Data: Some wind farms generate just enough energy to boil a few kettles

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New figures show that, at times, some of the country's biggest wind farms have struggled to generate enough electricity to boil a few kettles.

The data released by RWE Energy showed at one point last week, three wind farms actually took electricity out of the National Grid rather than actually supplying it with energy.

The research showed at times many wind farms, such as those located at Little Cheyne Court and Trsglywn in Anglesey, Wales, produced less than one per cent of their maximum capacity.

Data shows at other points even in the same month however, the National Grid actually paid wind farm owners money in order to prevent the electricity supply system being overloaded. Known as constrain payments, these reached £7.5m for the first three weeks of August according to The Telegraph.

Renewable Energy Foundation director, John Constable, said: "Professional analysts have long known that fluctuating wind turbine output is poorly correlated with demand, but RWE's new website is a very valuable addition to the data available to the general public, and will encourage informed debate about the relative potential for different renewable technologies.

"The truth will be painful for some, but the facts have to be faced sooner or later."

The government has been pushing energy firms and homeowners to get more energy efficient. It has tried to promote the use of renewable energy such as wind energy in order to meet an EU target of providing at least 15% of a country's energy needs from such sources by 2020.

It also introduced its Green Deal in January, offering energy consumers the opportunity to take a loan out on energy-efficiency boosting measures such as the fitting of a new boiler or loft and wall insulation.

Dr Constable added: "The uncontrollably variable output of wind power already imposes significant grid and system management costs on the consumer, costs which are set to grow dramatically; we need to ask ourselves whether the EU renewables targets for 2020 are really affordable."

However, RenewableUK - the trade body of the wind industry - deputy chief executive, Maf Smith, hit back at the figures, suggesting they were an unfair representation of wind turbines as a whole.

He said: "You need to look at the year as a whole - the latest Government figures show that in 2012, more than 11% of the UK's electricity came from renewable sources, with wind providing the lion's share.

"We hit a new record in March when we generated enough electricity from wind at one point to power four out of 10 British homes.

"So while our critics may choose to pick out individual examples of periods when it was less windy, we prefer to look at the bigger picture as that's far more representative overall."

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