The Carbon Trust's findings deal a blow to government renewable energy policy. It is assisting micro-wind generation in urban and other areas through grants and by making planning consent easier to obtain for domestic wind turbines. Small wind turbines in rural areas, where wind speeds are higher, fare better in the Carbon Trust report. They can provide up to four times the electricity and carbon savings as small generators mounted on rooftops and other structures in urban areas. Electricity from small rural turbines -- with rated capacities less than 50 kW -- can be cheaper than from the grid.
The Carbon Trust's report is based on extensive research by the UK Meteorological Office and environmental and engineering consultant group Entec. It finds that small wind could provide up to 1.5 TWh of power each year, enough to meet 0.4% of UK electricity consumption and save the release of 0.6 million tonnes of carbon dioxide. This assumes 10% of households installing turbines that can produce electricity at a cost that is competitive with electricity from the grid. The price of grid electricity for consumers is currently around £0.12/kWh.
The Carbon Trust, which is funded by the central and national governments of the UK, recommends that only small turbines that will save "reasonable" amounts of carbon should benefit from grants in future. Manufacturers should adopt carbon labelling for their products, enabling customers to estimate the lifecycle emissions of their turbines. It also calls for higher height limits of more than 11 metres to blade tip for stand-alone rural turbines under permitted development rights to maximise energy output and carbon savings.
Later this year, the Carbon Trust is to launch a web-based tool to help organisations evaluate conditions and potential energy yields at their sites. It will include wind speed data from the National Climate Information Centre, part of the Meteorological Office.
Vital people understand
The Carbon Trust's Mark Williamson says enquiries from organisations about small wind generators are increasing. "It's vital that people understand the wind resources available to them, and we hope they find the guidance in our report useful. As one of a number of micro-generation technologies with a role to play in our future energy supply, we also believe it is essential that government policies and public funding encourage carbon savings from small wind turbines most effectively. This is why we're making recommendations about grant support and planning."
The British Wind Energy Association (BWEA) focuses on the positive aspects of the report, pointing out that it finds nearly two million homes and businesses could benefit from small wind systems. With the technology cost of small wind generators reducing while fossil fuel prices continuing to rise, the potential for small wind is only going to grow, it says. "Micro and small wind is the only micro-generation technology in which the UK currently holds world leadership," says the BWEA's Alex Murley. "With over 14 British manufacturers, currently experiencing annual domestic market growth of over 80%, as well as expanding export trade, this emerging UK industry could deliver tens of thousands of jobs as well as make valuable contribution in helping consumers to cutting carbon emissions and generate their own clean renewable energy."