Disclaimer: I am purposefully avoiding the mathematics of this theorem when posing my question.
I understand that Poynting's theorem is basically the work-energy theorem of electromagnetics, and I understand how it's derived, but I'm having difficulty wrapping my mind around the intuition.
The theorem is usually expressed in the following terms: "The amount of work done per unit time on charges by the electromagnetic force is equal to the decrease in energy stored in the magnetic and electric fields in some charge and current configuration within some volume, minus the amount of energy that flows out through a surface bounding the volume" My confusion lies in the latter half of the explanation...the bit about electromagnetic energy flowing out through the surface.
This refers only to electromagnetic radiation, does it not? I realize the Poynting vector can be applied to any magnetostatic configuration to describe the direction of the flow of power, but lets say for the example of a current carrying loop of wire (for simplicity lets pretend its a superconducting wire and no energy is being lost to any sort of internal resistance and the circuit bears no load) , where the net flux of the E and B fields through the surface are zero, this cannot possibly transport energy out of the bounding surface, can it?