Micro hydroelectric power plant
Just like on a large scale, water power can also be used on a small scale to generate electrical energy. Provided the flowing water flows constantly, a small hydroelectric power station supplies constant electricity to charge small consumers such as smartphones, cell phones, radios and the like. In general, care must be taken with brooks that there is no gush operation there. If locks are opened somewhere upstream, a trickle can suddenly turn into a raging brook!
Many alpine huts in the Alps use their own hydropower plants with an output of a few hundred watts to a few kilowatts - in the time when these are managed.
Years ago I made a little hydropower plant for a tap that works to satisfaction. This means that the water pressure and flow rate of a conventional tap are sufficient to charge a smartphone, for example.