I'm still waffling on this for myself. I don't care about the enviro part, but I have been looking at the solar + batteries option both for the current tax credits/deductions, and the zombie apocalypse part of my brain likes it as the best very long-term power outage solution.
On the other hand, I've also been looking at the whole house propane genset, and also propane genset + batteries options. The genset alone would be WAY less than the full solar system I'm looking at, even if I buy a second 300gal or whatever propane tank to dedicate just to it, and it would likely give me weeks of power before the propane ran dry. The genset plus batteries would be significantly more than just the genset, but still a good deal less than solar, and I think there are still tax credits just for whole house batteries.
I've also seen on youtube where guys have bought the batteries, running only them and charging via grid power, which seems to work great for automated switchovers for short outages. Then if the power goes out for an extended period, they built portable solar arrays. Basically like 5-6 400 watt panels on a portable 2x4 frame with a tilt function, and they roll that out to charge the batteries if they're looking at long term outages. It basically plugs into the same port that would be used for a dedicated rooftop or whatever solar array. Longish charging times compared to a dedicated 20-30 panel solar system, obviously, but kind of a neat SHTF workaround. And if they have a portable generator, they can always run that to charge the batteries up if the sun isn't cooperating.
One of the main reasons I'm looking at these options is to not deal with my current portable generator/lockout switch solution. Power outages here have been short enough that it's not worth me dragging out the genny and doing all the power switchovers, but sometimes I get annoyed if they go into the 4-5 hour range and I'm dealing with USB lighting, having to go to hotspot internet, etc. The current portable is a cheap and viable solution, but a dedicated and automated switchover system would be a major convenience.