Most anti-wind coverage in the media stemmed from a report published by the Royal Academy of Engineering (RAE). It accuses the government's energy policy of being "hopelessly unrealistic" and expecting far too much from renewable energy sources. The academy is particularly critical of the results of the energy review published in February this year by Prime Minister Tony Blair's Performance and Innovation Unit (PIU).
The energy review's target of 20% of UK electricity from renewable energy sources by 2020 is over-optimistic, says RAE, and fails to deal with the fundamental problem with all renewable sources: they are intermittent. "Experience on the continent, especially in Denmark, has shown that grid stability can be adversely affected when the penetration of intermittent renewables reaches about 15%," says the report.
It attacks the energy review's "great faith" in wind energy, which proposes 22,000 MW of wind capacity by 2020. The engineers claim that because the wind is unreliable, this amount of capacity would only produce a power output of less than 7000 MW and would have to be backed up by 16-19,000 MW of conventional plant.
Energy consultant David Milborrow, who studied intermittency for the PIU energy review, counters that the RAE's contentious arguments about intermittency are basically flawed and not backed up with any evidence. It has chosen to disregard the findings in the PIU report on intermittency, he says.
"Numerous studies of the UK and Irish electricity networks have demonstrated that significant amounts of wind could be absorbed without excessive cost." Milborrow points out that for the 22,000 MW of wind proposed by the PIU, only around 1200 MW of extra back up would be needed -- less that 10% of the RAE's figures. He also points out that Denmark does not have problems of grid stability.
Energy heavyweight Shell has also waded into the argument on the side of wind. In its own submission to the energy review, it supports the PIU's recommended 20% target for renewables by 2020. Wind is the most promising energy source for the UK, it says, but getting planning consents for wind is a major constraint.
The British Wind Energy Association (BWEA), meanwhile, states that wind could make up the 7% shortfall in electricity supply by 2010 due to scheduled nuclear power station closures -- and at lowest cost to consumers. New BWEA figures show that at the rate of development planned by the wind industry, wind is likely to account for at least 8% of UK electricity in 2010. "The time has come to silence the claims for critics of wind power," says the BWEA. It points out that many bodies -- including National Grid Company -- accept that wind can provide at least 10% of total UK electricity supply without disrupting the system or requiring any back up. Though the BWEA declines to go for the exposed nuclear jugular, it nonetheless points out that wind plant in the UK generates electricity at some of the lowest prices in Europe.
Last month's £410 million government bail-out of financially stricken British Energy -- which supplies 20% of the country's electricity -- has given renewed impetus to calls by the green lobby for nuclear power to be phased out and replaced by renewables.
Greenpeace and renewable electricity supply company Ecotricity have gone a step further and challenged the legality of the government's nuclear loan. It was made without European Commission approval, they say, and is a flagrant breach of state aid law. They demand that the money is returned to the taxpayer immediately.
Dale Vince of Ecotricity says that if the wind industry was given the £410 million instead of British Energy, it could build enough onshore wind to power 10% of the country's needs. "Onshore wind energy is very competitive as well as being renewable, clean and safe; everything that nuclear is not," he says.