In February 2024, Britain's electricity averaged 134 gCO₂/kWh, in the low band (70–139 g). That is 20% cleaner than January 2024 (167 g), and 19% cleaner than February 2023 (166 g). Wind made 36.0% of the electricity generated, gas 27.2%, imports 12.2% and nuclear 12.0%; low-carbon sources together made 59.7%. The cleanest half hour was 36 g at 12:00 on Sunday 4 February, and the dirtiest 271 g at 20:00 on Wednesday 7 February. Sunday 4 February was both the cleanest day (57 g on average) and the windiest (60.6% wind).
Carbon intensity, day by day
Day by day, as a table
| Day | gCO₂/kWh | Low-carbon | Wind | Solar | Gas | Half hours |
|---|---|---|---|---|---|---|
| Fri 2 Feb | 64 | 77.8% | 54.2% | 2.4% | 10.5% | 35 |
| Sat 3 Feb | 64 | 77.8% | 55.9% | 1.4% | 12.4% | 48 |
| Sun 4 Feb | 57 | 81.9% | 60.6% | 1.1% | 10.0% | 48 |
| Mon 5 Feb | 64 | 79.1% | 56.8% | 0.8% | 10.4% | 48 |
| Tue 6 Feb | 97 | 69.7% | 46.8% | 0.8% | 19.3% | 48 |
| Wed 7 Feb | 232 | 36.0% | 10.4% | 1.5% | 46.9% | 48 |
| Thu 8 Feb | 168 | 56.4% | 34.3% | 0.4% | 32.5% | 48 |
| Fri 9 Feb | 104 | 69.1% | 47.3% | 1.1% | 18.8% | 48 |
| Sat 10 Feb | 181 | 44.5% | 19.4% | 2.1% | 36.4% | 48 |
| Sun 11 Feb | 184 | 44.1% | 18.0% | 2.3% | 36.1% | 48 |
| Mon 12 Feb | 148 | 62.2% | 38.7% | 3.9% | 32.0% | 48 |
| Tue 13 Feb | 151 | 56.4% | 36.0% | 1.1% | 32.2% | 48 |
| Wed 14 Feb | 156 | 51.5% | 29.2% | 0.8% | 32.9% | 48 |
| Thu 15 Feb | 135 | 58.2% | 33.8% | 1.8% | 29.8% | 48 |
| Fri 16 Feb | 172 | 45.9% | 19.4% | 2.6% | 35.6% | 48 |
| Sat 17 Feb | 130 | 57.9% | 32.6% | 1.1% | 26.9% | 48 |
| Sun 18 Feb | 107 | 65.0% | 39.7% | 2.9% | 18.3% | 48 |
| Mon 19 Feb | 103 | 70.0% | 46.1% | 2.7% | 21.6% | 48 |
| Tue 20 Feb | 103 | 68.6% | 45.6% | 2.0% | 21.8% | 48 |
| Wed 21 Feb | 81 | 71.8% | 50.5% | 0.8% | 14.9% | 48 |
| Thu 22 Feb | 105 | 65.2% | 42.3% | 1.2% | 20.0% | 48 |
| Fri 23 Feb | 139 | 57.6% | 31.2% | 3.1% | 27.1% | 48 |
| Sat 24 Feb | 210 | 34.8% | 4.7% | 4.4% | 45.5% | 48 |
| Sun 25 Feb | 176 | 43.8% | 17.3% | 3.0% | 37.1% | 48 |
| Mon 26 Feb | 147 | 58.3% | 35.1% | 3.1% | 31.6% | 48 |
| Tue 27 Feb | 171 | 53.7% | 32.3% | 2.1% | 36.6% | 48 |
| Wed 28 Feb | 154 | 59.2% | 38.0% | 1.2% | 31.4% | 48 |
| Thu 29 Feb | 136 | 58.7% | 37.1% | 1.6% | 29.5% | 48 |
What powered the grid
Each fuel's average share of the electricity generated in Great Britain in February 2024, with February 2023 beneath it for comparison. Imports count as one source, as NESO counts them.
Hours in each carbon band
- Very low (under 70 g): 107 hours, 16%
- Low (70–139 g): 247 hours, 37%
- Moderate (140–219 g): 275 hours, 41%
- High (220–299 g): 38 hours, 6%
Records in February 2024
- Cleanest half hour
- 36 g 12:00 on Sunday 4 February
- Dirtiest half hour
- 271 g 20:00 on Wednesday 7 February
- Most wind
- 68.3% 04:30 on Tuesday 6 February
- Most solar
- 17.6% 11:00 on Saturday 24 February
- Most low-carbon
- 89.0% 04:30 on Tuesday 6 February
- Least gas
- 5.7% 12:00 on Sunday 4 February
- Cleanest day
- 57 g Sunday 4 February
- Dirtiest day
- 232 g Wednesday 7 February
- Windiest day
- 60.6% wind Sunday 4 February
- Sunniest day
- 4.4% solar Saturday 24 February
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.