Things I've noticed. Even high efficiency residential fridges aren't that efficient. Some off grid ones use three times less power. And lot of the modern fridges have inverters to drive the compressor. Which means would not that big a stretch to add a 12/24V input like my portable fridge.

I mention this because not all household loads are the same. You really don't want your fridge to stop working. You probably can manage if you can't run you whole house air conditioner full tilt.

Having appliances that can run off back up and ones that can adjust their load probably would help.

Another random opinion is a lot of house wiring could be replaced with Power of Ethernet. There is a new automotive standard that provides up to 100W. A house where lights and light loads were run off POE could be trivially backed up by a battery.

And one ethernet cable per two bulbs would work fine for lots of lighting situations anyway.

But then that highlights the problem with trying to PoE and entire house - You have to run a line out from a PoE source to each item you want to deliver power to, and provide a port for each which comes at some cost. I guess you could try and run some kind of PoE passthrough circuit arrangement like you see with some office voip phones...

Complicated.

The other thing is price out Ethernet cable by the foot and compare with 14g Romex. The former is $0.05/ft vs $0.20/ft. And you don't need a licensed electrician to run it.

Also PEO is low voltage and power limited, so safer.

I gotta imagine 100W PoE requires some bigger cables than plain-jane Cat5E or even Cat6, though...?

The higher power levels require that you take into account how each cable is going to safely dissipate a couple watts, which is easy if you're not running big bundles.