not nessasarily, still too little information to go on. You still haven't said what lights, how many, and any other equipt that might be going....don't know your "average" consumption, and I'm only assuming it's monthly as that's how mine work's....and your geographic location plays a part too.....in my location monthly swings are a common occurance so without other factors ( an exhaust vent sticking out a window) just a increase is not a factor in finding a grow anymore.