The only problem I see with the pelton design is that it needs a fairly high head, on the order of a minimum of 15 meters or better. That might not be possible for all applications...

I suspect that what will happen is a at first we'd deploy pre-built PV solar arrays, then build smaller applications like that one in the pdf file [if only because it's easily shipped out.] like you said, followed by a home built larger central pelton design utilising local materials. [in the story there's this mothballed airfield complete with an aircraft boneyard.] The final step in the story version of course would be to expand the pre-existing geo-thermal steam turbines.

I like the idea of tying the septic and irrigation systems together though.