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Talk:Article:Are U.S. CFL's Designed to Make Us Pay More on Our Power Bills?

Lasted edited by Andrew Munsey, updated on June 15, 2016 at 2:02 am.

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Discussion page for Article:Are U.S. CFL's Designed to Make Us Pay More on Our Power Bills?

Image:CFL bulb 95x95.jpg

In Europe, a small capacitor is added to Compact Fluorescent Lamps for power conditioning and additional savings on the utility bills. Similar savings can be realized on AC motors. Why are these inexpensive modifications omitted from U.S. CFLs and many residential motors?


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Consumer power meters measure "Real Power" -- they don't charge you for "Reactive Power" (VARS), so improving the power factor of devices will have negligible effect on your power bill. Improving the power factor does help the utility save some money though because poor power factor heats their transmission lines and transformers more. Utilities correct power factor at a neighborhood level with big capacitors on the power poles.

If consumers start correcting their own power factor there's a chance that would result in over correction because the utility is also correcting for the average power factor of the neighborhood.

Large industrial users do get billed for VARS with a separate power meter, but they can correct it with one big capacitor at their power panel.

A case can be made that modern switching power supplies that CFL's and PC's use could actually cause you to be billed for less power than you're actually using because of the pulsing nature of the current draw.

In any case, I think LED's will soon replace CFLs anyway, so it's a moot point.


Background information:

‘Real’ power is named thus because it is the ‘real’ part of total power when AC power is represented in vector notation. “Real’ power in kW is the integral over one complete AC cycle of the instantaneous values of amps and volts at each point of integration. Only that portion of the current which is in phase with the applied voltage ‘counts’ in the calculation of ‘real’ power.

The other part of the power that you actually use is the ‘imaginary’ part of the vector representation of power – that part of the power where the amps are not in phase with the applied voltage. The total load (kVA - thousands of volt-amperes) consists of the vector sum of the ‘real’ power (kW - kilowatts - thousands of watts) plus the kVAr (thousands of volt-amperes reactive).

If you read voltage across the AC line with a voltmeter the display is a value proportional to the peak voltage in the AC cycle. If you read amps through the AC line with an ammeter the display is proportional to the peak value of amps during the AC cycle. Multiply the two readings together and you have the kVA.

But note that each of these two meters have no way of knowing what the other meter is doing or when the peak occurs for the other meter. If the peaks are not in phase (that is if the power factor is not 1.0) then the kVA is not equal to the kW and your multiplied reading is not kW. To read kW on a reactive load (when the power factor is not equal to 1.0 you need a single meter which can perform the instantaneous multiplication of volts and amps and integrate those values over one complete cycle – a watt meter. This is how the Kill-a-cycle and other power factor meters work – they take a kVA reading and a kW reading and then compute power factor.

Websites of interest:

Landis & Gyr Meterman’s Handbook (may still be available from this meter manufacturer…)

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Comment reply by Author:

The area and city we live in determines how you are charged (..the policy of your specific utility company), and many American consumers are being charged by Apparent Power still. As the article points out, CFL's are a minor drop in the bucket compared to non-PF Corrected AC motors. But you are quite correct in that if you are being billed for Real Power by your meter already, then you would not see any savings for perfect PF .

Also, i believe that the cost factor of LED's will likely keep us on CFL's for several years to come... Long enough that convincing the industry to PF Correct them would be useful.

By the way: Just today i received a long-awaited email reply from "Energy Star" which states with certainty that they do not use Power Factor as a consideration for the Energy Star award (only took 3 weeks for the reply, lol.. But after all it was "vacation season" so perhaps they can be excused). Who knows maybe that will change this in the future if more people mention this to them... As frankly, this is an embarrassing disclosure for them.

I also recently found some CFL industry standards (from a industry cooperating promotional group)that list varying "quality tiers" for CFL's... And all of the 120VAC models including the most expensive tier, have a PF of less than .6 and most are in the .5 to .55 range.

Also, recently it has come to light as this issue with CFL's is looked at closer by people in the Open Source Energy Movement, that many actually have leading-current Capacitive phase shift causing the poor Power Factor (which is caused by the type of ballast used in the circuit design Magnetic or Electronic). So in these cases, inductance and not capacitance would be needed to balance. But it would appear that correcting the existing circuits of these units would be difficult so a total redesign of the circuit would likely be needed. But in these cases, since we have the European models to go by, the manufacturing cost of CFL's with good PF would still not be significantly higher in mass production once the design changes were made.

And since the writing of the article there have been further improvements with ~Imhotep~'s great "Radiant Oscillator Charger" circuit which provides a significant battery charging capability besides creating light, so the battery-powered system is even better with electronic switching and perhaps closer to being a closed-loop self-sustaining free energy device )

His new website is at (he just recently changed Hosts):

Thanks for your comment and interest!

Steve Windisch / Jibbguy 8-28-08

See Also

Directory:Compact Fluorescent

Directory:Compact Fluorescent Lighting (CFL) Downsides

Directory:Power Factor Correction

Directory:Steve Windisch

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No utility in the us uses a kvar meter to bill residences the watt/hour meter they use is based on volts x amps x power factor

correcting power factor (with capacitance) to 1 (from an avg. of .96, extremely bad for a residence,to .998) actually cost you more on your bill not less.Most utilities figure that into the rate for residences and penalize large industry or make them correct for poor pf.