Windmill
The Savonius Rotor: A Durable Low-Tech Approach to Wind Power
The Savonius rotor was originally designed by Finnish inventor Sigurd Savonius in 1922. It is classed as a drag-type device, and is understood to have relatively low efficiency but high reliability. Interest in the Savonius rotor and other types of Vertical-Axis Wind Turbines (VAWTs) became elevated during the oil embargo and resulting energy crisis. Also, during the 60s and 70s, the Savonius was considered as an example of appropriate technology for rural development in the third world due to its low maintenance requirements.