At the turn of the century when ENRON was still around and ripping California off for power along with providing brown outs / black outs, I was building a new home. I didn't want to be held hostage by the power gods in Ca and elsewhere so I looked into a whole house generator rather than just a standby auxiliary unit.
The fuel source I settled in on was natural gas and the power generating capability was somewhere around 50KW and it was powered by a water cooled V8 natural gas engine. The price was not cheap as I recall it was just under $19K. Here is a link to a modern Honeywell equivalent that is about $16K, click here =>
48KW Whole House Generator.
These are significant pieces of machinery and will require a robust cement pad and periodic usage and maintenance to keep them ready for an emergency. You will need a 200 amp switch and you should get a switch and generator package that auto starts when the power fails.
This type of setup will power your entire house as if there were no power outage. With the increased dependency we have on cell phones and internet today this sort of failsafe provides both full house power especially important for things like refrigerator and freezer operation, A/C operation, internet access, phone charging and TV operation.
The additional cost above that of a $10K alternative and the continuous whole house power capability makes looking at the little stuff a waste of time.
Ed