Hmm, i will have to look into that some more, as it stands i get a max output of 2.7amps and i don't know at what rpm it's cutting in but i can reach 12V turning the shaft by hand/fingers. i made a few PVC sets of blades like many how-to's on the net, i made a 4 blade set out of 8" pvc pipe, each blade was 62" dia and 4.5" wide and the widest, also made a 2 blade all in one out of 12" pvc, 46" dia and 4.5" wide. i only set it up on the top of a ladder, just pointed into the wind, no pivot, about 20FT off the ground in a residential area, with no load i would get around 30V with the 4 blades and would get around 50V or so with the 2 blade. so for now i'm going to try it with the 2 blade set up, was thinking of adding to more blades to it but shorter yet not sure what it would do and have had the time to set it up and test in the wind again