The Savonius or S-rotor windmill was introduced to the United States in 1924. The powershaft is located in the vertical plane rather than horizontally as in the traditional bladed Stuart windmill. This has several benefits. The windmill does not need a wind direction seeking vane since it doesn't matter from which direction the wind is blowing. Also, power is available at the base of the mill rather than at the top of the tower. The Savonius mill is also less easily damaged by high winds than the traditional windmill.
Iowa Science Teachers Journal
© Copyright 1979 by the Iowa Academy of Science
Hoffman, William G.
"A Classroom Savonius Windmill,"
Iowa Science Teachers Journal: Vol. 16:
1, Article 17.
Available at: https://scholarworks.uni.edu/istj/vol16/iss1/17