Data essential for good turbine performance

22 January 2009

Wind-speed data, and not optimism, is needed if a small wind turbine is to produce enough electricity.

A study by the British Wind Energy Association found that too many buyers and installers of small building-mounted wind turbines put their faith in the gods when it comes to having their machine operate efficiently.

As a result only five of the 26 sites where turbines were monitored have an annual average wind speed of over 5m/s, considered the lower limit of commercial viability.

The BWEA said that the national wind speed database (NOABL), a UK-government web-tool often used to predict on-site wind resource, can systematically overstate wind speeds in urban areas by 40 to 75 per cent. This potentially exaggerates turbine output by a factor of eight or more if used simplistically.

Even though Britain is the windiest country in Europe, care must be taken when positioning equipment, said the BWEA.

Alex Murley, BWEA small systems manager said: "Over the last three years BWEA has developed robust industry standards for both products and installers, to better educate would-be consumers on what the technology can achieve, if sited and installed correctly. The overwhelming majority of small wind system installations are a success. When they are sited properly they save money and energy. The Warwick trials do not show that small wind is not viable. We know that it is, and the experience of thousands of UK users bears this out."

He said that the UK leads the world in the manufacture of micro and small-wind turbines, exporting 40 per cent of product to over 100 countries.

BWEA called on the government to support further growth of the sector by urgently addressing the planning system which is preventing thousands of UK households and businesses from generating their own clean green energy.