Recall I've been trying to figure out how to use my Leaf as house backup, using the OP's approach; problem is, the well pump, which runs at 240vac and has enormous startup surges. I've investigated two new approaches:
1. Given the high cost of 240vac-output inverters (the cheapest one that looks suitable is almost $1K), I've thought of replacing my well pump with a 120vac one. This seems totally feasible, simply at the cost of heavier wire, probably 10awg for my situation. Something like: https://www.waterpumpsdirect.com/FloTec ... 72430.html
. One helpful guy I talked to opined that using a 3-wire pump (with a separate above-ground control box is "easier" on whatever inverter I use. But he said the pump I need (0.5HP, 7gpm) is still recommended to be used with a 2kw generator-set. He was not enthusiastic about running it off the Leaf. (Wish I could talk to someone who had done so). There's also the expense of replacing my perfectly good 26 year-old pump; that is getting pretty long in the tooth, but OTOH I've heard that new pumps just ain't built like the old ones. Anyhow, when the old one dies, I'm probably going to replace it with some 120vac one.
2. Another approach has the advantage of being cheap, and safe (as far as damage to the Leaf or to my main pump). That is to get one of these narrow-diameter 12v pumps (https://www.envisupply.com/pumps/12volt.htm
see "standard PVC pumps" like the Tornado). Because the diameter is so small (1.82") I should be able to fit it down the 6" pipe beside the pipe (maybe 1.5" diameter) of the existing 240vac pump. Such a pump has very low flow (maybe 1-2gpm depending upon which one I pick and how deep I set it). But it's still a source of backup drinking water. One could even imagine using it to keep a small water tower (a big tank set up 8ft or so off the ground) filled. Of course, a little arithmetic tells you that you'd need a water tower about 100ft tall to produce the 50psi or so necessary to pressurize the house's water system, so that's probably a non-starter.