In November 2020, Britain's electricity averaged 177 gCO₂/kWh, in the moderate band (140–219 g). That is 11% dirtier than October 2020 (160 g), and 26% cleaner than November 2019 (240 g). Gas made 36.7% of the electricity generated, wind 22.9%, nuclear 19.8% and imports 7.9%; low-carbon sources together made 54.1%. The cleanest half hour was 55 g at 03:00 on Thursday 12 November, and the dirtiest 329 g at 07:30 on Friday 27 November. Sunday 1 November was both the cleanest day (94 g on average) and the windiest (39.8% wind).
Carbon intensity, day by day
Day by day, as a table
| Day | gCO₂/kWh | Low-carbon | Wind | Solar | Gas | Half hours |
|---|---|---|---|---|---|---|
| Sun 1 Nov | 94 | 72.3% | 39.8% | 1.2% | 20.7% | 48 |
| Mon 2 Nov | 126 | 67.0% | 35.3% | 2.7% | 25.4% | 48 |
| Tue 3 Nov | 166 | 55.3% | 25.6% | 2.1% | 37.2% | 48 |
| Wed 4 Nov | 233 | 44.0% | 13.7% | 3.1% | 45.5% | 48 |
| Thu 5 Nov | 243 | 39.7% | 9.4% | 2.1% | 48.0% | 48 |
| Fri 6 Nov | 234 | 42.0% | 9.4% | 2.7% | 46.2% | 48 |
| Sat 7 Nov | 216 | 41.8% | 7.9% | 2.3% | 46.1% | 48 |
| Sun 8 Nov | 201 | 46.6% | 12.9% | 0.8% | 39.4% | 48 |
| Mon 9 Nov | 240 | 37.8% | 7.2% | 0.9% | 49.2% | 48 |
| Tue 10 Nov | 228 | 40.7% | 11.5% | 1.4% | 48.3% | 48 |
| Wed 11 Nov | 141 | 58.9% | 30.3% | 0.6% | 31.6% | 48 |
| Thu 12 Nov | 120 | 66.2% | 35.0% | 2.5% | 26.1% | 48 |
| Fri 13 Nov | 132 | 62.8% | 32.7% | 2.2% | 29.3% | 48 |
| Sat 14 Nov | 107 | 66.6% | 37.4% | 0.3% | 23.3% | 48 |
| Sun 15 Nov | 95 | 71.4% | 39.8% | 1.9% | 21.0% | 48 |
| Mon 16 Nov | 121 | 66.7% | 37.6% | 0.9% | 24.6% | 48 |
| Tue 17 Nov | 118 | 68.8% | 37.6% | 0.7% | 23.1% | 48 |
| Wed 18 Nov | 109 | 70.3% | 37.6% | 0.8% | 21.7% | 48 |
| Thu 19 Nov | 163 | 57.6% | 26.4% | 1.9% | 34.0% | 48 |
| Fri 20 Nov | 173 | 55.6% | 24.4% | 0.5% | 35.3% | 48 |
| Sat 21 Nov | 111 | 69.8% | 38.0% | 0.9% | 24.1% | 48 |
| Sun 22 Nov | 152 | 61.7% | 28.3% | 2.0% | 30.6% | 48 |
| Mon 23 Nov | 180 | 56.5% | 24.2% | 1.4% | 36.3% | 48 |
| Tue 24 Nov | 162 | 60.5% | 30.2% | 1.0% | 32.4% | 48 |
| Wed 25 Nov | 228 | 45.2% | 13.9% | 0.7% | 45.4% | 48 |
| Thu 26 Nov | 279 | 33.7% | 2.3% | 1.4% | 56.6% | 48 |
| Fri 27 Nov | 282 | 33.2% | 3.2% | 1.1% | 56.4% | 48 |
| Sat 28 Nov | 227 | 38.6% | 7.7% | 0.5% | 51.7% | 48 |
| Sun 29 Nov | 237 | 37.3% | 5.0% | 0.5% | 51.0% | 48 |
| Mon 30 Nov | 185 | 54.8% | 23.9% | 0.3% | 40.1% | 48 |
What powered the grid
Each fuel's average share of the electricity generated in Great Britain in November 2020, with November 2019 beneath it for comparison. Imports count as one source, as NESO counts them.
Hours in each carbon band
- Very low (under 70 g): 14 hours, 2%
- Low (70–139 g): 239 hours, 33%
- Moderate (140–219 g): 250 hours, 35%
- High (220–299 g): 204 hours, 28%
- Very high (300 g or more): 14 hours, 2%
Records in November 2020
- Cleanest half hour
- 55 g 03:00 on Thursday 12 November
- Dirtiest half hour
- 329 g 07:30 on Friday 27 November
- Most wind
- 49.6% 03:30 on Thursday 12 November
- Most solar
- 14.9% 11:30 on Wednesday 4 November
- Most low-carbon
- 85.8% 04:30 on Thursday 12 November
- Least gas
- 11.4% 03:30 on Thursday 12 November
- Cleanest day
- 94 g Sunday 1 November
- Dirtiest day
- 282 g Friday 27 November
- Windiest day
- 39.8% wind Sunday 1 November
- Sunniest day
- 3.1% solar Wednesday 4 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 28 October 2026.