PV Clamp Meter - Parasitic Inductance/Power consumption/other effects?

[bytemaster0]

Hello all,

A quick, but maybe not so quick question. I'm thinking of installing a home energy monitor to go along with my PV setup that's been recently expanded. Almost all of the units out there use clamp-style meters for the PV AC output. I know they're not the most accurate, particularly the split-transformer clamps, but I have a question for which I can't seem to find an answer: There's no such thing as free energy, so what effect do the clamp transformer coils have on the power coming from the inverters to the power panel, if there are current clamps on them? Clearly, some energy is being harvested in the form of EMF inducing a voltage in the transformer coil, but this must cause a teeny tiny bit of energy loss from the power lines, no? I realize it may be small, but my engineering mind won't let me rest about it until I put an order of magnitude on it. So, how much do you think it parasitically consumes? Milliwatts? Microwatts? Femtowatts? I realize that the meter itself is powered from mains power, I'm just interested in the potential power loss from an induction coil around the AC wires. Would love to hear anyone's thoughts. Thanks!

[NiHaoMike]

Looking at a 100A sensor I have, it outputs 100mA full scale into a 10 ohm termination resistance. That's 0.1W, while the 100A AC circuit will be 24kW at 240V. Basically it's lost in the noise.

[bytemaster0]

Excellent real-world response, I think I have my order of magnitude now and can sleep. The meter consumes more power from mains than the clamp ever will in this case. Thank you!