A record £3.1million was paid to wind farms in the space of one day for switching off turbines when it became too windy.
The compensatory sum was handed to operators on Saturday because electricity supply outstripped demand.
In exceptionally windy conditions, the National Grid cannot cope with the extra energy turbines produce, so firms receive ‘constraint payments’ to temporarily shut them down.
Research by the Renewable Energy Foundation (REF), the charity that is critical of subsidies for wind power, found that energy companies have been paid £395million over the past eight years to stop their Scottish wind farms operating.
The figures emerged as it was revealed that a £1billion sub-sea cable to transfer surplus renewable energy south of the Border is not currently functioning.
By exporting electricity to England and Wales, it was hoped that the cable would cut the amount of compensation paid to energy companies when their Scottish wind farms have to be shut down, but it is out of action due to a ‘fault’.
Last night, Scottish Tory energy spokesman Alexander Burnett said: ‘Our bills are high enough already without having to pay more for turning off wind turbines.
‘Given the costs involved in not having this interconnector working, you would expect it to be repaired as soon as possible. Many people will rightly ask why nothing has been resolved when the fault was discovered months ago.’
The REF said £3.1million was paid out in constraint payments on Saturday – an all-time daily record. The constraint cash is paid by the National Grid but is ultimately charged to consumers and added to power bills.
The Western Link sub-sea cable, running 239 miles under the sea from Hunterston, Ayrshire to the Wirral, in North-West England, has been ‘offline’ since spring, when a fault was found during tests.
The interconnector began oper- ating at 50 per cent capacity last winter but then a fault was found in a stretch of the cable in Liverpool Bay. It is expected to be back in operation at full capacity in September.
John Constable of the REF, which first revealed wind constraint payments and their cost, said: ‘Since 2010, the total cost to consumers of constraint payments to Scottish wind power companies for reducing output is about £395million.
‘The Western Link interconnector from Hunterston to Deeside was intended to reduce this cost, though its own £1billion capital expenditure has to be recovered from consumers, making it an expensive solution.
‘Interconnectors were supposed to put an end to the scandal of constraint payments. This clearly isn’t happening, a fact which raises questions as to whether interconnectors, such as the Western Link, will ever fully address the problem of excess wind power in Scotland.’
A Western Link spokesman said: ‘The link has been in operation over the winter of 2017-18, helping to reduce constraint costs and was taken offline in spring 2018 for final commissioning tests.
‘During this final stage of testing, a cable fault was detected in Liverpool Bay.
‘This is under repair with a plan to be through final testing in September 2018. At that stage, we expect that the link will be operating at full capacity, delivering significant power transfer capability from Scotland to England and Wales.
‘The Western Link project is a global-leading project of this type and will be a major asset to Britain’s energy infrastructure.
‘Although the delay is unfortunate, the Western Link will deliver benefits for power generators and consumers for decades to come.’
‘Our bills are high enough already’