Rain-powered generator makes 60-volt signals for smart drainage without batteries

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This sounds pretty neat! I know its made as a inclosed system in this instance!
But I was thinking, wouldn't it be possible to create this on a smaller scale?

I am an Electrician Apprentice, so I will 100% start to tinker with stuff like this when I get my own place, I don't have the space or knownledge for things like this yet :D

My English might not be good enough to explain my thoughts but lets try.

So many people have a water-collection system in their garden, so they always have water to water their garden or some have it so they can purify it for drinking water.

Now if this collection system was made out of the same stuff as the article talks about, we could also use that system to generate small amounts of power for smaller applications such as outdoors lights, a heating element if we attacted a battery or make the purification system run inclosed.

If we don't want to collect the water, we could funnel it through a pipe which would push the water into a waterwheel which would generation additional energy. This would properly need a certain amount of water-pressure before it could move the waterwheel enough to generate any energy.
But thats all something one can tinker with, this should work in theory.

For me its not so I can generate all of my own power free or cheaply. But getting "passive" energy for smaller application would be fun to fuck around with and it would also decrease my energy bill, but properly not alot.