AC power

[Peabody]

I have a 120 VAC coffee mug warmer that's a capacitive dropper zener circuit powering an MCU which turns a relay on and off.  Even when the heating element is off, the zener circuit is always on.  My Killawatt meter says it's drawing .5 watt, 5.8 VA, with a power factor of .08.  What is my home's electric meter measuring as KWH that my bill is based on?  Is it the watts, the volt-amps, or something different?

[Ground_Loop]

Your meter indicates real energy usage by law. So KW-hrs.

[ksat44]

Most residential electric meters (in the US, anyway) only register real power, as Ground_Loop stated. Most energy used in the household has a decent power factor already, so utilities aren't that concerned about them (from my understanding, anyway). Larger businesses/factories, however, are often required to have meters which also record kVA and are charged extra if that amount exceeds the regular kW.

[CaptDon]

Your meter has both a voltage coil and current coils and reads the true watts consumed read as Kilowatt Hours or KWH. Factories with really bad power factors use capacitor banks which are sometimes automatically switched in or out to improve the power factor and reduce the excess current seen in inductive loads. The capacitor banks usually fail in a spectacular fashion and scare the shit out of anyone nearby!!!