Originally Posted by KarTek

Something to consider: Are there any buried feeds to any of the out buildings? I have a buried feed to my shop and something underground failed and electricity started "leaking" out into the ground. A high enough resistance to draw a substantial amount of power and yet not enough to pop the 60 amp breaker. This resulted in a steady unexplained rise in the electric bill over about 6 months until I noticed the trend and found the problem.