Hardly, they're reading DC not AC, the ballast will induce a few milliwatts (at the max) in the wires and at 50~60HZ this will likely be within the margin of er

Hardly, they're reading DC not AC, the ballast will induce a few milliwatts (at the max) in the wires and at 50~60HZ this will likely be within the margin of error on a hand-built solar panel anyway. (Ed: The electrical meter likely wouldn't detect the interference as AC is generally self-cancelling interference on a DC line, unless diodes are in use) Induction between two wires is exceptionally low. Unless the two copper wires share the same ferrite core, you'll get diddly squat out. Noise in an electrical signal, is very different from noise in power, which would require an actual imbalance in the AC outputs, IE a power plant running at 50HZ and one running at 55HZ will produce a very unstable power supply.