In November 2019, Britain's electricity averaged 240 gCO₂/kWh, in the high band (220–299 g). That is 19% dirtier than October 2019 (202 g). Gas made 41.4% of the electricity generated, nuclear 19.9%, wind 17.3% and biomass 7.6%; low-carbon sources together made 47.1%. The cleanest half hour was 83 g at 03:00 on Saturday 2 November, and the dirtiest 372 g at 06:30 on Tuesday 19 November. The cleanest day was Saturday 2 November (157 g on average); the windiest was Monday 11 November (29.9% wind).
Carbon intensity, day by day
Day by day, as a table
| Day | gCO₂/kWh | Low-carbon | Wind | Solar | Gas | Half hours |
|---|---|---|---|---|---|---|
| Fri 1 Nov | 202 | 50.3% | 19.7% | 0.5% | 39.0% | 48 |
| Sat 2 Nov | 157 | 61.3% | 27.6% | 1.0% | 28.1% | 48 |
| Sun 3 Nov | 208 | 52.0% | 17.5% | 1.8% | 36.8% | 48 |
| Mon 4 Nov | 245 | 45.8% | 15.0% | 1.5% | 40.7% | 48 |
| Tue 5 Nov | 245 | 46.5% | 16.3% | 1.1% | 43.5% | 48 |
| Wed 6 Nov | 290 | 35.4% | 5.8% | 1.2% | 52.8% | 48 |
| Thu 7 Nov | 209 | 52.6% | 22.5% | 1.5% | 36.0% | 48 |
| Fri 8 Nov | 249 | 45.1% | 14.7% | 1.6% | 44.9% | 48 |
| Sat 9 Nov | 225 | 45.7% | 15.2% | 1.2% | 41.7% | 48 |
| Sun 10 Nov | 226 | 46.5% | 13.3% | 2.5% | 41.8% | 48 |
| Mon 11 Nov | 180 | 60.1% | 29.9% | 1.8% | 29.5% | 48 |
| Tue 12 Nov | 194 | 57.3% | 29.0% | 1.3% | 33.3% | 48 |
| Wed 13 Nov | 298 | 37.8% | 10.6% | 1.6% | 48.2% | 48 |
| Thu 14 Nov | 255 | 47.8% | 21.9% | 0.7% | 40.9% | 48 |
| Fri 15 Nov | 263 | 47.1% | 21.1% | 0.6% | 42.0% | 48 |
| Sat 16 Nov | 295 | 33.5% | 6.5% | 1.1% | 53.6% | 48 |
| Sun 17 Nov | 293 | 34.3% | 8.0% | 0.9% | 52.6% | 48 |
| Mon 18 Nov | 295 | 40.1% | 13.1% | 2.2% | 50.0% | 48 |
| Tue 19 Nov | 318 | 37.1% | 10.8% | 1.0% | 53.1% | 48 |
| Wed 20 Nov | 248 | 49.8% | 24.0% | 1.0% | 42.4% | 48 |
| Thu 21 Nov | 220 | 53.0% | 26.3% | 0.3% | 38.5% | 48 |
| Fri 22 Nov | 215 | 51.5% | 21.8% | 0.5% | 36.7% | 48 |
| Sat 23 Nov | 187 | 56.7% | 24.5% | 0.2% | 32.9% | 48 |
| Sun 24 Nov | 248 | 44.0% | 10.9% | 0.4% | 42.9% | 48 |
| Mon 25 Nov | 250 | 45.9% | 14.7% | 0.3% | 41.6% | 48 |
| Tue 26 Nov | 215 | 52.6% | 20.7% | 0.5% | 34.6% | 48 |
| Wed 27 Nov | 241 | 47.8% | 16.6% | 0.5% | 39.2% | 48 |
| Thu 28 Nov | 209 | 54.0% | 23.1% | 0.7% | 34.2% | 48 |
| Fri 29 Nov | 271 | 41.5% | 9.3% | 1.9% | 45.7% | 48 |
| Sat 30 Nov | 259 | 40.6% | 7.0% | 1.3% | 45.6% | 48 |
What powered the grid
Each fuel's average share of the electricity generated in Great Britain in November 2019, with October 2019 beneath it for comparison. Imports count as one source, as NESO counts them.
Hours in each carbon band
- Low (70–139 g): 35 hours, 5%
- Moderate (140–219 g): 208 hours, 29%
- High (220–299 g): 381 hours, 53%
- Very high (300 g or more): 97 hours, 13%
Records in November 2019
- Cleanest half hour
- 83 g 03:00 on Saturday 2 November
- Dirtiest half hour
- 372 g 06:30 on Tuesday 19 November
- Most wind
- 41.1% 04:00 on Tuesday 12 November
- Most solar
- 13.1% 11:30 on Sunday 10 November
- Most low-carbon
- 79.0% 04:00 on Saturday 2 November
- Least gas
- 12.3% 00:30 on Saturday 2 November
- Cleanest day
- 157 g Saturday 2 November
- Dirtiest day
- 318 g Tuesday 19 November
- Windiest day
- 29.9% wind Monday 11 November
- Sunniest day
- 2.5% solar Sunday 10 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 30 October 2026.