....."The inaccurate readings are attributed to the energy meter's design, together with the increasing use of modern (often energy-efficient) switching devices. Here, the electricity being consumed no longer has a perfect waveform, instead it acquires an erratic pattern. The designers of modern energy meters have not made sufficient allowance for switching devices of this kind. When they dismantled the energy meters tested, the researchers found that the ones associated with excessively high readings contained a 'Rogowski Coil' while those associated with excessively low readings contained a 'Hall Sensor'."
I smell lawsuits since the PoCo's have been removing the old meters en mass....