Turbine plans

[Bob B.]

I found this site and I am attempting to use a RC jet boat aluminum assembly as a water driven generator system. I live in Idaho and built an off grid cabin. I have a spring uphill of my cabin and have about 80 watts of constant water flow. I tried a plastic turbine to charge the batteries of the cabin but it breaks. So I am thinking of buying a jet pump assembly and running the water backwards through it with a valve to throttle the flow. Can a brushless motor work as a generator with a rectifier circuit and or can i use a motorcycle alternator? Do i need to reverse the impeller? How can i optimize the system for efficiency and what data parameters do i need?
i realize this is a little off subject but im looking for experts with experiance. Thanks

[larryrose11]

Unless you want to dive into recreational 3d flow simulation, I would suggest buying an off the shelf system where the engineering has been done for you.
Alternators have bad efficiency (50% or so) and are optimized for low cost manufacturing, not efficiency.