something tells me the amount of electrical power generated by this system would be absolutely minuscule.

Why can't I have this at my house used with solar cells, wind turbines to make me partially energy independent?

Charcoal filter not required, you could achieve this: ""equal to or cleaner than the water in the network supply system of Mexico City," by passing it through a sock!!

Maybe the power generated per household is small but what about collectively city wide? I've always wondered why nobody has installed generators in toilets.
"Electricity generated by that turbine is used to charge 12-volt batteries, which can in turn be used to power LED lamps or other small household appliances."
You see, they make no suggestion it will power the house.

Miniscule power might be overcome by stacking a bunch of units, maybe. I wonder about junk in the incoming water. One leaf could do a number on a 1/2" pipe, much less a microturbine with its teeny blades. The flow rate will be governed by the charcoal filter below. The amount of electricity created will depend on rainfall, which peaks in Mexico City in July and is less than 5cm per month October to April. Similar generation projects using interior sanitary piping have already been proposed, so this is not an invention, rather an adaptation. It is an interesting project, but I don't see much future in it.

Adrien, it depends on how much rain volume your area experiences. I can see that this free source of energy would be a fantastic green upgrade to many homes and commercial buildings in Vancouver, for example. Further, buildings could have their rooftop drainage systems tailored to direct runoff to fewer and larger diameter down-pipes; thereby increasing flow to larger capacity turbines. The idea that filtered water could also be created is great but that's not our problem in a city whose North Shore mountains experience 110 inches of rain per year.

Install these micro generators in the water supply lines to every home, everywhere!

i can;t believe a simple photovoltaic wouldn;t
a. generate more energy and
b. be a lot cheaper per kw or kwh
wle

Power = Flow X Pressure ...or... Watts = Litres per Second X Vertical meters from the turbine to the surface of the water X gravity (use 9.81)
From a "low-income home" presumably single story and fairly small roof area, the power produced here would be tiny, but it might just counteract self-discharge of the battery.
Stacking them wouldn't work because the first one uses up all the pressure.
"Green" shouldn't be mentioned if you're using chemical storage. And thankfully they haven't mentioned 'green' themselves.
I have 10 micro hydro turbines, stacked, $14ea, from aliexpress. This is running my lights, usb outlets, fan, radio, bug zapper, (in-car) DVD player. No batteries, 24/7 free power, and super-green. Not everyone has a nearby waterfall though.
I also have a turbine connected to my toilet sistern that powers an exhaust fan as the sistern refills. Something everyone should have. Maybe these guys can adapt their product for this.

@ Steven A. Schnitzer Each turbine would use up pressure. So the city would have to drive the pumps harder, or there wouldn't be any water pressure at the end of the line.
This product would produce more energy if the downpipes acted like tanks, which would allow pressure build-up. Without pressure, flowing water has very little energy. Pressure only comes with altitude, not volume. Maybe run a pipe uphill to a neighbours gutter? Or to a communal rain collective roof on top of a nearby hill, with a pipe down to each household?... with a rain storage tank??... acting like a battery?? a non-chemical battery... now we're talkin'