[wagonman76]

15 HP 480 volt 3 phase motor. You could most likely get a single phase motor for it, itd not be quite as efficient but might offset the cost of getting 3 phase power installed at home. Or maybe run it off a lawn tractor engine instead.

Anyway 15 HP is 11.1855 kw. Say a common electric motor is running at 85% efficiency, thats 13.16 kw, the rest is waste heat. Dont know how long it would take to fill the tank, but just say it took an hour, then thatd be 13.16 kwh. At least here, electricity is about 10c per kwh, so itd cost $1.32 to run the compressor for an hour.