Wind farm operators have been paid more than £1 million since Christmas Eve to turn off their turbines.
The recent strong gales have forced several turbines to be shut down for safety reasons, with the National Grid forced to increase output from gas and coal fired power stations to make up the shortfall.
According to The Telegraph, one site, near Huddersfield, in Yorkshire, 110mph winds were so strong that 15ft blades were blown off three turbines.
On other occasions, often during periods when the wind is still strong but slightly less gusty, operators have been asked to turn off their turbines, because they were flooding the network with more electricity than was needed.
On the 23 occasions since Christmas Eve on which this has occurred, operators have received more than £1 million from the National Grid.
The so-called “constraint payments”, ultimately passed on to household bills, are paid to suppliers at times when the network is unable to absorb excess power being generated.
Critics say the impact of the strong winds revive concerns about the ability of wind farms to meet the country’s energy needs.
Dr Lee Moroney, planning director of the Renewable Energy Foundation, a think tank, said: “As we all know, wind is fickle, and balancing electricity supply and demand when there is too much or too little wind power is proving difficult and expensive.
“The costs, which are ultimately borne by consumers, will inevitably increase as more wind farms are built. REF has estimated that the total cost of solving the difficulties of integrating wind power will cost £5 billion a year on top of renewable subsidies in 2020 if current EU targets are met.”
When wind speeds reach 60mph, turbines automatically shut down. At one point on the morning January 3, as gales battered Britain, several turbines across the country were shut down at once, meaning the wind farms were only providing around a third of what they were expected to at the time. Around three quarters of those shut down were in Scotland, with the rest in England and Wales.
This left the National Grid with a shortfall of 2,500 megawatt hours - enough to power up to 1.6 million homes - which had to be made up by increasing the output from gas and coal fired power stations.
On these occasions, when turbines are shut for safety reasons, the operators do not receive any money. However, figures from the Renewable Energy Foundation, which has been critical of the scale of Britain’s adoption of wind power, also show that operators received 23 payments totalling £1,037,720, between Christmas Eve and January 4, to switch off their turbines at the behest of National Grid.
All were for wind farms in Scotland. The largest single payment in the period was for £95,136 to shut down turbines at the Hadyard Hill, near Girvan, in South Ayrshire, operated by Scottish and Southern Energy, on Boxing Day. Two other payments totalling £98,561 were made to stop turbines at the same site on different dates.
Nine payments, totalling £399,444 were made to shut turbines at the Farr wind farm, near Inverness, which is owned by RWE.
While coal and gas plants pay the grid to switch off because they save money by not generating fuel, wind farm operators demand compensation for “lost” subsidies.
A spokesman for the National Grid said: “The country’s demand and supply of electricity is balanced minute by minute. We also transport electricity from where it is generated to where it is needed, and as part of our role in managing the network we can ask generators to come on or off the grid to manage constraints and keep the system balanced. It’s a normal part of what we do every day.
“To put individual balancing costs into context, the overall cost for taking balancing actions for the financial year 2010/2011 was £708 million. These costs make up less than one per cent of customers’ bills.”
Robert Norris, from RenewableUK, the trade association representing the wind energy industry, said: “All power generators – including coal, gas and nuclear – receive these constraint payments when they’re told to shut down, to stop the grid being flooded with too much power.
“The fixed rate for nuclear power is £10,000 for every megawatt hour they’re not generating – far higher than the rates for wind. The Department of Energy and Climate Change says the majority of these payments go to coal-fired power stations and gas-fired power stations – only a tiny fraction goes to wind in comparison.
“The period in question, December 24th to January 4th, was exceptionally windy, so the £1 million payment received by wind generators during those twelve days is unrepresentative.
“We need to put that comparatively small figure into context – it’s important to look at how much those other power generators are being paid too, as they get far more than wind farm operators. We think the public deserves to know that.
“There’s a bigger question here too – why aren’t we investing more in upgrading the National Grid to accommodate all the energy that wind farms and other generators are providing? If we had a better grid, we could use all this energy – and even export it abroad to earn money for UK plc.
“Wind power supplied an average of 5.3 per cent of the UK’s demand for electricity from December 1st to January 5th, reaching a record share of 12.2 per cent on December 28th. As a result, carbon emissions from the UK’s other electricity generators were cut by over 750,000 tonnes.”
Winds on December 28 saw very strong winds in parts of northern Britain. Payments were made to stop turbines at three wind farms on that day.