Power factor and meters

[Kram]

Something hinted at in one of Bigclives old youtube videos, was that older meters will measure the actual power used. I think it was a video about a old meter dissasembly.

Newer smart meters will measure the current used and ignore the power factor?

This will make small non-ideal loads very expensive to run.

We have quite an old, 1970's build house and meter with no intention of upgrading. While I realise a low power factor is bad, but will it cost me?

My furnace has a well over powered element and with an SCR, gets a pitiful 0.3- 0.6 power factor. 3kw+ element but usually at 0.5-1.5kw to avoid thermal stresses or self destruction.

I can change the element for a lower power version, or add a PFC capacitor to try an jmprove things.

A capacitor is probably a good idea anyway. How do I work out what value uF to use?

 

[Seadog]

I think the new meters take power factor measurements and display kVAh rather than kWh.

 

[RaceDiagnostics]

New meters measure both VA and W, however all billing is done in W, I think there is legislation for this to be the case.

The law would need to be changed to allow the suppliers to bill you for VA.

So for the time being it's best to have a poor power factor as you effectively get free power.

 

[RaceDiagnostics]

Equipment manufacturers are being force to meet certain minimum of values these days to try to make them bill correct values. But a high of is bad for the consumer paying the bill.

 

[Chris Snow]

Domestic has always been kWh but commercial they can penalise you for a poor PF

 

[Matrixx]

kW is kVA *pF.
Business are charged for kVAr ( reactive power) I have put in generator controls systems in to run in parallel at very low power factors to correct the kVAr used.