Here's a picture of my test rig of a Savonius windmill. The rotor is mounted on the axel of a small DC motor. But this is not the right way to draw power from a Savonius because of the low speed of rotation. In fact the output voltage typically hovered below 1 volt, only reaching 1.5V during unusually strong gusts of wind. The motor needs to be geared up to high speed, or, better still, a custom-wound alternator is used as in the Picoturbine.
Regards
Joseph
http://www.instructables.com/id/EVM8ECZA4VEYKVV734/ (http://www.instructables.com/id/EVM8ECZA4VEYKVV734/)
Build a Savonius Wind Turbine or VAWT to make electricity
from instructables. this should be fun to do - if one has the funds to do it
An now you can try one this size for a bit more power ;)
(https://overunityarchives.com/proxy.php?request=http%3A%2F%2Fwww.packratworkshop.com%2Fpics%2Fturbines.jpg&hash=803aad8c39c5f578b294e741328a9aa9a1fb6c27)
@ all
I made one similar to this, try taking all 4 half sections of can or bottle or whatever you cut and putting them on the same plane, not two on top and two below, you will get much better acceleration with mabey a few mph wind and have constant juice but you need all 4 together on the same horozontal plane :)