share of GB generation- Gas26.7% · 77.31 TWh
- Wind23.8% · 68.75 TWh
- Imports15.2% · 43.99 TWh
- Nuclear11.8% · 34.15 TWh
- Biomass6.9% · 19.93 TWh
- Solar6.5% · 18.66 TWh
- Other1.6% · 4.67 TWh
- Hydro1.2% · 3.37 TWh
- Storage0.5% · 1.31 TWh
Wholesale prices in 2025
market index (MID), volume-weighted across APX and N2EXThe average UK wholesale electricity price in 2025 was £80.92 per MWh on the market index (MID) basis. Prices were negative for 244.5 hours across the year. The most expensive half hour came on 8 January 2025 (settlement period 34) at £1352.90 per MWh; the cheapest, £-99.01, came on 6 September 2025.
Average price
£80.92
per MWh, volume-weighted
Highest half hour
£1353
8 January 2025, period 34
Lowest half hour
£-99.01
6 September 2025
Negative price hours
244.5
price below £0/MWh
Electricity demand in 2025
GB initial national demand outturn (INDO/INDOD), ElexonGreat Britain used 228.8 TWh of electricity in 2025. The hungriest day was 10 January 2025 (909.3 GWh); the quietest, 25 May 2025 (395.8 GWh). Demand peaked at 45.85 GW on 9 January 2025 (settlement period 35).
Total demand
228.8 TWh
national demand outturn
Peak half hour
45.85 GW
9 January 2025
Highest day
909.3 GWh
10 January 2025
Quietest day
395.8 GWh
25 May 2025
Electricity supplied, 2009 to 2026
TWh per year, generation basis incl. estimated embedded wind and solar- 2009329 TWh
- 2010335 TWh
- 2011322 TWh
- 2012324 TWh
- 2013322 TWh
- 2014310 TWh
- 2015305 TWh
- 2016303 TWh
- 2017301 TWh
- 2018298 TWh
- 2019292 TWh
- 2020276 TWh
- 2021285 TWh
- 2022290 TWh
- 2023275 TWh
- 2024281 TWh
- 2025289 TWh
- 2026151 TWh
Britain supplies markedly less electricity than it did in 2009, even as the economy has grown: efficiency, LED lighting and offshored industry all pushed demand down while the mix decarbonised.
How 2025 compares
- Versus 2024: renewables +1.3 points, carbon intensity +2.9 g.
- Versus 2009, the first year on record: renewables up 34.3 points (from 3.4%), and each unit of electricity 71.5% cleaner (445 g to 127 g).
- Explore the neighbouring years: 2024 · 2026 or the full year-by-year table.
Cite this report
You are welcome to reuse the figures on this page with a link back. Suggested citation:
Purely Energy, "UK Electricity Grid Report 2025", purelyenergy.co.uk/grid-report/2025. Derived from NESO historic generation mix data.
2025 grid questions, answered
How green was UK electricity in 2025?
In 2025, wind, solar and hydro supplied 37.7% of GB generation (44.6% including biomass), low-carbon sources supplied 56.4%, and the average carbon intensity was 127 gCO2 per kWh.
What was the biggest source of UK electricity in 2025?
Gas was the largest single source in 2025, supplying 26.7% of GB generation. The full fuel-by-fuel breakdown is on this page.
How much coal did the UK burn for electricity in 2025?
None. Coal supplied 0% of GB generation in 2025; Britain's last coal power station, Ratcliffe-on-Soar, closed on 30 September 2024.
What was the average UK wholesale electricity price in 2025?
The average UK wholesale electricity price in 2025 was £80.92 per MWh on the market index (MID) basis, volume-weighted across the year's half-hourly trading.
How many hours were UK power prices negative in 2025?
UK wholesale power prices (market index basis) were negative for 244.5 hours in 2025.
How much electricity did Great Britain use in 2025?
Great Britain used 228.8 TWh of electricity in 2025, on the national demand outturn basis (Elexon INDOD).
What was GB peak electricity demand in 2025?
GB electricity demand peaked at 45.85 GW in 2025, on 9 January 2025 (settlement period 35), on the national demand outturn basis.
Use the data
Every figure on this page, as a CSV you can drop into a spreadsheet.
Basis: NESO historic generation mix (GB transmission generation plus estimated embedded wind and solar), aggregated by calendar year, energy-weighted. Renewables is NESO's wind + solar + hydro measure; the biomass-inclusive share is shown alongside. See the live version of this data on our real-time grid map and today's prices on wholesale market data.
Data comes from the Elexon Insights Solution (BMRS), the NESO Data Portal and the Carbon Intensity API, a project by the National Energy System Operator and the University of Oxford Department of Computer Science. Contains BMRS data © Elexon Limited copyright and database right 2026.
Energy decisions for the grid of 2026
The mix above sets the shape of wholesale prices. We turn it into procurement strategy for businesses across the UK, from fixed contracts to flexible purchasing.
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