Wind farms have been paid to refrain from producing up to half of the electricity they are capable of generating, according to research that led MPs to warn that “inappropriate” decisions on wind power were “forcing excess costs onto consumers”.

An analysis found that, in 2020, three large wind farms in Scotland were paid a total of £24.5 million to fail to produce about half of their potential output.

Researchers said the “constraint payments”, which are ultimately added to consumer bills, were being fuelled by a high concentration of onshore wind farms in Scotland often leaving the electricity grid unable to cope on windy days.

The Renewable Energy Foundation, a charity that publishes energy data, said the problem would continue until  “until there is more than sufficient interconnection between Scotland and the centres of demand in England”. The analysis comes ahead of an expected spike in electricity bills.

Craig Mackinlay, who leads the Net Zero Scrutiny Group of Conservative MPs, said the constraint payments were an example of unnecessary costs being charged to consumers.

A government spokesman insisted the payments were “not a viable income stream for onshore wind developers”, but a new analysis by REF found some individual wind farms were agreeing to not produce up to half of their potential output in order to avoid overwhelming the grid.

Excess costs ‘forced onto consumers’

In one case, £7.7 million in “constraint payments”  handed to the operator of a 23-turbine scheme in Scotland in 2020 led to the wind farm deliberately failing to produce 51 per cent of its potential output. In another, SSE, the operator of the 33-turbine Strathy North wind farm in the Highlands, was paid £5.9 million to avoid producing 48 per cent of its capacity.

Last year, which saw particularly low wind speeds, the 59-turbine Dorenell wind farm in Moray, owned by EDF Renewables, was paid £1.5 million to avoid producing a total of 179 gigawatt hours – 35 per cent of its potential output.

Dr Lee Moroney, REF’s principle analyst, said: “When wind farms have been so poorly sited that they are discarding up to 50 per cent of their annual output, the public has every right to ask how on Earth these projects came to get planning permission.”

Mr Mackinlay said turbines appeared to be constructed “in inappropriate locations, forcing excess costs onto consumers and harming our precious natural heritage in the process”.

More renewables ‘will protect customers’

A government spokesman said: “Gas is expensive and wind power is cheap, so we need more renewables to protect consumers. Constraint payments remain the most efficient option for National Grid to keep Britain’s lights on, and are only used when there is excess supply.” 

A spokesman for EDF Renewables said it had to respond to National Grid’s constraint requests “in order to manage the system and keep the lights on”.

Alistair Phillips-Davies, the chief executive of SSE, said: “Wind will end up generating most of the energy the country needs, and the best resource is in Scotland. Britain needs more wind power to minimise our reliance on volatile international gas markets.”

Scottish Renewables, a trade body, said constraint payments added just £1 per year to the average household electrical bill.

On Friday, about 40 per cent of the day’s electricity supply was generated by  turbines – far higher than average – amid the strong winds brought by Storm Eunice.