Yes, I can think of another way to put energy into the system, without wires: inductance. Simple.
***There are good reasons why no one is putting forth this as a reasonable explanation. For one, the effect drastically reduces with distance, and for it to work across a meter it would generate tons of EMI and other measurable effects. Also, there would be coils in the Ecat when they opened it up.
How do you know there are no coils inside? Rossi didn’t allow inspection of the innermost part.. What about in the pipes adjacent to this “reactor” core? Just thinking out loud, but looks to me like there are plenty of places to hide things.