At work we have a 3-phase 55cfm screw type compressor. It is not big enough for our big sandblaster we use on semi trailers. We have to rent a diesel tow-behind compressor when we use it. I have a pressure-pot type sandblaster at home. In order to run it I have to fire up my gas powered 25cfm air compressor. My 240v compressor only does around 11cfm and is fine for air tools, painting cars, etc but not the sand blaster. If you want to use a generator to run an electric compressor big enough to do that you are going to burn a TON of propane to run that thing! Most people who have a whole-home generator don't have it setup to run every single thing in their home. Usually you cover the big stuff like heat, water, sump pump, fridge/freezer and a little extra for a few small appliances. To run all that plus have any kind of a surplus you would be looking at a 25 or 30kw generator, minimum. $$$$$$$