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Herm Williams
04-22-2010, 08:21 PM
I see many claims (ebay sellers) regarding savings on my power bills if I buy their units. Would it be worthwhile to install a unit on my home which has a 125 amp service panel? How would I determine the correct size? TIA

MaxHeadRoom
04-22-2010, 08:30 PM
You would need to have a power factor analysis done, usually only if you have a large number of inductive devices, motors etc, and even then the correction is only usefull if the system is self monitoring and switch in correction as needed.
In an industrial setting, harmonic distortion detection should also be done to be truly effective.
If this is a residential situation, it may not be worth the cost of equipment.
Many local service suppliers will carry out an analysis for free, but I am not sure about residential.
M.

flathead4
04-22-2010, 08:44 PM
Sounds fishy, to me. Like a magnet on your fuel line is supposed to give you better gas mileage. Do a google search and you will find numerous sellers saying how great they are, but check out the links below.

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

http://www.ecofactory.com/news/are-kvar-units-scam-091809

Tom

Weston Bye
04-22-2010, 08:46 PM
How big and how many are your motors? Ideally, the power factor correction capacitors should be sized to each motor, and used only when that motor is used. Could be expensive to outfit all motors.

If all motors are similar in horsepower, and you only use 1 at a time, all sharing a circuit with capacitors on a contactor that pulls in when any motor on that circuit comes on. Was it me and if I had to do this, I would design a load current sensor that pulled in the contactor. Also I would outfit the compressor with its own caps.

Before I did any of this though, I would calculate the expense and payback to see if it was worth doing.

JoeFin
04-22-2010, 08:52 PM
These things come and go with the slumps in the economy.

What is this guy's claim to fame "NASA Technology?", or "Secrets GE, Westinghouse, & the Federal Government don't want you to know?"

flathead4
04-22-2010, 08:56 PM
The units on eBay claim to save 30-40% on your electric bill and only cost $79. Sounds too good to be true, doesn't it?

Tom

Evan
04-22-2010, 08:58 PM
It won't be fishy for long. The power companies are changing over to digital meters than can measure power factor. They will be charging a power factor adjustment some time in the future, probably sooner than later. Crappy power factor is becoming a huge problem for the utilities because it distorts the AC waveform by introducing multiple harmonics in the sine wave. This cause losses in transformers especially that are optimized for 50 or 60 hz and are not designed to pass higher frequencies. It also causes greater losses in motors and just about anything with windings. It also produces a "false" peak load every cycle that isn't in step with the peak power of the AC waveform. That means the power company must size their equipment to handle a larger load than they are being paid to generate.

Power factor will instantly become a big deal when you are billed for poor power factor. One of the worst contributors now is cheap quality CFL bulbs. Also, anything with a dimmer or speed control is probably running with a poor power factor. Motors that run lightly loaded compared to their maximum capacity also run at a poor power factor.

Correcting this is in most cases as easy as placing a correctly sized capacitor on the individual motors and/or one at the main distribution box.

tmc_31
04-22-2010, 09:03 PM
Herm,

I spent 28 years with a major electric utility in Texas (11 years in the technical services dept). As a general rule power factor analysis was reserved for large industrial customers that used many motors, large and small. I can't remember a case where we recommended power factor correction for small commercial customers let alone a residential customer. The potential savings due to power factor correction for small customers is small at best.

As a general rule people hawking PF correction to small commercial and residential customers were regarded as snake oil salesmen.

I do not think PF correction will be cost effective for you at this time.

Tim

flathead4
04-22-2010, 09:09 PM
What percent of a typical homes electic bill goes to running motors? 10-20%? I don't know, but I'm pretty sure that the biggest load at my house is the hot water heater. And how much could you save in dollars if you corrected the PF of your home's motors? My gut feeling is that it wouldn't be anywhere near 30-40% of your total electric bill.

