Power factor correction device for home

[sonicmojo]

A buddy of mine is thinking of getting a part time job selling these devices to residential consumers but is wary since there seem to be quite a few opinions out there about them. I never heard of this before today and I figured this group of electrical gurus might have some knowledge. Does anyone have an opinion on whether one of these devices could actually help lower your residential power bill? Is it worth it considering the device is probably $500+ to get.

[ToneMerc]

I've only seem them in commercial applications. FWIW, I found this,

http://www.nlcpr.com/Deceptions1.php

TM

[paulster]

Does anyone have an opinion on whether one of these devices could actually help lower your residential power bill?

It can only help your bill if your meter records kVAh rather than kWh.

Traditionally billing has been done in kilowatt-hours, which aren't affected by your power factor. If you are billed in kilo-volt-amp-hours then your power factor will be reflected in your bill.

The question then comes, how far from 1 is your power factor, and how much are you charged per year for your electricity, so what is the cost of your sub-optimal power factor? Then you can work out your return on investment.

I'm billed in kWh so there's no incentive for me whatsoever to do anything about my power factor as it would simply be a cost to me in order to save the utility company some money but your situation may be different.

[Structo]

I bought one of those Power Saver boxes a few years back.

I basically knew it was too good to be true but I also figured it had big honking caps in it and could serve as a whole house surge protector.

So yeah, don't think it will save any energy, just evens out the surges.

It is a scam.

[paulster]

Some utility companies have got wise and are charging by the kVAh these days, so if that applies to you then it could maybe be worthwhile. It all depends how bad your overall power factor is.

The worst offenders used to be switched-mode power supplies but higher power devices (flat screens and computer PSUs) have to use power factor correction internally anyway so the only things you'll get a significant difference from will be conventional reactive loads, like fridges and air conditioning compressors, and dimmers if you use them on a large amount of incandescent lighting.

[sonicmojo]

Thanks for the responses! Lots of conflicting information out there on this topic but I trust this group. I just got a new digital meter on my house a few years ago but it is still kWH.

[paulster]

In that case you've got no incentive to change, unless you want to spend money for likely no gain!

[sonicmojo]

I move to Hawaii this summer where electricity is really steep. If my meter is kWah and once I look at my first power bill, I may think about it. It sounds in some ways like it acts kind of like the big filter caps in an amp which is why I brought it up here.

[passfan]

Power factor is the difference between apparent voltage and current and actual voltage and current. We can measure voltage and current and by multiplying the two determine the wattage. This implies that voltage and current are traveling in a perfect phase relationship ( voltage and current peaking at the same time). In real life this rarely happens due to inductance and capacitance causing one to lead or lag the other. It's this lead or lag that causes wattage to drop deceptively , and losses to occur which this device attempt to correct.