Exactly why basically that is my goal :)
I’m technically too urban to be entirely off-grid, legally, but I see no reason I can’t minimize my draw with a separate breaker system. Whole place needs to be rewired anyway because it’s ancient. Knot and tube ancient.
But most people aren't willing to go through that, and I cant blame them because there aren't any incentives to doing so, and most people don't realize how much cheaper used solar farm panels are, so it just seems like a really bad deal. And for most, who would have it installed for them, new, maybe thats true. Used with mostly-self-install is much cheaper. Even better if the whole deal needs to be re-wired anyway.
Solar water heaters definitely have the capacity to boil water, if they are made right (use a high temp transfer fluid, vacuum-insulated tubes, proper solar condensers, etc). It’d be difficult to get them to do it on a small scale without a heat pump of some sort in the mix, but even inefficient solar water heater setups need to be installed with a regular water heater after them mostly to down-regulate the temp as they get far far far too hot for practical use directly.
The greenhouse barrels are just for passive radiant heating, but if you use enough of them in the proper places, and insulate well, you can use them to make a passively-heated greenhouse that doesn't freeze at all, even up in the frigid northern climates (Canada, midwest US, Siberia, etc.)