Wishfull said:
I like the inverter idea. What batteries and solar set up would you need minor stuff like 12v lights and tv and a car fridge etc. ?
If you wanted something for just infrequent backup power a keystart gen is probable smarter and better bang for buck.
If you get repeated outages then a small off grid setup could be put in.
Millions of scenarios, if you are planning for outages over a few days then you'll need to charge the batteries too so solar panels or other dc charge source are required.
A gen with decent charger could also top them up and leave the inverter running at night when everyone wants some quiet(bit rude running a get at 9.30pm).
If the system is intended to be used for say 5 hours or so then you could just have an inverter hooked up to batteries and simply have it on a mains charger, when power goes off you rely on the battery bank, when the mains comes back on the batteries will get topped up again.
Sizing the inverter can be tricky as some appliances require huge start up power, 240 fridges are like this, when running they use relatively small amount.
For a tv car fridge and 12v lights then you would be looking at a small setup like many in 4wd's have. 1500w pure sine wave inverter and prob 200ah of batteries would be good.
Something to run 240v fridge would need a pretty big inverter and maybe 400ah+ of batteries, it entirely depends on how much the appliance/s draws and how long you want to run it.
Do the maths yourself or look at some calculators on the net like this
https://www.rjbatt.com.au/deep-cycle-battery-calculator/
Don't forget to allow for max of 50% draw down from the battery, so 200ah will only give you 100ah minus losses of usually 10% so you really only have 90ah max available if the battery is in good nick and fully charged.
@Meller, sounds like a ripper system, what inverter, battery bank, panel watts are you running?