I have purchased a Ametek 20VDC Permanent Magnet Motor for use in a Wind Generator. I am thinking about using a Savonius blade design. The question I have is, with an aspect ratio of 2 to 1 I would like to build 2' wide by 4' high units, how many of these would I need to run this motor/generator in a moderate wind speed environment. Thank you for your information and help.