Tom

Forrest Addy
04-22-2010, 09:12 PM
Those residential power factor correction gimmicks are purest BS designed to separate you from your money rather than correct your power factor.

A watt hour meter algebraicly sums volts, amps and phase shift. The meter can't do it any differently because of the way they are designed. Correct your home power factor to unity of 100 or lag to a PF 70 the billig would cost the same for the same demand.

Presently you're a victim of the scam du jur: power factor gimmicks. The future may be different. You'll save more money if you switch from filament bulbs to LED same light output for 10% of the power consumption. Bypass fluorescent and compact fluorescent and go directly to LED. Oh, and put up a clothes line; clothes dryers suck electricity big time.

J Tiers
04-22-2010, 09:54 PM
I VERY much doubt that meters for residential will actually have power factor charges any time soon. The outcry would be extreme, and the benefit small other than for the sellers of capacitors.... There is very little that a homeowner can do to fix power factor, and a one-size fits all capacitor isn't it... I know, some of them switch.... fine,.......

The FACTS are that the powerco KNOWS what the average power factor is by area, or for residential, and they can do a block correction for a whole area..... complete with self adjustments, etc.

The MOST likely scenario is what the EC did, which is to require a good power factor on the EQUIPMENT. With so many motors now having an inverter right in/on them*, adding a PFC is relatively less burdensome than demanding that all the induction motors and CF lights...magically have over 0.8 PF or be billed to death.

The CFs are still not sufficiently penetrating the market, and most powercos are pushing them, bad PF and all.

* Both Emerson and GE are selling motors into the HVAC market that are variable speed motors with inverters built on. We are designing an upgraded system controller for a client of ours now, which talks to them.

Washing machines already do this as well. That takes care of many of the long-term motor loads in a typical house.

Richard-TX
04-22-2010, 11:08 PM
I read an article sometime with the last year where an engineer measured and placed a PF correction cap on a 1 hp motor. His total savings for the year amounted to about $0.33 Assuming the cap costs a nominal $7.00, he would break even in a little over 20 years. I doubt the cap would last that long.

The Artful Bodger
04-23-2010, 12:35 AM
Now hang on a minute. I always believed the consumer drag cup type meters measured true power and it was the supply company that missed out when power factor was off.

Black_Moons
04-23-2010, 12:50 AM
Im pertty sure the typical old style meter only reads true power. Newer digital meters it would not be very hard for them to also charge for apparent power.

I'll note that those 'capacitor' power factor correction devices can actualy make your power factor *worse* if they are left connected while no (or not enough) inductive power factor devices are running at the time.

And general motors are a TINY fraction of your power usage, Much more is spent on: Cooking, cloths drying, hot water heating, Heating of rooms, etc
If you have electric any of those, they are likey 90%+ of your bill, and they all run with a perfict power factor that would only be degraded by a 'correction' device.

Evan
04-23-2010, 02:39 AM
The average consumer residential power factor these days is a very poor 65 to 75% depending on the use of CFL lighting. The wattage shown on a CFL bulb is the amount of power that the old style Thompson meter will record. It isn't the actual load though. A 26 watt CFL presents a 40 watt load to the system because of the usually very poor power factor of around 50 to 60%.

This produces serious harmonics that cause increased losses in the network.


I VERY much doubt that meters for residential will actually have power factor charges any time soon. The outcry would be extreme, and the benefit small other than for the sellers of capacitors.... There is very little that a homeowner can do to fix power factor, and a one-size fits all capacitor isn't it... I know, some of them switch.... fine,.......



It is already being done but it isn't called "Power Factor Adjustment". Ontario is switching all customers to smart meters by the end of this year. They are also breaking down the billing to include a "Loss Factor". The "loss factor" represents in part the losses incurred when supplying reactive loads.



