Found this awesome simple demonstration of Flettner rotors.[1] One question I have is, how would this work with a sort of semi-circle fan version, where the bl

Found this awesome simple demonstration of Flettner rotors.[1] One question I have is, how would this work with a sort of semi-circle fan version, where the blades retract when they start getting pushed into the wind. This could theoretically have the rotor turn off of just wind power instead of external power. Here's a crude drawing lol [2]. [1] https://www.youtube.com/watch?v=XsGin7CFaF8 https://www.youtube.com/watch?v=XsGin7CFaF8 [2] http://draw.to/D47BxHT http://draw.to/D47BxHT