1 You buy a solar panel to produce electricity
2 You buy a boiler to power a generator to produce electricity
3 You use the tap water to produce electricity
4 Buy nuclear power raw materials to produce electricity
5 Use gasoline and diesel to produce electricity electricity
6 Use natural gas to produce electricity.
7 Use dry batteries to produce electricity
8 Use biogas to produce electricity
In principle, there is no not much difference. They all rely on water to grow. the rotor must rotate to produce electricity. However, hydropower generally refers to the use of height differences in reservoir water levels to produce electricity, which requires larger devices. The tap water pipes are so thin et the installation is small. I'm afraid the difference between the two is not minimal in terms of technical details. As far as I know, hydroelectric technology is mature. If hydroelectric technology is used as a benchmark in producing electricity from tap water, it will at most be considered a practical new technology and not an invention.
And from the point of view of energy saving, the water pressure in the water pipe is obtained by human consumption of energy. Adding devices to the water line will definitely cause the water to lose some water pressure, meaning the water company's pressure. energy is lost. The ideal is to convert the water company's energy into your own electricity without loss, while sacrificing your own water pressure. There is neither an increase nor a saving in energy for society as a whole.