I've been on a mission with this stuff for a couple of months ,with the intention of getting my parents off the grid for their retirement.
Micro hydro @ low head is an untapped resource especially when its run of the river the less damming and channeling the better.
This guy is awesome for the water wheel potential he's got calculators on the page.
http://www.waterwheelplace.com/main.html
This is an expensive unit at nearly ten grand but its a good example of what is hard to find on the net as far as functioning run of the river generators.
https://www.altestore.com/store/wind-turbines-river-turbines/river-turbines/idenergie-river-turbine-p40461/
