A new monthly record was set in September this year, when £28,434,560 was paid out by National Grid to stop electricity generation. Most cash was paid to Scottish wind farms, with some earning more than £1m a month for not supplying power.
Whitelee and its extension on the outskirts of Glasgow, the biggest onshore wind farm in the UK, has received almost a fifth of the entire pot since 2010, with payments totalling more than £96m to date.
Meanwhile, the 350MW Clyde scheme, near Abington in South Lanarkshire, has raked in more than £64m and the Griffin, near Aberfeldy in Perthshire, nearly £32m.
The amount paid out has been rising annually, despite a new transmission cable to export power from Scotland south of the Border.
The fees, known as constraint payments, are paid for by households across the UK.
Anti-wind campaigners say spending on constraints has got “completely out of control”, and described expansion of the industry as “reckless”.
Lyndsey Ward, who lives in the Highlands, said: “The constraints situation is completely out of control. The Scottish Government is recklessly approving more and more turbines to be connected to a grid that has little hope of managing any power they produce.
“The result is an ever-increasing number of turbines have to be switched off and it is the consumer who pays.
“Industry also has the wind costs on their energy bills and they add that on to the goods and services they sell us.”
The £1.2 billion Western Link interconnector, which became operational last year, runs 260 miles underwater from Hunterston in Ayrshire to Connah’s Quay in North Wales.
It was hoped by exporting power to England and Wales the cable would cut levels of compensation paid to energy firms when Scottish turbines have to be shut down because supply outstrips demand.
But faults have seen the cable – a joint project between network operators National Grid and Scottish Power Transmission – unable to operate at full capacity until last month.
So far there seems no reduction in payouts compared to the same time last year.
Dr John Constable is director of the Renewable Energy Foundation, a charity which first exposed constraint payments to wind generators and publishes data on the costs.
He said: “No-one expected the Western Link to be a complete solution to wind power constraint costs, but the continuing level of payments is strikingly high – £9m in November, £5.5m in December so far – raising the question as to whether this very expensive interconnector represents value for money.”
Energy regulator Ofgem approved the Western Link project following a cost-benefit analysis that showed it would reduce consumer bills.
A spokeswoman for National Grid said: “The Western Link project is playing a vital role in reinforcing the existing UK transmission system … The project is in the early days of operation but will significantly reduce the levels of constraint payments being made to wind generators.”
A spokesman for Ofgem added: “Ofgem sets National Grid, as electricity system operator, strong financial incentives to manage constraint costs efficiently. Overall these costs are less than 1 per cent of a typical household electricity bill.”