In November 2023, Britain's electricity averaged 161 gCO₂/kWh, in the moderate band (140–219 g). That is 16% dirtier than October 2023 (139 g), and 5% cleaner than November 2022 (169 g). Wind made 32.6% of the electricity generated, gas 30.9%, nuclear 12.4% and imports 10.8%; low-carbon sources together made 55.9%. The cleanest half hour was 49 g at 13:00 on Wednesday 1 November, and the dirtiest 307 g at 06:00 on Friday 17 November. The cleanest day was Wednesday 1 November (75 g on average); the windiest was Thursday 23 November (57.4% wind).
Carbon intensity, day by day
Day by day, as a table
| Day | gCO₂/kWh | Low-carbon | Wind | Solar | Gas | Half hours |
|---|---|---|---|---|---|---|
| Wed 1 Nov | 75 | 73.9% | 50.0% | 1.9% | 12.9% | 48 |
| Thu 2 Nov | 85 | 68.3% | 46.2% | 0.7% | 18.5% | 48 |
| Fri 3 Nov | 102 | 69.7% | 43.4% | 2.7% | 19.4% | 48 |
| Sat 4 Nov | 166 | 48.3% | 25.6% | 1.6% | 28.0% | 48 |
| Sun 5 Nov | 154 | 51.1% | 27.4% | 3.2% | 26.7% | 48 |
| Mon 6 Nov | 131 | 62.1% | 36.5% | 2.8% | 22.5% | 48 |
| Tue 7 Nov | 140 | 60.2% | 34.7% | 2.7% | 26.6% | 48 |
| Wed 8 Nov | 123 | 64.6% | 41.0% | 0.9% | 20.2% | 48 |
| Thu 9 Nov | 154 | 55.5% | 30.2% | 1.9% | 27.5% | 48 |
| Fri 10 Nov | 170 | 51.5% | 25.6% | 2.2% | 30.2% | 48 |
| Sat 11 Nov | 188 | 47.9% | 19.4% | 3.1% | 33.1% | 48 |
| Sun 12 Nov | 181 | 49.2% | 22.7% | 0.9% | 31.9% | 48 |
| Mon 13 Nov | 90 | 72.2% | 49.9% | 1.7% | 16.5% | 48 |
| Tue 14 Nov | 140 | 59.4% | 37.7% | 0.9% | 28.1% | 48 |
| Wed 15 Nov | 172 | 58.3% | 35.0% | 2.0% | 34.5% | 48 |
| Thu 16 Nov | 284 | 27.8% | 5.6% | 0.6% | 56.8% | 48 |
| Fri 17 Nov | 264 | 33.6% | 10.4% | 2.2% | 54.7% | 48 |
| Sat 18 Nov | 81 | 76.0% | 57.3% | 0.6% | 13.5% | 48 |
| Sun 19 Nov | 93 | 73.3% | 54.3% | 1.0% | 14.8% | 48 |
| Mon 20 Nov | 179 | 55.8% | 34.5% | 1.3% | 34.4% | 48 |
| Tue 21 Nov | 213 | 50.5% | 28.2% | 0.8% | 42.7% | 48 |
| Wed 22 Nov | 151 | 64.0% | 43.4% | 0.6% | 27.3% | 48 |
| Thu 23 Nov | 78 | 78.8% | 57.4% | 1.6% | 12.5% | 48 |
| Fri 24 Nov | 105 | 70.8% | 48.1% | 1.8% | 17.2% | 48 |
| Sat 25 Nov | 168 | 51.3% | 27.5% | 2.7% | 32.4% | 48 |
| Sun 26 Nov | 230 | 34.4% | 10.3% | 0.5% | 50.1% | 48 |
| Mon 27 Nov | 196 | 47.7% | 25.5% | 0.6% | 40.6% | 48 |
| Tue 28 Nov | 212 | 45.7% | 22.1% | 1.8% | 42.9% | 48 |
| Wed 29 Nov | 249 | 37.6% | 13.6% | 1.6% | 52.1% | 48 |
| Thu 30 Nov | 268 | 37.1% | 14.4% | 1.3% | 59.2% | 48 |
What powered the grid
Each fuel's average share of the electricity generated in Great Britain in November 2023, with November 2022 beneath it for comparison. Imports count as one source, as NESO counts them.
Hours in each carbon band
- Very low (under 70 g): 64 hours, 9%
- Low (70–139 g): 236 hours, 33%
- Moderate (140–219 g): 249 hours, 35%
- High (220–299 g): 170 hours, 24%
- Very high (300 g or more): 2 hours, 0%
Records in November 2023
- Cleanest half hour
- 49 g 13:00 on Wednesday 1 November
- Dirtiest half hour
- 307 g 06:00 on Friday 17 November
- Most wind
- 70.0% 03:00 on Sunday 19 November
- Most solar
- 15.2% 11:00 on Sunday 5 November
- Most low-carbon
- 88.5% 02:30 on Friday 24 November
- Least gas
- 6.9% 22:00 on Thursday 23 November
- Cleanest day
- 75 g Wednesday 1 November
- Dirtiest day
- 284 g Thursday 16 November
- Windiest day
- 57.4% wind Thursday 23 November
- Sunniest day
- 3.2% solar Sunday 5 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 22 October 2026.