I hope necroposting isn't too frowned on here, but ...
This is the sort of thing that "keeps on giving," but in the wrong way - the idea is too easily misunderstood, and promoted by well-meaning people all over the Internet. I STILL see this (several "news" articles along with the Youtube video in #21) and similar stories on Lucid Energy (whether using the company's name or not) posted on Facebook, and the comments are NOT about whether gravity feed works to generate electric power (it obviously does, just like hydroelectric dams everywhere), but people DO NOT notice or understand the "gravity feed" part and think it should work in ANY city, regardless of the source of water. It's really the common interpretation of this thing that's become a scam.
This recent (four months ago) post on Upworthy is arguably part of the problem - it's one of probably many "feel good" places where this sort of thing gets posted online:
https://www.upworthy.com/portland-now-generates-electricity-from-turbines-installed-in-city-water-pipesThe only mention of how it actually works is about eight paragraphs into the story, near the end:
"Fast Company points out that, in order to be cost and energy effective, Portland’s new power generators must be installed in pipes where water flows downhill, without having to be pumped, as the energy necessary to pump the water would negate the subsequent energy gleaned."
There's no mention, stated or implied, of these pumps needing to be gravity fed up to this point. I doubt many of the people who post about this thing understand the concept even if they've read that far.
But wait, there's more - read (if you dare) the Youtube comments!
https://www.youtube.com/watch?time_continue=8&v=Vpubi1GjoBE