Wind curtailment
How much GB wind gets switched off
When the grid cannot carry everything the wind is producing, the system operator pays wind farms to hold back. This is the running tally of that lost energy - measured in megawatt-hours, not pounds, and counted from the balancing instructions themselves.
The tally
- Aug 2026
- 303.6 GWh
- 2026
- 6.9 TWh
- All time
- 43.9 TWh
Wind energy held below plan, in UTC calendar buckets. Transmission-connected wind only, so every figure is a lower bound. Snapshot taken 15 Aug 2026 · 09:48 UTC.
Curtailed energy by month
The monthly chart loads in your browser.
Each bar is one UTC calendar month of curtailed wind, and the ledger runs from Jan 2017 to Aug 2026. Months the ledger has not reached are absent rather than drawn as a zero.
Worst-hit wind farms
| # | Wind farm | Curtailed | Share |
|---|---|---|---|
| 1 | Seagreen6 units | 8.9 TWh | 20.2% |
| 2 | Moray Offshore Windfarm West Limited7 units | 8.6 TWh | 19.5% |
| 3 | Viking Wind Farm4 units | 2.3 TWh | 5.2% |
| 4 | Dorenell2 units | 1.6 TWh | 3.6% |
| 5 | Whitelee I2 units | 1.3 TWh | 3.0% |
| 6 | Stronelairg Wind Farm3 units | 1.0 TWh | 2.4% |
| 7 | Beatrice Offshore windfarm4 units | 990.8 GWh | 2.3% |
| 8 | Kilgallioch Windfarm | 987.0 GWh | 2.2% |
| 9 | Bhlaraidh Windfarm 1 | 849.9 GWh | 1.9% |
| 10 | Griffin Wind Farm2 units | 701.9 GWh | 1.6% |
Curtailed wind by farm, over all time. Share is of all curtailment in that window, not of the rows listed. Where a farm runs several balancing units they roll up into one row; a unit we cannot match to a station keeps its own code.
How this is measured
Every time the system operator accepts a bid to turn a generator down, Elexon publishes the instruction. For a wind farm we compare the instructed level against what that farm told the market it was about to generate - its physical notification - and the shortfall is curtailed output. We sample that difference every minute and add it up into half-hours, so an instruction that ramps, or that a later instruction supersedes part-way through, contributes only the minutes it actually covered.
The result is a lower bound, and deliberately so. Only transmission-connected wind farms appear in the balancing data; embedded wind on the distribution networks is invisible to it. Read these figures as "at least this much", never as the national total.
The ledger is energy, never money. What curtailment costs consumers depends on settlement data with no free, keyless feed, so putting a pound figure on these megawatt-hours would mean inventing one. The same numbers drive two entries on the all-time records board.
Computed from Elexon BMRS balancing acceptances and physical notifications, retrieved through the keyless Insights API and republished under the Open Government Licence v3.0. The ledger starts at 1 January 2017. Page baked 15 Aug 2026 · 09:48 UTC.