Households paid Scottish wind farms not to produce 37 per cent of their planned electricity output during the first half of this year as the national grid did not have the capacity to move it to where it was needed.
Under government rules wind farms are paid to switch off if there is too much power being generated in certain parts of the country for Britain’s electricity grid to cope.
The development of wind farms, particularly in remote Scottish locations, has outpaced the capacity of the UK’s transmission network, meaning more and more money is being spent on paying wind farms to remain idle.
Latest figures from Octopus Energy suggest that so far this year British households paid almost £810 million in higher bills to pay for wind farms to switch off while paying gas plants to switch on in other parts of the country.
Analysis from the energy analytics company Montel, first reported by the Financial Times, found that in the first six months of this year four terawatt-hours of electricity produced by wind farms in northern Scotland was curtailed. This would have been enough to power all of Scotland’s households for the entire six-month period.
Wind farms in the area accounted for 86 per cent of the total 4.6 terawatt-hours of electricity curtailed across Britain, 15 per cent higher than in the same period last year.
The figures will increase concern about inefficiencies in the design of Britain’s rapidly evolving electricity system and the impact on all consumers’ energy bills. In particular there is a lack of capacity to move power from remote Scottish locations to urban centres in the south where most power is needed.
Ministers last month ruled out implementing a system called zonal pricing, in an attempt to combat the problem, after being warned by renewable energy generators that it would reduce investment in new offshore wind farms and jeopardise the government’s pledge of clean power by 2030.
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The increase comes as more wind farms have been developed in remote areas in Scotland, including in the Moray Firth off the northeast coast, where there is little demand for electricity and not yet enough cable capacity to move their output to consumers further south.
The wind farm in the Moray Firth
Power stations sell their output into the wholesale market regardless of where they are located, which in the case of wind farms often means they produce more than what can actually be used given grid constraints.
The government’s National Energy System Operator (Neso) steps in throughout the day to make sure generators are not producing more than the local grid can manage. The operator frequently pays wind farms in remote areas to switch off, while at the same time paying gas-fired generators in other parts of the country to increase their output.
Neso said it plays its part in keeping the costs of balancing the system as low as possible for customers, and that it had “saved consumers at least £1.2 billion over the past two years across the costs within our control”.
Gillian Martin, the Scottish energy secretary, said that the UK energy system is not fit for purpose
KEN JACK/GETTY IMAGES
But Pete Miller, the co-founder of Octopus Energy, said last month that it was “crazy to build wind farms where there’s no grid, then pay them to sit idle, and then pay the most expensive fossil fuel plants to generate the power instead”.
“We need to be clear that high electricity prices are the cost of a broken energy system,” he said.
The Department for Energy Security and Net Zero said Neso’s analysis had shown it was possible to produce clean and cheaper power by 2030 even when factoring in constraint payments. It added it was “delivering the biggest upgrade in Great Britain’s electricity network in decades, which will minimise constraint costs”.
Gillian Martin, the Scottish energy secretary, said: “I have been clear that the current UK energy system is not fit for purpose. Significant investment is required to achieve a clean power system.”