On Thursday, 31 October 2019 10:56:12 UTC, John Rumm wrote:
On 31/10/2019 09:59, Brian Gaff (Sofa) wrote:

Yes one issue that has come up though is the method used to measure the
power used. Gass is pretty easy since it relies on flow,

Gas also varies in energy content, so knowing the volume metered is not
quite enough information to work out what to bill for. Hence the
conversion fiddle factors included in your gas bill.

but Electricity can
be influenced by the phase of the current draw in the AC voltage waveform,
and there have been questions before on what is the most accurate way to
deal with this aspect.

Domestic meters have historically been quite good at measuring only the
instantaneous real power transfer, and ignoring reactive currents. How
good they are with with modern loads with poor power factors caused by
high harmonic content (like many small SMPSUs) rather than a more
traditional phase shift is perhaps a more interesting question.

KWh, KVa and KVar meters (Spinning disk) are/were available.