In March 2022, Britain's electricity averaged 186 gCO₂/kWh, in the moderate band (140–219 g). That is 46% dirtier than February 2022 (127 g), and about the same as March 2021 (185 g). Gas made 36.1% of the electricity generated, wind 23.6%, nuclear 17.5% and imports 9.1%; low-carbon sources together made 52.4%. The cleanest half hour was 39 g at 12:30 on Saturday 19 March, and the dirtiest 313 g at 21:00 on Thursday 24 March. The cleanest day was Saturday 19 March (63 g on average); the windiest was Friday 11 March (47.9% wind).
Carbon intensity, day by day
Day by day, as a table
| Day | gCO₂/kWh | Low-carbon | Wind | Solar | Gas | Half hours |
|---|---|---|---|---|---|---|
| Tue 1 Mar | 221 | 45.1% | 17.1% | 0.5% | 41.5% | 18 |
| Wed 2 Mar | 172 | 58.8% | 32.2% | 0.6% | 31.9% | 48 |
| Thu 3 Mar | 195 | 52.0% | 22.8% | 1.2% | 35.2% | 48 |
| Fri 4 Mar | 221 | 43.8% | 12.5% | 2.1% | 42.7% | 48 |
| Sat 5 Mar | 174 | 53.2% | 21.5% | 2.7% | 31.4% | 48 |
| Sun 6 Mar | 178 | 51.2% | 21.1% | 3.2% | 32.7% | 48 |
| Mon 7 Mar | 185 | 51.9% | 24.4% | 3.3% | 35.1% | 48 |
| Tue 8 Mar | 125 | 71.0% | 44.3% | 3.7% | 18.4% | 48 |
| Wed 9 Mar | 135 | 67.1% | 40.3% | 2.6% | 23.8% | 48 |
| Thu 10 Mar | 125 | 67.0% | 38.1% | 2.8% | 23.3% | 48 |
| Fri 11 Mar | 99 | 72.7% | 47.9% | 1.5% | 17.1% | 48 |
| Sat 12 Mar | 89 | 74.1% | 46.3% | 4.1% | 14.2% | 48 |
| Sun 13 Mar | 94 | 74.1% | 46.1% | 2.9% | 17.2% | 48 |
| Mon 14 Mar | 187 | 53.7% | 23.7% | 4.4% | 36.2% | 48 |
| Tue 15 Mar | 199 | 51.0% | 22.3% | 3.5% | 41.4% | 48 |
| Wed 16 Mar | 225 | 42.8% | 17.9% | 0.8% | 47.5% | 48 |
| Thu 17 Mar | 157 | 60.3% | 31.6% | 4.8% | 29.1% | 48 |
| Fri 18 Mar | 172 | 53.3% | 22.0% | 5.8% | 35.7% | 48 |
| Sat 19 Mar | 63 | 77.6% | 46.0% | 7.1% | 11.9% | 48 |
| Sun 20 Mar | 127 | 64.5% | 32.3% | 6.2% | 25.9% | 48 |
| Mon 21 Mar | 234 | 39.8% | 9.4% | 4.3% | 48.0% | 48 |
| Tue 22 Mar | 226 | 44.0% | 13.9% | 5.6% | 45.3% | 48 |
| Wed 23 Mar | 257 | 38.5% | 6.3% | 5.8% | 50.8% | 48 |
| Thu 24 Mar | 264 | 34.4% | 3.8% | 5.8% | 54.4% | 48 |
| Fri 25 Mar | 264 | 32.6% | 4.9% | 6.3% | 54.0% | 48 |
| Sat 26 Mar | 221 | 38.1% | 7.5% | 7.6% | 44.3% | 48 |
| Sun 27 Mar | 240 | 37.9% | 6.1% | 5.7% | 46.8% | 46 |
| Mon 28 Mar | 284 | 30.1% | 2.2% | 4.2% | 58.8% | 48 |
| Tue 29 Mar | 283 | 32.1% | 6.0% | 2.0% | 56.3% | 48 |
| Wed 30 Mar | 232 | 45.4% | 20.8% | 2.3% | 44.8% | 48 |
| Thu 31 Mar | 155 | 62.1% | 36.3% | 4.4% | 28.1% | 48 |
What powered the grid
Each fuel's average share of the electricity generated in Great Britain in March 2022, with March 2021 beneath it for comparison. Imports count as one source, as NESO counts them.
Hours in each carbon band
- Very low (under 70 g): 48 hours, 7%
- Low (70–139 g): 148 hours, 20%
- Moderate (140–219 g): 260 hours, 36%
- High (220–299 g): 261 hours, 36%
- Very high (300 g or more): 13 hours, 2%
Records in March 2022
- Cleanest half hour
- 39 g 12:30 on Saturday 19 March
- Dirtiest half hour
- 313 g 21:00 on Thursday 24 March
- Most wind
- 61.5% 04:30 on Sunday 13 March
- Most solar
- 25.1% 12:30 on Saturday 26 March
- Most low-carbon
- 88.2% 04:30 on Sunday 13 March
- Least gas
- 0.0% 23:00 on Thursday 10 March
- Cleanest day
- 63 g Saturday 19 March
- Dirtiest day
- 284 g Monday 28 March
- Windiest day
- 47.9% wind Friday 11 March
- Sunniest day
- 7.6% solar Saturday 26 March
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 26 October 2026.