Savonius 50 RPM

First try to exploit my time to make a savonius generator. It is a 5,5Kw 3 fase AC motor with neodimium magnets added to his axis, but is too much generator for a low power blades. The generator gives 15VAC and 60 amperes (900W) at 100 RPM, but the blades cannot get more than 50RPM with good wind and full charge, in this case, the generated power rounds 200W/h, that power is about 40% of the electrical consumption of my house (if we would have good wind 24 hours/day/month). I recommend to every people that