Well, you have good info.
- feet = 3 meters
- liter/sec with 1/3 stream, is that the maximum you can use or can you use all ?.
- l/minute = 2.5 l/sec
The power per liter/sec will be:
3 meter * 6 = 18 watts for each liter/second available
Since he has GRID power, the idea would be to have a small turgo turbine driving a induction motor at higher RPM than the slip and connect it to the GRID for energy credit ( so small that nobody will notice it but will "reduce" the expenses in electrical energy).
Ideally get a 4 poles small induction motor 1/3 or 1/2 HP SIZE
A Turgo, from www.h-hydro.com may be adaptable, though the head of meters is low --
I have 2 friends doing exactly that, one produces about 200 watts and the other 500 to 800 watts -- Guerrilla Energy Fighters --.
The good thing is that if the grid goes dead the generator goes dead and disconnects and the 500 watts unit gets immediate connection to a capacitor to produce local energy.
Nando