Turbines produce only about a quarter of maximum output – and consumers pay heavily
Chris Benfield Science and Technology Correspondent
WINDFARMS are failing to produce as much power as they are supposed to – and the only way to make them more efficient is to site them in beauty spots.
Research by the Yorkshire Post has revealed that the turbines are producing only about a quarter of the maximum output they were designed for – and the only ones that really work are those high on the hills and coastlines.
Analysis of the production from wind turbines last year shows they are falling short of the hopes that Labour had for them as a way of reducing carbon dioxide (CO2) emissions.
The poor performance is rev-ealed by figures that show how much power they are actually producing, compared to what they could theoretically produce. This is known as the "load factor".
Coal-burning power stations manage about 90 per cent of their theoretical maximums. So do gas burners and nuclear stations.
But performance figures for a sample of 12 substantial wind-farms show half scored less than 25 per cent last year. The average was 27 per cent.
To achieve 100 per cent efficiency, the wind would have to blow at 30mph for 24 hours a day, 365 days a year.
But crucial Government decisions were made on the expectation of load factors of between 30 and 35 per cent.
Its Energy White Paper pledged support worth 1bn a year to the development of renewable energy sources – which include wave, solar and wind power – by 2010.
The Government started the dash to build windfarms by making electricity companies subsid-ise power production from renew-able sources, to cut down on CO2.
The cost of the "renewables" drive is a hidden tax, passed on to the customer in rising bills.
At the heart of the scheme is a trade in Renewables Obligation Certificates (ROCs), issued for one megawatt of electricity flow over one hour from an approved source, such as a windfarm – much more expensive than electricity from established sources.
Before the ROC system came into force the Government relied on estimates from the wind industry – and even now the British Wind Energy Association produces figures on the basis of 30 per cent load factors. But now it is possible to check the theory against the issue of ROCs.
The Yorkshire Post research was done with help from the Renewable Energy Foundation, set up by Devonshire-based entertainments tycoon Noel Edmonds, to argue that wind was not always the best of the alternative energy options.
The organisation's research director, John Constable, says: "Your figures are consistent with some that we had already worked out. DTI figures have suggested a national average of just over 24 per cent in 2003, and everything we have seen since suggests that that figure is about right.
"The difference between that and the 30 per cent assumption is significant. It means you need 1,500 more turbines to hit Government targets and would add 1bn or more to the capital investment required.
"This makes the CO2 reduction and the electricity extremely expensive. The industry is 70 per cent subsidised, so the consumer has a right to ask for value for money. Wind has a role, but we probably have to scale back our expectations."
Some windfarms are hitting the targets. Of the six in the sample from Yorkshire and Lincolnshire, four did better than 30 per cent and one, at Mable-thorpe, averaged 35 per cent.
But the figures from inland, and further south, and summer months, bring the average down. The exceptions to the rule are on our coasts and hills – just where objectors do not want them to be.
Yorkshire's most profitable tur-
bines are at Out Newton on Spurn Head, with sea on three sides and a load factor of 33 per cent. Inland, the Ovenden Moor windfarm, high on the Pennines, above Halifax, manages 31 per cent.
But the turbines on Royd Moor in South Yorkshire, near Penistone, score 22.5 per cent and Yorkshire Water's small installation at Chelker Reservoir, near Addingham, between Ilkley and Skipton, only 20 per cent.
Between them the Yorkshire four and Lincolnshire two manage an average load factor of 28 per cent at best. And our survey sup-
ports the contention that the figure is lower over the UK as a whole.
Wind supporters point out that the technology is improving all the time. And Denmark and Germany live with load factors of only 20 per cent and 16 per cent.
John McDougall, a former power-station designer who is Professor of Sustainability at Sheffield Hallam University, said: "I can't see that a few percentage points either way make a jot of difference to the idea that as wind power is free you grab as much of it as you can.
"The figures will get better because of the experience we are gaining. Once a 1MW turbine was big. Soon 5MW will be standard. We have done work which suggests you could get up to 10MW."
The figures will be hotly debated in the test-case inquiry into proposals for a big wind-farm at Whinash, on the edge of the Lake District National Park.