According to relativity,nothing can break light barrier.But a recent preprint on arXiv is to show energy transmission of commercial electric power(f=60Hz) is faster than light.(It is not the drift velocity of electrons because energy transport depends on the electromagnetic field instead of charged particles). Moreover, the speed increases as its frequency decreases so the value is infinity for a direct current(f=o).That is action at a distance(instantaneous interaction)!

My question is whether it is possible to design a circuit to compare this speed with c in lab? I'm interested to the experiment because it is of substantial significance to measure the speed of electric power for electrical engineering not matter the result can exceed c or not.