I am using a 100gal propane tank( filled to 80gal) for a 18 kw Generac.(works great, lost power for 6 hrs and hardly knew it) My delema is that my propane company will not let me have another tank because of my usage. Because of liability issues the propane company will only fill their tanks. I still need to figure propane gal per hr/day for the Generac. any thoughts or sugestions?