Usage and Factored Usage
When electricity is transported from the Provincial Transmission Grid to your residence, some of the electricity is used and/or lost as it travels through voltage transformers and distribution wires. In order to account for these losses, your total electricity consumption in kWh is multiplied by “The Total Loss Factor” to arrive at the number of kWh that are required to service your power needs.


http://www.kingstonhydro.com/Residential/Billing.aspx

I expect other utilities are either already doing this too or will in the very near future. The utilities really don't care if the residential customer can or cannot do anything about power factor. They just want to charge for it to cover their extra costs to supply reactive loads and to increase profits.

J Tiers
04-23-2010, 07:22 AM
It is already being done but it isn't called "Power Factor Adjustment". Ontario is switching all customers to smart meters by the end of this year. They are also breaking down the billing to include a "Loss Factor". The "loss factor" represents in part the losses incurred when supplying reactive loads.


So you are declaring that a specific part of your bill is based on the specific power factor of your house? Show us your bill and the "power factor adjustment".

I do NOT mean a generic "loss factor"....... re-read their explanation of that and you will see why.




I expect other utilities are either already doing this too or will in the very near future. The utilities really don't care if the residential customer can or cannot do anything about power factor. They just want to charge for it to cover their extra costs to supply reactive loads and to increase profits.

if you DO read the blurb, you will find that it is NOT AT ALL a power factor adjustment. it is an adjustment for the actual generated power required to get the power you really DO use TO your location, including ALL losses.

Even a transformer has straight resistive watt losses, and of course wires have resistive losses. Power factor simply makes those losses a bit more, depending on the actual PF.

it is also not a "specific" charge, for YOUR house. Note that the use of the word "factored" in their blurb does not imply a direct and specific relation to power "factor"....

As for poor PF, the powerco already compensates for "area-wide" PF loses, by putting compensating components, usually capacitors, on the line. To do otherwise, to fold their hands and squall, would be stupid. They are not stupid.

Adding MORE, usually raises voltage. An optimal amount provides correct voltage and reasonable power factor.


Here is the relevant text:

"Usage and Factored Usage

When electricity is transported from the Provincial Transmission Grid to your residence, some of the electricity is used and/or lost as it travels through voltage transformers and distribution wires. In order to account for these losses, your total electricity consumption in kWh is multiplied by “The Total Loss Factor” to arrive at the number of kWh that are required to service your power needs."

Evan
04-23-2010, 08:44 AM
As for poor PF, the powerco already compensates for "area-wide" PF loses, by putting compensating components, usually capacitors, on the line. To do otherwise, to fold their hands and squall, would be stupid. They are not stupid.


Well, they don't do that anyway at a local level. There are lots of studies done on that subject but very little action at the level of residential areas. Compensating capacitors must be at the level of individual transformers to do any good for residential housing.

As for the issue of losses, harmonics from poor power factor generate higher losses so if you are paying for losses you are also paying for poor power factors generally. It is broken down to zones, not to indvidual homes, but it is still a way to recover some of the cost of low power factor.

Energy prices will double in the next few years and there is a big push to put all energy products at parity with each other regardless of the cost of production. Energy is increasingly priced by the unit of heat it can produce rather than the gallon or cubic foot. You will see all possible costs being recovered in the near future. The moment that technology makes it possible to account for losses such as those created by less than unity power factors then it WILL be counted and billed soon after. It makes absolutely no difference how much people might scream and complain. They don't have an option.

When the power companies go up before a senate comittee and explain that these are real losses that cost real money and make the power system less efficient the comittee will have little choice but to go along with the companies.

JoeFin
04-23-2010, 08:56 AM
The average consumer residential power factor these days is a very poor 65 to 75% depending on the use of CFL lighting. The wattage shown on a CFL bulb is the amount of power that the old style Thompson meter will record. It isn't the actual load though. A 26 watt CFL presents a 40 watt load to the system because of the usually very poor power factor of around 50 to 60%.

This produces serious harmonics that cause increased losses in the network.



Even

We have had "Digital Metering" where I live you 15 years now and they have yet to charge a "Residential Customer" for KVAR.

