Power Factor correction?

[Nigel]

Apologies for English.. my Portuguese isn't good enough for this technical subject.

I have residential premises in Portugal and a Daikin Air Source Heat Pump for hot water & underfloor heating. It has always seemed expensive to run so I thought I'd install an energy meter to monitor consumption.

I installed an efergy meter http://efergy.com/eu/energy-monitors/on ... ehub3phase

This highlighted the fact that the Daikin Heat Pump was apparently consuming around 500 Watts on standby! So, underfloor heating turned off, hot water turned off, no pump running it was showing a continual consumption of around 500W, 24 hours a day, 7 days a week.

I have an additional problem with an Ikea induction hob that apparently takes 150 Watts on standby. There is a known issue with this particular hob that the power factor on standby is very bad.

The power used as shown by the Efergy meter correlates with the charges made by EDP - extremely high!

EDP tell me that they charge for actual power used (KWh) not apparent power (KVA). But, if my understanding is correct the Efergy meter is showing KVA - so I suspect EDP actually are charging me for apparent power.

So, do EDP ignore poor power factor for residential premises?
Is 500W on standby the right figure for a heat pump, is it just poor power factor, is there another reason?

Any comments very welcome (even in Portuguese )

Many thanks

[nelmindo]

Apologies for English.. my Portuguese isn't good enough for this technical subject.

I have residential premises in Portugal and a Daikin Air Source Heat Pump for hot water & underfloor heating. It has always seemed expensive to run so I thought I'd install an energy meter to monitor consumption.

I installed an efergy meter http://efergy.com/eu/energy-monitors/on ... ehub3phase

This highlighted the fact that the Daikin Heat Pump was apparently consuming around 500 Watts on standby! So, underfloor heating turned off, hot water turned off, no pump running it was showing a continual consumption of around 500W, 24 hours a day, 7 days a week.

I have an additional problem with an Ikea induction hob that apparently takes 150 Watts on standby. There is a known issue with this particular hob that the power factor on standby is very bad.

The power used as shown by the Efergy meter correlates with the charges made by EDP - extremely high!

EDP tell me that they charge for actual power used (KWh) not apparent power (KVA). But, if my understanding is correct the Efergy meter is showing KVA - so I suspect EDP actually are charging me for apparent power.

So, do EDP ignore poor power factor for residential premises?
Is 500W on standby the right figure for a heat pump, is it just poor power factor, is there another reason?

Any comments very welcome (even in Portuguese )

Many thanks

Esses contadores de energia, usam uma tecnologia que não é 100% perfeita, logo pelo fato de que não medirem a tensão. Estimam que a tensão é constante e perfeitamente parametrizada...
Quando os sistemas têm um terrível fator de potencia, esses contadores induzem em erro o utilizador, porque a corrente que está a ser medida, está muito desfasada da tensão, mas não está a realizar trabalho. Como não é realizado trabalho, a EDP como disse e bem, não cobra. Só cobra energia activa (kWh) (trabalho) e no residencial não cobra energia reactiva (kVAr). A soma vectorial das duas, dá o kVA.

[luisilva78]

Esses contadores de energia, usam uma tecnologia que não é 100% perfeita, logo pelo fato de que não medirem a tensão. Estimam que a tensão é constante e perfeitamente parametrizada...
Quando os sistemas têm um terrível fator de potencia, esses contadores induzem em erro o utilizador, porque a corrente que está a ser medida, está muito desfasada da tensão, mas não está a realizar trabalho. Como não é realizado trabalho, a EDP como disse e bem, não cobra. Só cobra energia activa (kWh) (trabalho) e no residencial não cobra energia reactiva (kVAr). A soma vectorial das duas, dá o kVA.

Concordo com tudo, apenas tenho que fazer uma pequena correcção em relação às unidades usadas. Energia reactiva deve ser medida em kVArh e não em kVAr, certo?

[nelmindo]

Sim é verdade e o mesmo para a soma vectorial: kVAh

[Nigel]

Many thanks for the replies.

I understand what you're saying. The measurements from the Efergy meter is probably wrong because of the reactive component. From the 2 pieces of equipment (heat pump & kitchen hob) I'm seeing them register around 650W combined on standby...

But... the amount I'm being charged by EDP and the amount being calculated by the Efergy meter agree with each other.

My last bill for 59 days showed a consumption of 1226 kWh - the Efergy meter is showing about 20 kWh/day

This is a residential house with 2 people, no heating other than hot water (on the heat pump), no air conditioning. Electric cooking, a fridge & a freezer, TV and lighting.

I'm paying for an average consumption of 860W.... which just cannot be right. Take out the 650W & you get to a more realistic 210w.

I just don't understand why the high charges! Is it possible the EDP meter is set wrong and registering kVArh?