In June 2024, Britain's electricity averaged 100 gCO₂/kWh, in the low band (70–139 g). That is 19% cleaner than May 2024 (124 g), and 40% cleaner than June 2023 (167 g). Wind made 26.3% of the electricity generated, gas 20.6%, nuclear 18.3% and imports 17.0%; low-carbon sources together made 62.4%. The cleanest half hour was 14 g at 13:00 on Tuesday 4 June, and the dirtiest 207 g at 20:30 on Wednesday 12 June. The cleanest day was Saturday 8 June (59 g on average); the windiest was Friday 28 June (45.4% wind).
Carbon intensity, day by day
Day by day, as a table
| Day | gCO₂/kWh | Low-carbon | Wind | Solar | Gas | Half hours |
|---|---|---|---|---|---|---|
| Sat 1 Jun | 61 | 69.2% | 33.3% | 12.9% | 13.3% | 33 |
| Sun 2 Jun | 78 | 66.1% | 25.4% | 13.4% | 15.5% | 48 |
| Mon 3 Jun | 126 | 56.3% | 23.4% | 6.8% | 28.6% | 48 |
| Tue 4 Jun | 65 | 72.1% | 42.1% | 5.2% | 13.5% | 48 |
| Wed 5 Jun | 60 | 73.5% | 41.1% | 10.0% | 11.8% | 48 |
| Thu 6 Jun | 89 | 62.4% | 26.0% | 9.4% | 18.2% | 48 |
| Fri 7 Jun | 64 | 69.8% | 37.2% | 8.3% | 13.1% | 48 |
| Sat 8 Jun | 59 | 73.9% | 40.0% | 11.7% | 12.0% | 48 |
| Sun 9 Jun | 72 | 69.1% | 38.0% | 8.3% | 15.4% | 48 |
| Mon 10 Jun | 67 | 71.7% | 38.5% | 8.8% | 10.9% | 48 |
| Tue 11 Jun | 105 | 66.1% | 27.6% | 11.0% | 13.2% | 48 |
| Wed 12 Jun | 192 | 41.6% | 6.9% | 9.9% | 44.6% | 17 |
| Thu 13 Jun | 116 | 59.3% | 30.2% | 5.3% | 26.8% | 48 |
| Fri 14 Jun | 91 | 67.5% | 34.0% | 8.2% | 18.6% | 48 |
| Sat 15 Jun | 116 | 59.2% | 21.3% | 8.6% | 19.5% | 48 |
| Sun 16 Jun | 78 | 68.6% | 31.3% | 10.4% | 12.0% | 48 |
| Mon 17 Jun | 129 | 56.9% | 18.6% | 9.9% | 26.3% | 48 |
| Tue 18 Jun | 150 | 52.7% | 15.6% | 8.8% | 32.3% | 48 |
| Wed 19 Jun | 123 | 54.2% | 16.8% | 10.2% | 26.0% | 48 |
| Thu 20 Jun | 139 | 50.7% | 11.9% | 11.0% | 31.8% | 48 |
| Fri 21 Jun | 89 | 65.7% | 28.0% | 10.1% | 19.2% | 48 |
| Sat 22 Jun | 86 | 60.7% | 21.0% | 11.1% | 17.1% | 48 |
| Sun 23 Jun | 105 | 54.9% | 14.2% | 10.4% | 21.8% | 48 |
| Mon 24 Jun | 136 | 52.5% | 13.8% | 9.7% | 27.9% | 48 |
| Tue 25 Jun | 157 | 48.4% | 9.4% | 10.1% | 34.9% | 48 |
| Wed 26 Jun | 152 | 50.3% | 12.6% | 10.8% | 35.2% | 48 |
| Thu 27 Jun | 71 | 75.2% | 41.4% | 9.1% | 15.5% | 48 |
| Fri 28 Jun | 73 | 77.2% | 45.4% | 8.1% | 15.4% | 48 |
| Sat 29 Jun | 93 | 59.0% | 18.8% | 11.1% | 18.3% | 48 |
| Sun 30 Jun | 99 | 58.6% | 19.7% | 7.2% | 19.4% | 48 |
What powered the grid
Each fuel's average share of the electricity generated in Great Britain in June 2024, with June 2023 beneath it for comparison. Imports count as one source, as NESO counts them.
Hours in each carbon band
- Very low (under 70 g): 186 hours, 27%
- Low (70–139 g): 385 hours, 55%
- Moderate (140–219 g): 126 hours, 18%
Records in June 2024
- Cleanest half hour
- 14 g 13:00 on Tuesday 4 June
- Dirtiest half hour
- 207 g 20:30 on Wednesday 12 June
- Most wind
- 64.8% 02:30 on Friday 28 June
- Most solar
- 80.7% 05:00 on Saturday 8 June
- Most low-carbon
- 95.2% 05:00 on Saturday 8 June
- Least gas
- 1.9% 05:00 on Saturday 8 June
- Cleanest day
- 59 g Saturday 8 June
- Dirtiest day
- 157 g Tuesday 25 June
- Windiest day
- 45.4% wind Friday 28 June
- Sunniest day
- 13.4% solar Sunday 2 June
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 21 October 2026.