The reason being is quite simple - the Utility providers would have to prove they are delivering .99pf power to your home and your load is reacting. Since residential customers "Share" transformers that is impossible if not difficult to do.

The local utility here in my area reserves KVAR charges, and Peak Demand charges for large industrial customers only.

Doesn't mean that the information can not be collected and examined to determine the need, size, and times for power factor correcting line capacitors.

ckelloug
04-23-2010, 09:39 AM
I believe Forrest is right that residential meters are not able to measure reactive power. Even if PF correcting your house helps the power company, I don't believe it will help you save on your bill.

Vern2
04-23-2010, 09:41 AM
What I think it is, is a big capacitor. The problem is it only works on 220v motors. Also you can only save if the power comes to you out of phase from the power company.

So basically small chance of savings. You wont live long enough to save any money.

Bottom line. Pass on this this one.

Vern

madman
04-23-2010, 10:30 AM
A three phase service in (yes hydro will do it) and a stepdown transformer for youre house needs will save you hydro.

JoeFin
04-23-2010, 10:47 AM
Even if PF correcting your house helps the power company, I don't believe it will help you save on your bill.

Any thing less then .99pf cost you money - period end of subject

The problem here being can YOU correct the power factor of everyone sharing the transformer with you

Evan
04-23-2010, 12:00 PM
We have had "Digital Metering" where I live you 15 years now and they have yet to charge a "Residential Customer" for KVAR.


Not all digital meters (in particular the early ones) can measure power in vs power out which is what they need to do to calculate power factor.



SMART METER:
A normal residential Smart Meter registers net absorbed energy (Er - Et). At the end of each measurement time interval the Smart Meter records the values of (Er - Et) and T. The difference between two successive recorded values is:
(Er - Et)b - (Er - Et)a = [(Erb - Etb) - (Era - Eta)] = [(Erb - Era) - (Etb - Eta)] = net absorbed energy during the measurement time interval.

SMARTER METER:
In order to permit directional energy calculations (required to calculate the power factor and to use different rates for received and transmitted power) the individual values of (Erb - Era) and (Etb - Eta) are required. A Smarter Meter registers Er and Et in separate registers using electronic signal processing. At the end of each measurement time interval the Smarter Meter records the values of Er, Et and T. The differences between successive recorded values are:
(Erb - Era) and (Etb - Eta)
A meter with this capability is also known as an interval directional kWh meter. Note that the net absorbed energy during a measurement time interval can be calculated by performing the subtraction:
[(Erb - Era) - (Etb - Eta)].

http://www.xylenepower.com/Electricity%20Metering.htm

ckelloug
04-23-2010, 12:13 PM
I beg to differ Mr. Fin:

See the first paragraph of:
http://www.analog.com/static/imported-files/tech_articles/16242282714726reactive_energy_metering_internation al_edition.pdf

Because the standard electromechanical residential meter is not a true RMS device, it cannot see reactive power. It is referred to in the IEC standards as an active power meter. One needs a VAR power meter to see reactive currents and they are normally not installed on households in the U.S. as far as I know. The full IEC standard is behind a paywall so I can't cite chapter and verse on this but from what I was taught, the power company ends up paying for or dealing with the reactive power, not you as a residential consumer.

--Cameron

JoeFin
04-23-2010, 03:16 PM
I beg to differ Mr. Fin:

Because the standard electromechanical residential meter is not a true RMS device,

--Cameron

I Agree whole heartedly

But I thought the conversation turned towards "Digital Meters" when Evan chimed in

But yes - Digital Utility Meters are True RMS - to a point. The Chief Engineer at Sunganamo told me they never tested any thing below a .70 pf and have no idea as to the accuracy of their meters in that environment

Ask me how I know that...

Black_Moons
04-23-2010, 03:25 PM
Another subnote is that a CFL while it has a poor power factor, it is neither laging or leading the AC wave, and therefor inductive/capactive correctors are usless for correcting for them.

