Generators

Good questions. I know others will have ideas. 

For the size of generator add up the maximum wattages of all the appliances you want to be able to use at the same time + some reserve.

Be aware that ac and refrigerators are heavy users. (we do not have them on our backup)

Try to hookup the generator only to the groups that feed those appliances so you dont have to manually switch off appliances you don't want backup power for.

Thank you Papito, from your experience and from what I've read is a 8000 watt generator large enough to    get through disruptions? Also, you mention manually switching off appliances you don't need on the system, does this mean unplugging them or just not trying turn them on?

I do not have experience with a generator (we use an inverter with batteries) but electric usage is a universal given. I guess 8000 watt is plenty. I just hope someone chimes in with info of types of generators here and their use.

Some appliances like Tv's and chargers use marginal current on standby but it wont matter much, maybe a few watts. No need to unplug them.

refrigerator, AC  and maybe a few lights. What would be the minimum size we would need,    -@Mmr986

That much is a technical question.

Around 400w per AC unit, then whatever it says on the fridge.

Assuming you have LED lights, not enough to bother calculating unless you are running around like a cruise liner at Christmas.

Before I moved to a place with more reliable electricity, I was looking at a charger/inverter with a bunch of lead acid batteries.

That will do everything except the AC for a lot of hours.

The same will happily look after AC, but you need a bigger unit and a lot of batteries. That gets expensive.

For generators, look for at least 1,000 W and quiet. Cheaper ones will work, but they can be noisy.

The trick is to work out your power needs, double the number, then buy a gen with that maximum output.