Updated
How clean the electricity is right now
Carbon intensity is the amount of CO₂ released to produce a unit of electricity. It falls when wind and nuclear dominate the mix, and rises when gas has to fill the gap.
In the half hour from 18:30 GMT on 7 November 2026, the carbon intensity of Great Britain's electricity was 260 gCO₂/kWh, rated very high. The cleanest time left today is forecast to be 23:30, at 247 gCO₂/kWh.
Right now · 18:30–19:00
260gCO₂/kWh
Very high intensity
9% higher than yesterday · 23% higher than a year ago
Cleanest time left today
23:30
247 gCO₂/kWh
A good window for heavy appliances
Cleanest half hour today
230gCO₂/kWh
At 11:30
Dirtiest half hour today
269gCO₂/kWh
At 06:30
Carbon intensity across today
Measured figures where the half hour has settled, alongside the forecast for the whole day.
View as table
| Half hour | Measured | Forecast | Index |
|---|---|---|---|
| 00:00–00:30 | 256 | 256 | Very high |
| 00:30–01:00 | 255 | 257 | Very high |
| 01:00–01:30 | 255 | 256 | Very high |
| 01:30–02:00 | 257 | 255 | Very high |
| 02:00–02:30 | 258 | 254 | Very high |
| 02:30–03:00 | 259 | 258 | Very high |
| 03:00–03:30 | 260 | 255 | Very high |
| 03:30–04:00 | 260 | 256 | Very high |
| 04:00–04:30 | 260 | 258 | Very high |
| 04:30–05:00 | 261 | 260 | Very high |
| 05:00–05:30 | 262 | 262 | Very high |
| 05:30–06:00 | 264 | 262 | Very high |
| 06:00–06:30 | 267 | 264 | Very high |
| 06:30–07:00 | 269 | 263 | Very high |
| 07:00–07:30 | 268 | 268 | Very high |
| 07:30–08:00 | 266 | 271 | Very high |
| 08:00–08:30 | 262 | 266 | Very high |
| 08:30–09:00 | 252 | 264 | Very high |
| 09:00–09:30 | 246 | 261 | Very high |
| 09:30–10:00 | 242 | 251 | Very high |
| 10:00–10:30 | 238 | 243 | Very high |
| 10:30–11:00 | 237 | 240 | Very high |
| 11:00–11:30 | 234 | 235 | Very high |
| 11:30–12:00 | 230 | 238 | Very high |
| 12:00–12:30 | 230 | 235 | Very high |
| 12:30–13:00 | 235 | 232 | Very high |
| 13:00–13:30 | 239 | 234 | Very high |
| 13:30–14:00 | 241 | 238 | Very high |
| 14:00–14:30 | 244 | 240 | Very high |
| 14:30–15:00 | 250 | 250 | Very high |
| 15:00–15:30 | 255 | 255 | Very high |
| 15:30–16:00 | 257 | 262 | Very high |
| 16:00–16:30 | 258 | 268 | Very high |
| 16:30–17:00 | 260 | 273 | Very high |
| 17:00–17:30 | 259 | 271 | Very high |
| 17:30–18:00 | 258 | 271 | Very high |
| 18:00–18:30 | 257 | 269 | Very high |
| 18:30–19:00 | 260 | 267 | Very high |
| 19:00–19:30 | - | 268 | Very high |
| 19:30–20:00 | - | 266 | Very high |
| 20:00–20:30 | - | 265 | Very high |
| 20:30–21:00 | - | 264 | Very high |
| 21:00–21:30 | - | 263 | Very high |
| 21:30–22:00 | - | 261 | Very high |
| 22:00–22:30 | - | 258 | Very high |
| 22:30–23:00 | - | 255 | Very high |
| 23:00–23:30 | - | 251 | Very high |
| 23:30–00:00 | - | 247 | Very high |
The next 48 hours
Forecast intensity ahead, for planning further out than the end of today.
