My primary goal is reliable house power during an outage, ideally running at least one central ac unit, and PERHAPS running 3-ph machines during non-outage times [assuming I get the workshop built]. Spoke with an electrician working on a natural gas 15kw [40a/240v output] set across the street the other day. Said he would not put anything smaller than about 25 kw at his house, but he's thinking non-mil sets.
If you've got money to burn, 25kW would sure be nice.
But realistically, 15 kW should handle all your needs for a week or so of power outage.
If you want to run everything in the house just as if there were no power emergency, you'll probably need more. You'll have to start doing some calculating and measuring to find out just how much you need.
If your utility company uses smart meters, they may be able to tell you what your demand is by the hour.
Now, if you want to run that 50 foot combination anti-zombie electric fence, ICBM missile-destroying laser, and instant can opener, you shoulda bought one of those 2
MEGAWATT units that were sold by GL at Ft. Meade a week or two ago. They only went for about 5 grand each. Chicken feed!
I'm guessing it would take that much in
fuel to run one for a day!
(Am I going to get whacked for the zombie comment?)