Why won't power utility company charge for kVA instead of kW

Click For Summary

Discussion Overview

The discussion revolves around why power utility companies charge residential customers based on kilowatts (kW) rather than kilovolt-amperes (kVA) or reactive power (VARs). Participants explore the implications of this billing practice, questioning the rationale behind it and considering the technical aspects of power factor and its effects on electricity consumption and costs.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • Some participants suggest that charging for kVA would make more sense, as it accounts for both active and reactive power, potentially leading to higher charges for households with poor power factors.
  • Others argue that reactive power (VARs) is not charged because it is inexpensive to produce and primarily affects equipment sizing rather than actual energy consumption.
  • A participant questions whether the cost of infrastructure, such as wire sizing due to inductive loads, justifies charging for reactive power.
  • Some mention that commercial rates often include penalties for poor power factor, while residential billing does not typically account for this due to the complexity and cost of metering.
  • One participant uses an analogy comparing reactive power to a wooden box used for weighing lobsters, suggesting that while necessary, it does not directly contribute to the value received by customers.
  • Another participant notes that large-scale industries often manage their own power factor correction, indicating a different approach to billing in industrial contexts.
  • Some express that the tradition of billing only for kW stems from historical practices and societal norms, suggesting that it may not reflect current technical realities.
  • There is mention of legal restrictions that prevent residential customers from being billed for VARs, while industrial customers can incur charges for reactive power.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the appropriateness of charging for kVA or VARs in residential billing. Multiple competing views remain regarding the rationale behind current billing practices and the implications of reactive power on utility costs.

Contextual Notes

Some participants highlight the limitations of residential billing practices, including the lack of incentive to meter reactive power and the historical context of utility pricing. There are also unresolved questions about the efficiency and losses associated with high reactive power demand in residential settings.

  • #31
DrClaude said:
In my part of the world, CFLs have basically disappeared to the profit of LEDs. I don't think this is due to CFL myths, but rather to consumer economics.
Agreed. My perception was the CFL myths (and a few legitimte concerns) slowed their replacement of Incs.
NTL2009 said:
Agreed. LEDs have a lot of advantages over CFLs, and now that the cost has come down on LEDs, the market is speaking.
Er...could you tell me what they are, because they have been a problem for me. In particular, the economic benefit of CFLs over Incs was huge, but the economic benefit of LEDs over CFLs is essentially nonexistent.
 
Engineering news on Phys.org
  • #32
russ_watters said:
...
Er...could you tell me what they are, because they have been a problem for me. In particular, the economic benefit of CFLs over Incs was huge, but the economic benefit of LEDs over CFLs is essentially nonexistent.

Well, prices are all over the map for LEDs, I've got some on sale pretty cheap, no burn out yet, just a few bucks for dimmable, IIRC. I don't plan on buying another CFL in my lifetime, and I just bought some LED tubes to replace the flickering, buzzing tubes in my workshop. Probably no economic justification, the lights aren't on all that much, and the tubes are $17, but I get great light, and no buzz/flicker.

But I do feel LED often have advantages in quality of light, and no glass to break, no mercury fumes to worry about (and before anyone goes off on this, even though CFLs have small amounts of mercury, the form in CFLs, a kind of dust, is far more hazardous than liquid mercury), no start up issues. I like LED far more than CFL, and will pay a little extra for it. For most places where the light isn't on much, I stick with cheap filament bulbs if they provide the kind of light I need.
 
  • Like
Likes   Reactions: dlgoff, jim hardy and russ_watters
  • #33
NTL2009 said:
For most places where the light isn't on much, I stick with cheap filament bulbs if they provide the kind of light I need.

I really dislike unnecessary complexity.
To replace simple filament lamp with one that requires
a pre-regulator for power factor correction and a switchmode power supply with active current regulation ,
both mounted in the base where they get heat-soaked in most ceiling fixtures so give a short service life
and exhibit aggravating time delay between getting switched on and illuminating the room
and catch fire if you use them with a dimmer
is irrational
especially in moderate climates where you need heat so much of the year.

I did find the dimmable warm white LED bulbs quite suitable for reading lamps . Whenever i find one in a thrift shop for less than a buck i buy it.

Can't beat my 200 watt Incandescent for the carport, though

old jim
 
  • #34
DrClaude said:
In my part of the world, CFLs have basically disappeared to the profit of LEDs. I don't think this is due to CFL myths, but rather to consumer economics.
That's got to be right. All the "bulbs" that were available were the LED ones. I've yet to purchase one though. Guess I will now. :oldbiggrin:
 
  • #35
jim hardy said:
To replace simple filament lamp with one that requires
a pre-regulator for power factor correction and a switchmode power supply with active current regulation ,
both mounted in the base where they get heat-soaked in most ceiling fixtures so give a short service life
and exhibit aggravating time delay between getting switched on and illuminating the room
and catch fire if you use them with a dimmer
is irrational
When the CFLs first came out, I wondered about all the rare Earth's that would be used. I just now did a Google search on "rare Earth's in cfl" and this consumer report was at the top of the list. Hell, I need to get out more. That report was from 2011. :redface:
 
  • Like
Likes   Reactions: jim hardy
  • #36
From Don's link:

We found that CFLs could pay for themselves in less than a year, saving you about $52 per 60-watt incandescent equivalent over the life of the bulb.

I like to check such claims.

$52 at 14 cents/kwh is 371.43 kwh which a 60 watt lamp will consume in about 6190.5 hours.
A CFL drawing 15 watts over that same 6190.5 hours will consume just 92.8 kwh, costing $13.00

So the saving in energy cost is about (52 -13 )$ / (6190.5) hours = 0.630 cents per hour (that's to three decimal places, $ 6.299976E-3)
that's a dollar every 1/0.00630 =158.8 hours = 6.62 days
To make $52 would be 52 X 6.62 = 344 days not quite a year.
So we might as well round off that energy saving number to a dollar a week if it's on continuously like my kitchen light .
Hmmm first time I've ever done this arithmetic.

They'll last a lot longer than a year if power isn't cycled often and the electronics in the base stays cool.
My kitchen light stays on continuously and the bulb mounts upright not base up like a ceiling fixture, so heat rises away from its base.. And since it's always on i don't suffer that aggravating initial dimness.
First CFL there lasted seven years so i made out like a bandit on it.
Second one lasted just a couple months
Third one i think three years, memory is growing dim
Fourth is in about year four now.

So even a curmudgeon like me has to admit
CFL's do have that one redeeming feature. I guess ...

old jim
 
Last edited:
  • Like
Likes   Reactions: dlgoff and DrClaude

Similar threads

  • · Replies 22 ·
Replies
22
Views
10K
  • · Replies 11 ·
Replies
11
Views
2K
Replies
18
Views
2K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 23 ·
Replies
23
Views
11K
  • · Replies 8 ·
Replies
8
Views
3K
Replies
35
Views
8K
Replies
16
Views
6K
  • · Replies 16 ·
Replies
16
Views
5K
  • · Replies 7 ·
Replies
7
Views
2K