In July 2026, Britain's electricity averaged 122 gCO₂/kWh, in the low band (70–139 g). That is 8% cleaner than June 2026 (132 g), and 5% cleaner than July 2025 (129 g). Wind made 23.9% of the electricity generated, gas 23.0%, imports 17.4% and solar 13.7%; low-carbon sources together made 57.1%. The cleanest half hour was 37 g at 13:30 on Saturday 4 July, and the dirtiest 240 g at 02:00 on Wednesday 1 July. The cleanest day was Saturday 4 July (58 g on average); the windiest was Thursday 2 July (47.6% wind).
Carbon intensity, day by day
Day by day, as a table
| Day | gCO₂/kWh | Low-carbon | Wind | Solar | Gas | Half hours |
|---|---|---|---|---|---|---|
| Wed 1 Jul | 179 | 43.9% | 15.5% | 11.0% | 38.8% | 48 |
| Thu 2 Jul | 74 | 75.1% | 47.6% | 13.2% | 14.3% | 48 |
| Fri 3 Jul | 90 | 61.9% | 26.7% | 15.8% | 14.2% | 48 |
| Sat 4 Jul | 58 | 73.3% | 46.4% | 11.9% | 9.9% | 48 |
| Sun 5 Jul | 87 | 61.4% | 29.5% | 14.0% | 14.0% | 48 |
| Mon 6 Jul | 79 | 68.5% | 38.7% | 13.8% | 13.5% | 48 |
| Tue 7 Jul | 105 | 59.3% | 27.2% | 14.7% | 18.9% | 48 |
| Wed 8 Jul | 174 | 42.1% | 9.5% | 14.8% | 37.0% | 48 |
| Thu 9 Jul | 185 | 39.6% | 7.2% | 15.1% | 39.4% | 48 |
| Fri 10 Jul | 185 | 40.6% | 8.4% | 14.9% | 40.4% | 48 |
| Sat 11 Jul | 130 | 52.6% | 17.2% | 17.2% | 25.8% | 48 |
| Sun 12 Jul | 83 | 67.0% | 31.3% | 17.4% | 13.6% | 48 |
| Mon 13 Jul | 104 | 64.2% | 29.6% | 14.8% | 19.1% | 48 |
| Tue 14 Jul | 123 | 60.6% | 25.8% | 14.5% | 23.9% | 48 |
| Wed 15 Jul | 158 | 52.4% | 16.5% | 14.9% | 33.3% | 48 |
| Thu 16 Jul | 178 | 46.7% | 10.4% | 14.9% | 37.8% | 48 |
| Fri 17 Jul | 163 | 50.3% | 13.7% | 15.2% | 34.1% | 48 |
| Sat 18 Jul | 86 | 64.0% | 29.4% | 13.5% | 12.0% | 48 |
| Sun 19 Jul | 83 | 63.0% | 27.2% | 16.0% | 11.5% | 48 |
| Mon 20 Jul | 123 | 52.6% | 15.2% | 15.2% | 20.0% | 48 |
| Tue 21 Jul | 137 | 51.1% | 16.3% | 12.7% | 25.9% | 48 |
| Wed 22 Jul | 134 | 52.4% | 17.3% | 12.5% | 24.1% | 48 |
| Thu 23 Jul | 132 | 53.0% | 18.9% | 11.7% | 23.8% | 48 |
| Fri 24 Jul | 115 | 58.6% | 23.8% | 14.0% | 21.0% | 48 |
| Sat 25 Jul | 77 | 71.8% | 39.2% | 13.4% | 12.4% | 48 |
| Sun 26 Jul | 66 | 71.6% | 42.5% | 10.4% | 9.2% | 48 |
| Mon 27 Jul | 103 | 59.8% | 27.6% | 11.2% | 15.2% | 48 |
| Tue 28 Jul | 105 | 60.3% | 29.7% | 11.5% | 18.2% | 48 |
| Wed 29 Jul | 153 | 49.4% | 17.4% | 12.5% | 30.8% | 48 |
| Thu 30 Jul | 148 | 50.5% | 18.5% | 9.7% | 29.1% | 48 |
| Fri 31 Jul | 149 | 52.3% | 17.4% | 13.6% | 30.3% | 48 |
What powered the grid
Each fuel's average share of the electricity generated in Great Britain in July 2026, with July 2025 beneath it for comparison. Imports count as one source, as NESO counts them.
Hours in each carbon band
- Very low (under 70 g): 140 hours, 19%
- Low (70–139 g): 334 hours, 45%
- Moderate (140–219 g): 233 hours, 31%
- High (220–299 g): 39 hours, 5%
Records in July 2026
- Cleanest half hour
- 37 g 13:30 on Saturday 4 July
- Dirtiest half hour
- 240 g 02:00 on Wednesday 1 July
- Most wind
- 66.2% 03:30 on Thursday 2 July
- Most solar
- 43.7% 13:00 on Saturday 11 July
- Most low-carbon
- 89.0% 13:30 on Saturday 25 July
- Least gas
- 4.4% 13:00 on Tuesday 7 July
- Cleanest day
- 58 g Saturday 4 July
- Dirtiest day
- 185 g Thursday 9 July
- Windiest day
- 47.6% wind Thursday 2 July
- Sunniest day
- 17.4% solar Sunday 12 July
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 17 October 2026.