The wiring must meet code, but he could use a 5kw generator if he wanted to. It just wouldn't do much to power his house. Most houses would run on 15kw IF it put out 15kw all the time. No wind, no wattage. Then he has to have a backup diesel generator to run his toys. I can just imagine him running around checking his gauges to try to figure out what he has to turn off and what can be left on. The freezer is always the last doohickey to get cut. You have to have a generator to at least run that. I've lived in hurricane country my whole life. I know power problems. We also have to have air conditioning down here that takes at least a window unit in one bedroom. Most have at least a 5kw to run the fridge, a few lights, and a window unit in one room. After Rita, I had no power for 30 days. Try sleeping in 90 degree heat with 99% humidity, and cooking on a Coleman stove for 30 days. A generator and a window unit is a must in those conditions.
I'm just imagining this guy has a LARGE diesel generator with a 500 gallon tank siting outside, but you didn't see that mentioned in the "green" article.