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2026-11-03 03:46:14 GMT

Grid Curtailment: A price worth paying
Friends, I have become irritated by articles and YouTube videos telling me that it is bonkers that we pay wind farms to switch off their electricity generation (curtailment) when it becomes too windy. Here’s a typical example.
Click on image for a larger version.
The narrative of these articles is that we are paying renewable energy generators billions of pounds each year to switch off their wind turbines when their output would exceed the capacity of the grid to move the electricity across the network.
And the implication is that this is “bonkers” – the result of “Net Zero Zealots” – and that “something must be done” and that this is the reason that our electricity bills are so high.
This narrative is just wrong.
The actual situation is that these renewable generators are saving the UK billions of pounds a year by reducing our purchases of gas. Simultaneously this reduces – but does not eliminate – our exposure to the wild fluctuations in the global price of gas. But it does not reduce electricity prices because of the way the Electricity market is organised. Please allow me to explain.
The Big Picture
In order to incorporate renewable generation onto the grid – particularly wind – it is necessary to add grid connections from the wind farms to population centres. Logically this can happen in one of three ways.
The wind farms and grid connections are developed in synchrony.
The grid connections are built before the wind farms.
The grid connections are built after the wind farms.
What are the pros and cons of these options?
Option 1 would be ideal, but would involve larger and more complex projects: grid connections and wind farms are built by completely different companies and have different timescales: grid projects take 12 to 14 years whereas wind farms typically take half that.
Option 2 would not be an option for political reasons. It would involve spending billions of pounds to make grid connections which on completion would be literally useless.
Option 3 builds the generation which contributes to the grid using an existing but sub-optimal connection. Then – when generation has become a fact on the ground – the grid is improved to allow optimal generation.
In 2009 the UK chose Option 3 – a strategy called “connect and manage” as a pragmatic interim approach. Given the ongoing difficulty in creating grid infrastructure, this appears in retrospect to have been a reasonable choice.
The situation on the ground is complex for legal and technical and financial reasons, but simplifying, the “connect and manage” strategy has allowed the UK to add a great deal of wind generation relatively rapidly. This has reduced the country’s use of gas to generate electricity which has had two very positive consequences.
It has reduced the “gas bill” and our susceptibility to gas price shocks, such as from the wars in Ukraine and Iran.
It has reduced the carbon dioxide emissions associated with electricity generation from around 0.45 kgCO2 per kWh to around 0.15 kgCO2 per kWh.
Click on image for a larger version. Graph from Mygridgb.co.uk showing the annually averaged carbon intensity of UK electricity since 1998.
Curtailment Payments
In order to achieve these positive consequences the contracts with renewable generators were written to allow the generators to estimate their revenue independent of whether the grid connections – over which they had no control – were completed or not. This is where the curtailment payments come in: if the grid cannot manage the electricity that the generators would happily supply – then the generators receive compensation. One can argue whether or not this is reasonable, but I would say that it is not wholly unreasonable.
So the question is this: Do the curtailment payments to wind farms exceed the savings from not buying gas? The answer is no. And by a large margin. This article suggests that between 2010 and 2023, the connect and manage strategy saved the UK over £100 billion, despite paying out £42 billion in subsidies. The savings arise from the fact that we have avoided purchasing £133 billion of gas.
So why are Electricity Prices so high?
If generating electricity with wind rather than gas saves so much money, why is is this not reflected in cheaper prices?
This is a great question. And based on our normal “market experience” one might assume the savings would feed right through to the price. This does not happen.
Consider a simple case with generation only from wind (at £80/MWh) and gas (at £200/MWh). One might imagine that if wind supplied 50% of the electricity, with the balance from gas the system would charge customers the simple average price i.e. £140/MWh. And that if the wind fraction increased to 99% then the average price would be close to £80/MWh. Both these expectations are wrong.
This is because if the system needs any gas at all, then everyone gets paid the same price that gas asks for i.e. (£200 /MWh). This so-called “Merit-order” system is seen by economists as being optimal, but of course it is this system which leads to “bonkers prices.
This excellent analysis (Oct 2026) from Carbon brief explains that electricity prices are so high because of the continuing reliance on gas. It features this spectacular graph which shows just how closely electricity prices are linked to gas prices.
Click on image for a larger version. “Day-ahead “prices for wholesale gas (pence per therm) and electricity (£ per megawatt hour) in the UK for the period 2016 to 2026. As gas is slowly driven off the generation merit order, the price of electricity falls below the equivalent gas price. Source: Montel Online.
So electricity prices are high, but without wind energy, they would be higher still because as the need for gas generation is reduced, the most expensive gas generators are required only very rarely. You can see this happening in the graph above where in recent years it is becoming increasingly common for the electricity price to fall below the equivalent gas price.
And without wind generation the UK would be totally exposed to gas price fluctuations. Carbon Brief writes (27/10/26):
Since the start of the Iran war, the UK has avoided the need to import gas worth around £5.9bn as a result of record wind and solar output, according to previous Carbon Briefanalysis.
RenewableUK’s [Stephen] Agnew tells Carbon Brief: “Put simply, every wind turbine we build is gas we don’t need to buy.”
In addition to directly displacing gas, the windfarms on the system cut wholesale power prices by around a third in 2025, according to the Energy and Climate Intelligence Unit(ECIU).
This is due to the “merit-order effect”, whereby windfarms push the most expensive gas plants off the system, reducing the average wholesale power price.
Summary
The “Connect and Manage” strategy for bringing renewable generation onto the grid is not perfect but it has cleaned up our electricity supply dramatically.
Obviously it would have been better if the entirely privatised National Grid plc had spent more resources investing in the UK Grid rather than expanding abroad.
But the system has nonetheless delivered reduced costs to the country, even if those costs are not reflected in the price of electricity because of the merit-order pricing system.
https://protonsforbreakfast.wpcomstaging.com/2026/11/02/grid-curtailment-a-price-worth-paying/
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