Upon re-reading, my response is rude, sorry.
Someone mentioned a comparison to a windmill, and it would work about the same if it weren’t for the trash in the water. Consider however that a windmill has to be 200 feet in diameter to produce meaningful power. I don’t think the river is that deep.
Blunt maybe, but not all that rude. As I say, I'm as mechanically illiterate as the Slaughter woman, I just have the sense to realize it. I'm also quite averse to spending our money on stuff the private sector (as pointed out above) would if there were a chance of its being profitable.