vertical wind turbine based on sailing engineering principles. The turbine rotor is rotated by two spiral-formed vanes.

http://www.windside.com/products.html

Windside Products
WS turbines

The Windside Wind Turbine is a vertical wind turbine based on sailing engineering principles. The turbine rotor is rotated by two spiral-formed vanes. First tests were made in Southern Finland in both inland and marine environments. Laboratory wind tunnel tests were also made. For over twenty years Windside have continued to research, test and develop battery charging systems of varying size and class in conjunction with development of its own wind turbine toward larger and more efficient models.

Windside Wind Turbine models have differing construction. These differences are needed for use in different conditions. Differences are indicated by the letters A B or C at the end of each model number. These letters indicate what sort of conditions the model is designed to be used in.

For example A is for use in winds up to 60 m/s. B 40 m/s. C 30 m/s