Roof-mounted wind turbines ‘no help in reducing carbon’

Ben Webster, Environment Editor

Roof-mounted wind turbines and solar panels are “eco-bling” that allow their owners to flaunt their green credentials but contribute very little towards meeting Britain’s carbon reduction targets, according to the Royal Academy of Engineering.
Developers will waste millions of pounds installing such micro-generation devices unless the Government revises its building regulations on carbon-neutral homes and offices.
Doug King, Professor of Building Engineering at the University of Bath and the author of a report on low carbon buildings published today, said that far greater savings could be made by installing better insulation and methods of trapping the Sun’s rays.
He proposed that the government target for all new homes to be carbon-neutral by 2016 should be relaxed in return for developers making equivalent contributions to wind farms and other large-scale renewable energy projects. “Wind turbines and solar cells on the roof achieve little or nothing and are what I describe as eco-bling. It’s just about trying to say to the general public, ‘I’m being good, I’m helping the environment’.

“The things that save the money are not done, because they are not sexy.”
Dr King said that wind turbines on urban homes often consumed more energy than they generated.
Field trials carried out last year by the government-funded Energy Saving Trust found that the most productive building-mounted wind turbines in urban or suburban areas generated only £26 of electricity a year. Many of these turbines, which cost about £1,500, were net consumers of electricity because their controls drew power from the grid when the wind was low.
David Cameron installed a wind turbine on the roof of his home in West London but was forced to remove it because he had not obtained planning permission. His spokeswoman said yesterday that the turbine had been returned to the architect. “The technology has moved on so there was no point in putting it back up,” she said.
Professor King said that for wind turbines on urban homes to be effective, they would have to be so big that their vibration would damage the building. He said that installing microgeneration devices could cost £10,000 to £12,000 per home and reduce its emissions by only a few per cent. He proposed an alternative policy under which developers would offset the entire emissions of new homes by contributing £3,000 per dwelling towards a wind farm on a hilltop.
Professor King said that offices would need to be redesigned to reduce energy use and cope with regular power cuts caused by the failure to replace ageing power stations. He accused the Government of failing to practise what it preached on emissions. A recent National Audit Office report found that 80 per cent of government buildings opened since 2002 fell below minimum environmental performance standards.
Running out of puff
1.9% of homes (455,000) are suitable for building-mounted turbines
5m a second minimum average wind speed to justify the cost of a small turbine
80% by 2050: target for cut in 1990 level of greenhouse gas emissions
2016 date for all new homes to be zero-carbon under target
45% of current emissions come from buildings
80% of the buildings in which we will live in 2050 have been built
Sources: DECC, Energy Saving Trust, Royal Academy of Engineering