The cost of switching off wind farms because Britain’s electricity grid cannot carry their power has reached just over £1.51bn so far this year, exceeding the £1.47bn spent in the whole of 2025, according to a tracker run by Octopus Energy.
September was the costliest month on record at £404.3m and included seven of the most expensive days recorded, the household energy supplier’s Wasted Wind tracker shows. The highest daily figure came on Wednesday, when £30m was paid out to energy companies for constraints related to wind farms, Octopus said.
Of this year’s total, £1.28bn has been spent paying gas-fired power plants near urban areas to fire up, the tracker shows. They replace wind turbines in remote locations that must be turned off because of a lack of grid capacity.
The payments are made by the National Energy System Operator (Neso), which has to keep supply and demand balanced across the electricity network in real time. The costs it incurs in doing so are levied on households and businesses through their energy bills.
High gas prices resulting from the US war on Iran have pushed up the running costs of gas plants, increasing the sums Neso has to pay them.
The bill has also risen because some existing power lines have been taken out of action for upgrades. Octopus said some crucial transmission points in Scotland were operating at only 40 per cent of capacity because of temporary outages for that work.
Balancing the system has become more difficult as large new wind farms have connected to the grid in remote locations, often in Scotland, without the network upgrades needed to transmit their power to consumers.
Total costs of dealing with all cabling constraints were about £2.2bn in the year to June, and Neso has forecast that this will rise to £3.2bn over the 12 months to July 2027. The vast majority relates to wind farms being switched off, although other power plants are also constrained at times.
A £70bn programme of network upgrades is under way to try to resolve the issue, but many of the projects are running late.
The National Audit Office warned on 11 September that the total constraints bill could hit £7.8bn by the end of the decade, equating to about £100 on a typical annual energy bill.
Octopus lobbied unsuccessfully for Britain to introduce regional wholesale electricity pricing, which would force generators to take account of network constraints and prevent them selling power if the grid could not cope. The government ruled this out last year.
Greg Jackson, founder of Octopus Energy, said: “We’ve already blown past last year’s entire bill, and customers are paying every pound of that waste. It’s madness.
“We’re spending billions to build more grid, while failing to use our existing infrastructure more efficiently. Instead of paying to throw away homegrown cheap power, we should be using it to bring bills down for households and businesses.”
A spokeswoman for the Department of Energy Security and Net Zero said: “Britain’s outdated grid is holding the country back. New wind farms, solar projects and businesses are stuck waiting years for connections, keeping us reliant on global fossil fuels and driving up costs for households.
“That’s why we’re tackling decades of historic underinvestment by reforming the connections queue, launching Great British Grid to unlock billions of pounds of public and private investment, and ending the red tape that slows projects down by allowing developers to build their own connections.”
