There have been several threads on the web over the years about how much electric power a shop uses. The easiest way to tell is to meter actual power usage. Hialeah Meter will sell you a refurbished power meter like the ones on the side of a house. You can pick up a meter base from either BORG, or electric supply house. My "Easy Read" meter cost less than $35 delivered. I'm using it for a well pump that will get it's power through the outside panel in my rental next door. Most years, we use about $18 worth of electric, but with garbage fees, pay over $360 per year. That amounts to a 2000% mark up, plus the $1.50 is a commercial rate, so actual cost under residential rates is less.