Hello @martin, just letting you know that @carolina_carvalho has come forward to write an entry about the ecology of Witness. Maybe the two of you could connect?
I think @yudhanjaya has more or less assumed that solar power is mature tech in Witness. We have several indications that this is so, with The Assembly basically growing out from an experiment (forced by a period of scarcity) of fully decentralized energy production. On the other hand, I imagine a floating city would be mostly flat – not many mountains and valleys for hydro power. But we can change this, of course, or maybe I am mistaken.