In November 2025, Britain's electricity averaged 127 gCO₂/kWh, in the low band (70–139 g). That is 8% cleaner than October 2025 (138 g), and 26% cleaner than November 2024 (171 g). Wind made 40.5% of the electricity generated, gas 28.7%, nuclear 11.3% and biomass 9.0%; low-carbon sources together made 62.9%. The cleanest half hour was 33 g at 10:00 on Saturday 1 November, and the dirtiest 260 g at 07:00 on Friday 21 November. The cleanest day was Saturday 1 November (63 g on average); the windiest was Monday 3 November (62.1% wind).
Carbon intensity, day by day
Day by day, as a table
| Day | gCO₂/kWh | Low-carbon | Wind | Solar | Gas | Half hours |
|---|---|---|---|---|---|---|
| Sat 1 Nov | 63 | 81.3% | 59.2% | 3.9% | 11.6% | 48 |
| Sun 2 Nov | 80 | 75.6% | 48.5% | 4.8% | 15.3% | 48 |
| Mon 3 Nov | 65 | 81.1% | 62.1% | 1.9% | 13.4% | 48 |
| Tue 4 Nov | 81 | 75.0% | 53.0% | 1.7% | 15.3% | 48 |
| Wed 5 Nov | 110 | 65.2% | 41.7% | 1.5% | 22.9% | 48 |
| Thu 6 Nov | 204 | 39.0% | 15.0% | 1.7% | 49.3% | 48 |
| Fri 7 Nov | 201 | 40.6% | 18.0% | 1.3% | 49.2% | 48 |
| Sat 8 Nov | 186 | 43.2% | 17.8% | 4.0% | 44.4% | 48 |
| Sun 9 Nov | 145 | 55.8% | 31.6% | 1.9% | 33.3% | 48 |
| Mon 10 Nov | 131 | 59.7% | 38.8% | 1.5% | 28.9% | 48 |
| Tue 11 Nov | 92 | 69.7% | 49.1% | 0.9% | 18.4% | 48 |
| Wed 12 Nov | 102 | 67.8% | 48.6% | 1.3% | 21.2% | 48 |
| Thu 13 Nov | 111 | 66.0% | 44.8% | 2.9% | 24.9% | 48 |
| Fri 14 Nov | 79 | 76.5% | 57.3% | 0.4% | 16.0% | 48 |
| Sat 15 Nov | 102 | 68.4% | 46.3% | 1.1% | 21.7% | 48 |
| Sun 16 Nov | 145 | 55.9% | 31.9% | 1.7% | 33.5% | 48 |
| Mon 17 Nov | 141 | 59.0% | 35.4% | 3.8% | 32.1% | 48 |
| Tue 18 Nov | 181 | 50.8% | 29.0% | 1.8% | 42.6% | 48 |
| Wed 19 Nov | 130 | 65.8% | 46.0% | 1.9% | 29.9% | 48 |
| Thu 20 Nov | 172 | 56.3% | 36.5% | 2.5% | 41.1% | 48 |
| Fri 21 Nov | 212 | 45.6% | 23.4% | 3.4% | 50.4% | 48 |
| Sat 22 Nov | 136 | 60.1% | 37.4% | 0.8% | 29.2% | 48 |
| Sun 23 Nov | 70 | 77.4% | 51.9% | 2.6% | 11.0% | 48 |
| Mon 24 Nov | 143 | 61.4% | 39.9% | 1.1% | 34.0% | 48 |
| Tue 25 Nov | 183 | 49.6% | 26.9% | 2.9% | 44.6% | 48 |
| Wed 26 Nov | 183 | 51.4% | 30.7% | 2.0% | 44.7% | 48 |
| Thu 27 Nov | 87 | 77.4% | 56.7% | 0.7% | 18.6% | 48 |
| Fri 28 Nov | 83 | 77.7% | 56.3% | 2.1% | 17.7% | 48 |
| Sat 29 Nov | 77 | 74.0% | 48.9% | 1.2% | 14.7% | 48 |
| Sun 30 Nov | 122 | 58.7% | 33.5% | 2.4% | 30.9% | 48 |
What powered the grid
Each fuel's average share of the electricity generated in Great Britain in November 2025, with November 2024 beneath it for comparison. Imports count as one source, as NESO counts them.
Hours in each carbon band
- Very low (under 70 g): 138 hours, 19%
- Low (70–139 g): 290 hours, 40%
- Moderate (140–219 g): 260 hours, 36%
- High (220–299 g): 33 hours, 5%
Records in November 2025
- Cleanest half hour
- 33 g 10:00 on Saturday 1 November
- Dirtiest half hour
- 260 g 07:00 on Friday 21 November
- Most wind
- 71.0% 02:30 on Saturday 1 November
- Most solar
- 21.2% 11:00 on Sunday 2 November
- Most low-carbon
- 93.6% 10:30 on Saturday 1 November
- Least gas
- 5.0% 09:00 on Saturday 1 November
- Cleanest day
- 63 g Saturday 1 November
- Dirtiest day
- 212 g Friday 21 November
- Windiest day
- 62.1% wind Monday 3 November
- Sunniest day
- 4.8% solar Sunday 2 November
About these figures
GridMonkey records NESO's carbon intensity and generation mix for Great Britain every half hour: the actual figure where NESO has published one, otherwise its forecast. They are added up by UK calendar day and month. Percentages are shares of the electricity generated, imports included, so the fuels add up to 100%. Low-carbon means wind, solar, nuclear, biomass and hydro. The carbon bands are GridMonkey's: very low under 70 g, low 70–139 g, moderate 140–219 g, high 220–299 g and very high 300 g or more, per kWh. Northern Ireland has its own grid and isn't included.
To see the grid now, open GridMonkey. For the wind farms that ran hardest this week, see the wind farm league table.
Data: NESO Carbon Intensity API (carbonintensity.org.uk), licensed under CC BY 4.0, recorded and summarised by GridMonkey. Figures as of 19 October 2026.