Debunking KVAR units

I was at a seminar yesterday that had multiple vendors of various products setup around the outside. One was selling an "Energy Savings" device that hooks up to your electric panel and promises savings on your monthly bill that seem impossible. The first of these devices I believe was called a KVAR. The one at the seminar was a different manufacturer but the same device essentially. It's a capacitor that supposedly corrects the power factor in your home and thereby reduces your bill. Residential customers are not penalized for poor power factor but we are billed strictly on KW used. The demonstration setup by this vendor showed a small electric motor with a "kill-a-watt" meter hooked up to the load side. A second meter was then installed on a feed through the "device" and when switched on the amp load did infact drop.
Since yesterday I've done a good deal of reading in the web and my conclusion is the "devices" work only to increase the profits of the companies selling them. I would like to hear from the resident electrical experts on this forum about these units. In particular I would love to know what Yanche's opinion is of these cause I think electrical engineering is his field.

I agree with you. My BS detector goes off. Ten to twenty percent savings, why no tax credit? If it is so effective why are they not being made or marketed by the big guys like GE, Siemens, Schneider and others? Their own marketing suggests it only saves with motors, how much of your electric bill is from motor loads? I am no electrical engineer but common sense tells me something ain’t adding up.

If it sounds too good to be true.....

Must be made by the same company that sells these magnetic things that either attach to your fuel line on your car, or get dropped in your fuel tank on a bike .. and promise a huge increase in mileage.

Sort of like stuff you pour into your oil that's supposed to magically rebuild your engine (i.e., stop leaks, increase compression, stop blue smoke, etc.).

Best bet, just shut off everything that doesn't need to be on...get CLF's, unplug transformers, etc.....

coalkirk wrote:
Since yesterday I've done a good deal of reading in the web and my conclusion is the "devices" work only to increase the profits of the companies selling them. I would like to hear from the resident electrical experts on this forum about these units. In particular I would love to know what Yanche's opinion is of these cause I think electrical engineering is his field.

There is little understanding of power factor by the general public, the demo you saw was an example of an ideal case for savings. An electric motor that had it's power factor corrected to unity with an external capacitor. But most electrical loads are not so simple linear loads like a motor. Typically the current drawn is complex and certainly non-linear.

Quoting from http://en.wikipedia.org/wiki/Power_factor

Begin Quote:

"The power factor of an AC electric power system is defined as the ratio of the real power flowing to the load to the apparent power in the circuit,[1][2] and is a dimensionless number between 0 and 1 (frequently expressed as a percentage, e.g. 0.5 pf = 50% pf). Real power is the capacity of the circuit for performing work in a particular time. Apparent power is the product of the current and voltage of the circuit. Due to energy stored in the load and returned to the source, or due to a non-linear load that distorts the wave shape of the current drawn from the source, the apparent power will be greater than the real power."

End Quote

You really need to read the Wikipedia article to begin to have an understanding of what's going on. In a home the power factor measured at the service entrance will vary considerably, be non-linear, be non-predictable and would require active power electronics to correct to unity. But even if you had it so what? You don't get a lower electric cost for what is measured by your power meter. The power meter measures "real" power not the "non-work" power returned to the power company. So there would be no dollar savings. Perhaps the latest state of the art residential power meter does measure the power factor and could charge more or less based on the power factor. In Maryland it's not on the utility commissions approved residential "R" rate schedule.

Bottom line is unity power factor is a good thing. Good for the power company, good for the stability of your equipment, good for the county because it reduces the total amount of electric power that needs to be generated. But for electronic loads, like computers and TVs, it needs to be corrected by each device. The old wall wart transformers are especially bad. Collectively they consume lots of power. New energy efficiency standards will greatly improve them. But again your power meter doesn't measure the improvement.

Remember what P.T. Barnum said, "There's one born every minute."

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

Sums it up nicely.

Yanche understands, I do not. However, I have a friend that understands. For a "fun project" and under his direction, we bought proper capacitors and built home made power factor units for our homes. They cost about $65 each to make. We installed them and if our calculations are correct, and they need no repairs, they will pay for themselves in just under 12 years. After that, wooohooo! Pure profit baby! LOL So....how much did your place want for one? If it was $650, you'll be paid back in about 120 years.

You see, basically, they only work on electric motors, not lights, not TV's not computers.

Say Mr Herrick, just think how much longer your coal stoves will run on a KVAR. Stanley would be proud.

Freddy wrote:Yanche understands, I do not. However, I have a friend that understands. For a "fun project" and under his direction, we bought proper capacitors and built home made power factor units for our homes. They cost about $65 each to make. We installed them and if our calculations are correct, and they need no repairs, they will pay for themselves in just under 12 years. After that, wooohooo! Pure profit baby! LOL So....how much did your place want for one? If it was $650, you'll be paid back in about 120 years.

You see, basically, they only work on electric motors, not lights, not TV's not computers.

This guy wanted $350.00 for it instaled or he would sell just the unit for $250.00. I don't think he sold any.

I'm On Fire wrote:http://www.nlcpr.com/Deceptions1.php

Sums it up nicely.

This is a good link that explains the potential savings. It's pennies, might even be micro pennies. Just remember there are two kinds of power flowing in your electric circuit between your house and the power company power plant. Real power and the so called imaginary power. Your residential power meter only measures real power. When you put these power factor correction devices on your service entrance to correct the power factor to unity, you reduce ideally to zero the imaginary power. But your power meter doesn't measure imaginary power, it's an instrument that can only measure real power. So the load as measured by your power didn't change. Not quite true but for all practical purposes it didn't change. So you didn't save any money because the power meter still records the same real power used. This is a SCAM. The devices sold can be demoed to save the so called imaginary power, but it's not power your electric meter measures. Using the power factor correction devices helps the electric power utility but not you. Well it does help you indirectly by making the power grid more reliable. But it does not, can not save you money. Enough said.