December 30, 2008
By Paul Gipe
Britain’s Renewable Devices introduced its “Swift” micro turbine several years ago to criticism that its estimates of annual production were inflated. See Roof Top Over the Top in Britain. Since then the manufacturer has revised the claim of annual production on its web site.
In 2008 Western Michigan’s Cascade Engineering bought the licensing rights to the turbine in the US.
Cascade Engineering’s move into small wind turbines is one of several similar efforts in Western Michigan. See Windtronics 760 Estimated Generation.
Cascade claims on its web site that the Swift Mark II will generate 2,000 kWh/year.
Can it do so?
Yes, but at sites unlikely to be found in Michigan at heights where the turbine is likely to be installed.
The Swift is a 2.1 m diameter wind turbine that sweeps about 3.5 m². A wind turbine of this size requires an average annual wind speed of about 7 m/s at hub height to generate 2,000 kWh/year. Sites this windy are rare in Michigan, especially at the rooftop heights that this turbine is intended to be used.