View as table
| Half hour | Forecast | Band |
|---|---|---|
| Sat 18:30 | 260 | Very high |
| Sat 19:00 | 268 | Very high |
| Sat 19:30 | 266 | Very high |
| Sat 20:00 | 265 | Very high |
| Sat 20:30 | 264 | Very high |
| Sat 21:00 | 263 | Very high |
| Sat 21:30 | 261 | Very high |
| Sat 22:00 | 258 | Very high |
| Sat 22:30 | 255 | Very high |
| Sat 23:00 | 251 | Very high |
| Sat 23:30 | 247 | Very high |
| Sun 00:00 | 242 | Very high |
| Sun 00:30 | 239 | Very high |
| Sun 01:00 | 233 | Very high |
| Sun 01:30 | 230 | Very high |
| Sun 02:00 | 226 | High |
| Sun 02:30 | 228 | High |
| Sun 03:00 | 224 | High |
| Sun 03:30 | 220 | High |
| Sun 04:00 | 216 | High |
| Sun 04:30 | 213 | High |
| Sun 05:00 | 212 | High |
| Sun 05:30 | 209 | High |
| Sun 06:00 | 206 | High |
| Sun 06:30 | 208 | High |
| Sun 07:00 | 203 | High |
| Sun 07:30 | 199 | High |
| Sun 08:00 | 192 | High |
| Sun 08:30 | 188 | High |
| Sun 09:00 | 180 | High |
| Sun 09:30 | 175 | High |
| Sun 10:00 | 168 | Moderate |
| Sun 10:30 | 164 | Moderate |
| Sun 11:00 | 163 | Moderate |
| Sun 11:30 | 160 | Moderate |
| Sun 12:00 | 161 | Moderate |
| Sun 12:30 | 163 | Moderate |
| Sun 13:00 | 169 | Moderate |
| Sun 13:30 | 171 | High |
| Sun 14:00 | 174 | High |
| Sun 14:30 | 183 | High |
| Sun 15:00 | 195 | High |
| Sun 15:30 | 203 | High |
| Sun 16:00 | 208 | High |
| Sun 16:30 | 210 | High |
| Sun 17:00 | 212 | High |
| Sun 17:30 | 212 | High |
| Sun 18:00 | 210 | High |
| Sun 18:30 | 209 | High |
| Sun 19:00 | 209 | High |
| Sun 19:30 | 209 | High |
| Sun 20:00 | 209 | High |
| Sun 20:30 | 209 | High |
| Sun 21:00 | 210 | High |
| Sun 21:30 | 210 | High |
| Sun 22:00 | 210 | High |
| Sun 22:30 | 210 | High |
| Sun 23:00 | 213 | High |
| Sun 23:30 | 225 | High |
| Mon 00:00 | 221 | High |
| Mon 00:30 | 224 | High |
| Mon 01:00 | 225 | High |
| Mon 01:30 | 226 | High |
| Mon 02:00 | 224 | High |
| Mon 02:30 | 222 | High |
| Mon 03:00 | 222 | High |
| Mon 03:30 | 221 | High |
| Mon 04:00 | 225 | High |
| Mon 04:30 | 226 | High |
| Mon 05:00 | 226 | High |
| Mon 05:30 | 225 | High |
| Mon 06:00 | 225 | High |
| Mon 06:30 | 228 | High |
| Mon 07:00 | 230 | Very high |
| Mon 07:30 | 227 | High |
| Mon 08:00 | 221 | High |
| Mon 08:30 | 213 | High |
| Mon 09:00 | 201 | High |
| Mon 09:30 | 193 | High |
| Mon 10:00 | 186 | High |
| Mon 10:30 | 182 | High |
| Mon 11:00 | 180 | High |
| Mon 11:30 | 178 | High |
| Mon 12:00 | 178 | High |
| Mon 12:30 | 180 | High |
| Mon 13:00 | 181 | High |
| Mon 13:30 | 185 | High |
| Mon 14:00 | 191 | High |
| Mon 14:30 | 202 | High |
| Mon 15:00 | 211 | High |
| Mon 15:30 | 217 | High |
| Mon 16:00 | 217 | High |
| Mon 16:30 | 216 | High |
| Mon 17:00 | 214 | High |
| Mon 17:30 | 212 | High |
| Mon 18:00 | 210 | High |
| Mon 18:30 | 209 | High |
The cleanest window in the next two days starts tomorrow at 11:30 at 160 gCO₂/kWh. Running a wash, a dishwasher or an EV charge then does the least damage.
What this means
Carbon intensity measures how much CO₂ is released to produce each unit of electricity, in grams per kilowatt-hour. It rises and falls constantly, because the mix of generators running changes with the weather and with demand.
A windy night with strong nuclear output can drop below 50. A still, cold evening that needs every gas plant running can pass 300. The same kettle, boiled at different times of day, can be responsible for several times more emissions - which is what makes shifting flexible use worthwhile.
Figures cover Great Britain and account for imports across the interconnectors. Periods still to come are forecast, so they carry no measured value until the half hour has settled.
Common questions
What is carbon intensity?
How much CO₂ was released to make a unit of electricity, in grams per kilowatt-hour. Lower is cleaner.
When is the greenest time to use electricity?
There's no fixed answer, because it follows the weather. Windy spells and overnight hours are often good bets. The forecast on this page picks out the cleanest window for today and the next 48 hours.
Does shifting when I use electricity make a difference?
Yes. The same dishwasher cycle can cause several times the emissions on a still evening as on a windy night. It's most worthwhile for big loads like charging an EV.