I was interested in that aspect of the story when I clicked into it, but I'm not really disappointed that it wasn't covered. Turns out it wasn't really the point anyway.

That said, he could easily have a generator rigged up to supply power. A lot of RVs have on-board washers and dryers, so the technology is widely available. If I were going to do something like this, I'd try to find dryers that heated with propane both for efficiency and to limit the electrical draw on the generator.