Well, I’m not alone (thanks Google 😦 ) but I think as an addition to a prepping person’s system it would add to the consistency of power. In general when it rains, there are clouds and the skies are dark. Not good solar power days. BUT there is a good side effect. Vertical kinetic energy of the falling rain (free energy) turned into rotational energy of a turbine. A small tank on the roof of a house already built to cache rainwater could turn the height difference of a house or garage into electricity. Not a lot. But certainly some is better than nothing!
Because the system generates electricity from something that is going to fall and expend the energy, it’s ‘free’ energy. Because it runs when things are dark, it doesn’t have to be super efficient, just close to maintenance free – sure I wouldn’t base my house on it (at least without having 10000’s of sq. ft. to store all the energy) but as a way of smoothing out the solar power bounce (7 days sunlight, 3 cloudy, 2 rain, 3 sunlight 4 cloudy, 1 rain…) and capturing something that we let fall to the ground, I think it’s worth more study, as a prepper. In general for real power generation, it should be used in a place where it rains more often than not. Will post my results.
Note – I did find these:
(note this one the young man doesn’t seem to understand that the resistance to movement needed to generate electricity would slow the flow of water from the water towers and the elder gentleman is asking how that would effect the flow of water to the recipients.)