Wind curtailment in May 2026
NESO turned down 577 GWh of wind in May 2026, 11% of what Britain’s grid-scale wind farms could have made. It paid wind farms a net £10.3m to hold back.
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Friday 29 May 2026
74 GWh of wind, stopped at the border
More than 99% of this wind was at Scottish wind farms. The farms could generate this power, but the lines that carry power to England were full. NESO paid the farms to reduce their output.
Most turned down that day
- 1Seagreenoffshore16 GWh
- 2Moray Eastoffshore16 GWh
- 3Moray Westoffshore14 GWh
- 4Vikingonshore6.6 GWh
- 5Dorenellonshore3.3 GWh
- 6North Kyleonshore1.6 GWh
Every half hour
When the wind was turned down
Each row is a day, midnight to midnight, UK time. The darker the cell, the more wind NESO turned down in that half hour. The amber bar is the day’s net cost. Choose a row to show that day on the map.
Delivered and turned down
What grid-scale wind farms made, and what they could have made
The wind farms on the transmission network, which Elexon meters. Solid: wind that reached the grid. Hatched: wind that the farms were paid to hold back. The full bar is what the farms could have made.
Wind farms
The wind farms that turned down the most
“Full-output hours” is the energy turned down divided by the farm’s size: the hours that the farm could have run flat out. Point at a farm to find it on the map.
| # | Wind farm | Turned down | GWh | Full-output hours | Net cost |
|---|---|---|---|---|---|
| 1 | Moray East Offshore · 900 MW | 171 | 190 | £1.74m | |
| 2 | Seagreen Offshore · 1,773 MW | 151 | 85 | £2.11m | |
| 3 | Moray West Offshore · 860 MW | 101 | 118 | £2.67m | |
| 4 | Viking Onshore · 487 MW | 86 | 177 | £1.26m | |
| 5 | Dorenell Onshore · 228 MW | 17 | 77 | £389k | |
| 6 | Limekiln Onshore · 106 MW | 8.2 | 77 | £245k | |
| 7 | Gordonbush Onshore · 145 MW | 6.1 | 42 | £157k | |
| 8 | Halsary Onshore · 30 MW | 5.4 | 179 | £61k | |
| 9 | North Kyle Onshore · 212 MW | 3.8 | 18 | £104k | |
| 10 | Creag Riabhach Onshore · 93 MW | 2.8 | 30 | £163k | |
| 11 | Glen Kyllachy Onshore · 52 MW | 2.1 | 41 | £87k | |
| 12 | Tom nan Clach Onshore · 40 MW | 1.5 | 38 | £105k | |
| 13 | South Kyle Onshore · 427 MW | 1.4 | 3 | £55k | |
| 14 | Edinbane Onshore · 41 MW | 1.3 | 33 | £148k | |
| 15 | Beinn an Tuirc Onshore · 96 MW | 1.2 | 12 | £14k | |
| 16 | Aikengall Onshore · 227 MW | 1.1 | 5 | £53k | |
| 17 | Neart na Gaoithe Offshore · 448 MW | 1.0 | 2 | £86k | |
| 18 | Cumberhead Onshore · 178 MW | 1.0 | 6 | £15k | |
| 19 | Windy Rig Onshore · 43 MW | 0.9 | 22 | £27k | |
| 20 | Stronelairg Onshore · 324 MW | 0.9 | 3 | £73k |
Questions
Questions about wind curtailment
What is wind curtailment?
Wind curtailment is when NESO, the operator of Great Britain’s grid, pays wind farms to make less power than the wind allows. The usual reason is that the wires cannot carry the power to where people use it. The wind farm offers a price to turn down (a bid), NESO accepts it, and the farm turns down.
How much wind was turned down in May 2026?
NESO turned down 577 GWh of wind in May 2026, at a net cost of £10.3m. That is 11% of what Britain’s grid-scale wind farms could have made. With the small wind farms on local networks included (a NESO estimate), it is 10% of all the wind. The most in one day was on Friday 29 May: 74 GWh, at a net cost of £1.79m.
Why is most curtailment in Scotland?
More than 99% of the wind turned down in May 2026 was at Scottish wind farms. Scotland has more wind power than it uses, and on windy days the wires that carry power south to England are full. The tightest point is the B6 boundary, the group of lines across the Scotland–England border. To keep supply and demand in balance, NESO then turns down wind in Scotland and turns up other power stations, often gas, in England.
Who pays for curtailment?
NESO pays the accepted bids and adds the cost to its balancing costs. Electricity suppliers pay those costs through the BSUoS charge and pass them on in household bills. Some wind farms with a Contract for Difference pay NESO to turn down instead, because they lose their subsidy when they do not generate. That is why the net cost of a day can be below zero.
Which wind farm was turned down the most in May 2026?
Moray East, an offshore wind farm in Scottish waters. It turned down 171 GWh, as much as 190 hours at full output, at a net cost of £1.74m.
Why is the share for grid-scale wind farms only?
The share is the curtailment rate: the energy turned down divided by what the same farms could have made (their output plus the energy turned down). NESO turns wind down through the Balancing Mechanism, where grid-scale wind farms on the transmission network take part, and Elexon meters their output. Small wind farms on local networks cannot be turned down in this way, and only NESO estimates of their output exist. So the rate counts grid-scale farms on both sides, and the share of all wind is given for context.
Why do these figures differ from other sources?
Sources count different things. Some count every balancing action, and some count only the payments to wind farms for transmission constraints. Some wait for the final settlement. These figures are indicative, and they count each accepted bid on a wind farm that NESO flagged as a system action.
Source
The Elexon settlement bid stack: each accepted bid on a wind unit that NESO flagged as a system action. Wind delivered is Elexon’s metered transmission wind (FUELINST). Farm positions come from the government’s Renewable Energy Planning Database; offshore positions are set by hand.
How we count it
Turned down is the volume of the accepted bids. Net cost is the volume times the bid price. The figures are indicative: Elexon revises them for a day or two, and the final settlement comes weeks later. More about the method.
Limits
The share turned down counts grid-scale wind farms only, on both sides of the sum: NESO cannot turn down small farms on the local networks in this way. A few small farms have no known position, so they are in the table but not on the map. Contains BMRS data © Elexon Limited and public sector information licensed under the Open Government Licence v3.0.