Hacking my way through off-the-grid survival

Having a propane powered generator seems like the cheapest easy-button. You are already producing tons of co2 with unregulated burning of wood, it would actully benefit your environmental profile. While propane cannot be gathered in the woods, neither can dishwashers, water heaters, batterys or controllers.

I'm honestly suprised when I hear an off-gridder is even considering a dishwasher, which is replaced easily by another 10 minutes at the sink, uses no wattage, less water. Seems it would be a smaller sacrifice in the big picture than the other issues.

Also consider passive heat options. Painting one side of your home a dark color is shockingly effective, even moreso passive heat exchangers.

Find old car batteries, and learn to recondition them. They are a bit bulky, but can provide cheap amperage if you understand the concepts involved. Most just need a bit more water and acid, and a desulfation to hold a majority of their original capacity.

Maybe there is a typo in the power of the water heater, 15000wh (15 Kwh) seems way too much, a typical water heater (at least here in Italy) is 1.6 or 2 Kw (not Kwh btw).

In off grid situations are common "hybrid" water heaters, with either a plain enough solar serpentine or with a heat exchanger connected to the wooden stove.