The short version
The latest wind curtailment 2025 figures put constraint payments at approximately £1.5 billion, according to reporting on National Grid ESO (NESO) balancing data. Scotland now builds more wind capacity than the transmission lines south into England can carry at peak output, so the grid operator pays wind farms to switch off and gas plants further south to switch on instead - households cover both sides of that trade.
None of this shows up as a separate line item, since it is folded into balancing costs, one of the non-commodity charges layered into your standing charge and unit rate. The government's pylon and grid investment programme is meant to fix the underlying bottleneck, on a timeline running to the end of the decade, not the next billing cycle. Ofgem announces the Q4 2026 price cap on 26 August, and network cost allowances are worth watching within it.
How SwitchInsights tracked this
This analysis draws on National Grid ESO constraint payment reporting, Ofgem's RIIO-T3 transmission settlement and Ofgem price cap documentation.
Wind curtailment explained: the Scotland England transmission bottleneck
Curtailment happens when a generator can produce power but the network cannot move it to where demand sits. Britain's wind capacity has grown fastest in Scotland, while demand is heaviest in England, and the cables connecting the two were not built for today's volume of wind.
On a high-wind day, National Grid ESO pays Scottish wind farms a fee to reduce output, then pays a gas plant closer to demand to cover the shortfall - so curtailing "free" wind power is effectively paid for twice. That differs from the issue in our explainer on why gas still sets UK electricity prices, which concerns electricity that reaches the market, not power that cannot get there at all.
Constraint payments energy bill impact: how the cost reaches you
Constraint payments are recovered through balancing costs, sitting inside the non-commodity portion of every household bill alongside network and policy costs. Suppliers such as Octopus Energy and British Gas do not set these costs themselves - Ofgem sets the allowance suppliers may recover, and it passes through largely unchanged across the standing charge and unit rate. Our standing charge increase 2026 explainer and network charges update 2026 cover the wider picture in more detail.
Worked example: standing charge constraint payments
Ofgem does not routinely break out the domestic-only share of constraint costs, so we have modelled an estimate using the stated assumptions below.
| Step | Assumption or figure |
|---|---|
| Total 2025 constraint payments | £1.5 billion |
| Domestic share of GB electricity demand | ~35% |
| Domestic-attributable curtailment cost | ~£525 million |
| UK domestic electricity accounts | ~28 million |
| Estimated cost per household, 2025 | ~£19/year |
Against a typical £200 electricity standing charge, that £19 works out to close to a tenth of the fixed fee - and alongside the transmission uplift covered in our network charges update 2026, together account for roughly two-fifths of it.
SwitchInsights estimates, is curtailment
once to switch wind off, once for gas instead
Pounds for pylons and the grid investment programme UK timeline
The structural fix is new transmission capacity between Scotland and England, not compensation payments. New pylons face years of local opposition, which is where the government's pounds for pylons scheme comes in: households within 500 metres of new lines can claim money off their bills to speed up planning, though the scheme only accelerates approval - it does not touch curtailment costs directly. Targets call for the network to roughly double in capacity by 2030, with the RIIO-T3 settlement funding construction through 2031, so meaningful relief remains a matter of years, not months.
The Ofgem grid connection meeting: does it signal faster reform?
Ofgem convened generators, network companies and suppliers for the grid connection meeting in August 2026, continuing a push to clear the queue of projects waiting for a date to join the network. Grid connection reform UK plans speed up that queue - a different problem from curtailment, which affects wind farms already connected in Scotland with no room left on the cables south.
Clearing the queue faster does not, on its own, add transmission capacity, and Ofgem has not confirmed which way its conclusions point - so this is one to watch, not a fix already delivered. Compare current deals on the SwitchPilot tariff tracker meanwhile.
Wind curtailment update: will the Ofgem price cap 26 August move network costs?
The Q4 2026 price cap announcement on 26 August sets tariff levels for October to December. The headline unit rate typically moves with wholesale gas and electricity prices, unrelated to curtailment, while network cost allowances - the component carrying constraint payments - are usually confirmed on a longer annual cycle, not reset every quarter. Watch for whether Ofgem has adjusted the network cost allowance 2026 baseline set out in our standing charge increase 2026 explainer.
SwitchInsights' take
Wind curtailment is a symptom of building generation faster than the grid to carry it, and £1.5 billion a year is the current price of that mismatch - one more likely to sit inside your standing charge than disappear from it soon. The SwitchPilot tariff tracker covers what is available to switch to now.
Wind curtailment costs 2025 UK: FAQ
What is wind curtailment?
The grid operator pays a wind farm to switch off, usually because the network cannot carry all its power, and pays a gas plant closer to demand to switch on instead.
How does wind curtailment affect bills?
Curtailment payments are folded into balancing costs and passed on across the standing charge and unit rate as part of every household bill.
How much did wind curtailment cost UK bill payers in 2025?
Constraint payments to curtail wind generation reached approximately £1.5 billion across 2025, covering both the switch-off and replacement-generation payments.
Will pounds for pylons reduce wind curtailment costs?
Not directly - it speeds up planning approval near new pylons, while the actual fix is the transmission capacity those pylons carry.
When is the Q4 2026 energy price cap announced?
Ofgem announces the Q4 2026 price cap, covering October to December, on 26 August 2026.