Cold realities of the wind farms that won't work when it snows

It wasn't so much the wrong type of snow, it was the fact it snowed at all.

When the country ground to a halt during weeks of sub-zero

temperatures, wind farms across the country came out in sympathy and their blades refused to budge.

The problem seems to be that the cold weather was accompanied by high pressure and a distinct lack of wind and meant at a time when even the most frugal were turning up the thermostat, one of the country's most controversial energy supplies all but dried up.

At its lowest ebb, figures show only 0.2 per cent of a possible five per cent of the UK's energy was being generated by turbines and, on average, they operated at just 16 per cent capacity throughout the cold spell.

With the turbines not turning, the country was forced to rely even more heavily on foreign pipelines and when those plans stalled, the National Grid had to ask its biggest users to ration supplies. A potential

crisis was quickly averted, but with the country set to increase its dependence on wind power, warning bells have now been sounded.

"At times of high demand in cold weather, there is a tendency for there to be no wind," says a spokesman for the Renewable Energy Foundation, an independent charity set up to encourage the development of renewable energy and energy conservation "It's an energy source which provides very little reliable capacity. It's not a problem at the moment because we have supplies of oil and gas from the North Sea, but further down the line, when 20 per cent of all our energy is being produced by renewables and we hit a similar weather pattern, then we will have a problem."

For sceptics, and there are many, the news a harsh winter can bring wind turbines to an involuntary standstill will provide yet another weapon in their armoury, but opponents also know it may be too late.

Despite vocal opposition, the Government recently unveiled a new wave of off-shore wind farms which they hope will create 70,000 so-called green collar jobs. The move came in the wake of new targets under which 6,400 turbines are supposed to provide a quarter of all the UK's energy needs by 2020.

However, the power generated from wind turbines is difficult to store and a back-up resource will always be needed to plug gaps in supplies. Plan B has been to rely on nuclear and coal-fired plants, but with the oldest sites due to be scrapped in five years' time as part of a European Union directive, less secure foreign pipelines, including those in Russia, will have to play an even bigger part in the UK's energy plans. While the inability of wind turbines to withstand a few days of frost may have handed detractors an easy stick with which to beat current plans, if this year's blip does turn in to a future energy crisis there would be little to laugh about.

Ofgem has already raised the possibility of a return to a three- day week within four years and many experts believe power cuts have only been avoided in recent months because the recession meant there was less demand than in good economic times.

"If the super wind farms proposed by the Government has already been in place this winter, they wouldn't have contributed anything of significance," says a spokesman for the Energy Intensive Users

Group. "The cold snap should be a warning that our power generation and gas supplies are under strain and it's getting worse.

"It will be industry which gets its gas switched off first. Just

imagine going through the winter we have had now when energy demand has gone back up to pre-recession levels."

While the UK doesn't have a good history of coping with sudden changes in weather, temperamental wind turbines have also been a source of embarrassment in the US. Minnesota recently bought 11 turbines from sun-blessed Palm Springs in California at a cost of $300,000 each. However, when temperatures plummeted recently, the special hydraulic fluid designed to keep the blades turning in cold weather failed.

Despite the mounting problems, it may take an even bigger crisis to

force another look at where next for wind farms.

"Energy policy never changes in advance of a crisis," says energy and economics specialist Professor Dieter Helm. "Sadly, it only ever changes after a crisis."