Wind turbines like David Cameron's 'don't provide much electricity'

Wind turbines mounted on town houses like David Cameron’s often do not provide a great deal of electricity because of a lack of wind in urban areas, according to research into the new technology.

By Louise Gray, Environment CorrespondentLast Updated: 11:51PM GMT 12 Jan 2009

Rising electricity costs and concern over climate change has led thousands of people to install wind turbines on their houses, including the leader of the Conservative Party at his home in Notting Hill, west London.
Manufacturers claim some of the new micro turbines can provide 30 per cent of a household’s electricity needs. However, the most wide-ranging study to be carried out in the UK so far found that on average the wind turbines only generate 214 watt hours per day, including when the turbine is switched off for maintenance or due to failure. This is enough electricity to power four low energy lightbulbs for a day or less than five per cent of a household’s daily electricity needs.
The study by consultant engineers Encraft found only wind turbines on buildings in exposed positions or high up away from other buildings generated a substantial amount of energy. But the wind energy industry questioned the validity of the study and said wind turbines could still generate valuable amounts of electricity if put up in the right place.
Encraft monitored electricity output from 26 building-mounted wind turbines from leading manufacturers installed on homes from Cornwall to North East Scotland.
There are currently 6,500 small and micro wind turbines in the UK, with thousands more set to be installed this year. The turbines are on sale at leading DIY stores from around £1,500. Some manufacturers claim the technology can provide a third of a household’s electricity needs and cut household bills.
However the year-long study found that on average, including when the turbine was switched off for maintenance or broken, each turbine generated 214 watt hours per day. This would provide less than five per cent of a household’s electricity needs and save just £33.
The best performing turbine on top of a ten storey building in the midlands provided enough energy to power a house for the day but another turbine on a low rise a few miles away did not even generate enough electricity to run the turbine’s electronics.
Matthew Rhodes, managing director of Encraft, said manufacturers need to provide clearer information on siting wind turbines.
“While we expected the trial results to be somewhat below manufacturer claims, we have been taken aback by the magnitude of the discrepancy, and are disappointed that the results of the trial suggest that micro wind is suited only to tall buildings and coastal sites,” he said.
But Alex Murley, of the British Wind Energy Association, said small and micro wind turbines could provide more than 10 per cent of the UK’s electricity needs if sited correctly.
He said: “Although this may be the first trial to look at micro-wind turbines within urban environments, low samples sizes, extremely poor sighting and patchy data renders the trial unrepresentative of the wider sector. Clearly micro-wind turbines do not work everywhere, but the UK is the windiest country in Europe, and there are literally millions of excellent sites waiting for sensible application of this successful technology – If correctly sited and installed, micro-wind turbines can cut bills, cut carbon and deliver real economic, and environment benefits.”