"Word I hear is that the real kicker will be solar powered extraction of atmospheric water. That could cut the number of transport convoys by a bit more than a third."

That wouldn't be that hard actually with the cool tubes (in computers)and chips found in 12v freezers. I may experiment around one day to try to collect the moisture using fans and heat exchangers to see if I can generate water. the only draw back to these systems is the humidity has to be higher, in the desert it's a little more harder. But that's a great idea and I'll look into that.