I don't remember Asimov writing about that. Larry Niven, though, talked about the phenomenon at length, though. IIRC, the "energy sink" was a large mass floating in the ocean and tethered loosely - it surged up, down, or sideways to absorb the excess energy. It was in a story called Flash Crowd, I think.
It is within the realm of possibility that I, hrrm, had that wrong.
