I don't have any expertise in this, but off the top of my head: - wind power would be tough because of sand in the wind. I imagine that would make the tech break down often. Guess it depends on what kind of desert you're talking about. - Bedouin/Saharan peoples are probably a good reference. They had/have cisterns throughout the desert to preserve water between rainfalls. I think they were largely nomadic but I don't know the motivation for that (trade vs food supply vs ?) - Bill Gates reports drinking water from human waste tastes fine, you could probably get your hands on the tech his people are developing.