CFL's and most other uncorrected loads that run on DC internaly draw current only at the peak of the AC wave.

Some modren computer power supplys are starting to have 'active' PFC correction however.. But no CFL's afaik.

2ManyHobbies
04-23-2010, 04:42 PM
My office power footprint is 63W at the moment. This is down from the ~250W I had running before. We swapped ~2kW of lighting for CFLs. The difference for us is not so much the energy saved in lighting or computers, but the difference in heating in the summertime. When the AC, washer, dryer, and dishwasher aren't going, we have to work pretty hard at a 500W draw. If I found out tomorrow that I was going to get charged for the PF, the first thing I'm going to look at fixing PF would be the compressors units for the AC. After that, I'd entertain PFC LEDs. The dishwasher and dryer won't make much of a mess because they are largely resistive loads.

If I thought I was losing a bank on PF issues on any switching power supplies, I'd probably see if I first could kill it with some ferrites and cord wraps on the worst offenders. It would probably take me an afternoon in front of the breaker panel with a scope to figure out if I had anything hiding, but I don't think I'd bother with a whole house system unless I had a pool, data center, or motors over 5HP that ran for hours on end. Consumer electronics will tout PFC once California power companies change their billing.

What I'm really interested in is peak vs off peak pricing with smart meters. I see that showing up in a monthly bill before PF charges. For the worst hogs in the house, you could use switched outlets and just have a computer disable the outlets when it determines peak time is at hand. Washer, dryer, dishwasher, electric car charger, etc. If peak pricing goes hand in hand with the price power companies will pay individuals for microgeneration, then I can justify solar and probably wind up with a net $0 power bill over 12 months. I'd still take a hit on natural gas in the winter though.

Evan
04-23-2010, 05:40 PM
I am currently switching over to LED lighting and expect to have the house 90% LED within a year or so. Right now we use some LED and the rest is almost entirely CFL. I had a look at my line voltage with my new-to-me scope recently and was surprised how bad the waveform looks. It isn't even close to a decent sine wave. I wish I had a distortion analyzer so I could actually quantify the level of harmonics but the wave really looks crappy.

I think I will post a picture later. Even though LEDs are non linear devices they will greatly reduce the power factor issue because they greatly reduce the consumption. My living room is now running on 50 watts of LED lighting and the light levels are even better than they were before.

jugs
04-23-2010, 05:45 PM
I Agree whole heartedly

But I thought the conversation turned towards "Digital Meters" when Evan chimed in

But yes - Digital Utility Meters are True RMS - to a point. The Chief Engineer at Sunganamo told me they never tested any thing below a .70 pf and have no idea as to the accuracy of their meters in that environment

Ask me how I know that...

How do you know that ? :D

metalmagpie
04-23-2010, 06:15 PM
I agree with Forrest. Save your money.

As regards power factor correction on phase converters, welders, or other inductive loads, I thought hard about it once and realized the only possible savings to me by correcting the power factor perfectly is to be able to buy slightly smaller copper wiring to hook the thing up. Which isn't much when you consider it's a minimal one-time savings versus the initial expense of a bunch of big run capacitors, a box to put them in etc., and the ongoing expense of replacing the caps as they go bad over the years. I might have made a mistake on my reasoning, maybe there's another way that PF caps save money, but I'm confident that if so, one of you guys much smarter than I am will "correct" me (pun intended). :-)

metalmagpie

J Tiers
04-23-2010, 09:21 PM
Compensating capacitors must be at the level of individual transformers to do any good for residential housing.


When the power companies go up before a senate comittee and explain that these are real losses that cost real money and make the power system less efficient the comittee will have little choice but to go along with the companies.

1) Area compensation insulates the power company from the local poor power factor......... the powerco can and does compensate on feeder lines etc, and it does make the downstream PF "invisible" to them, aside from its effect on pure watt losses.

There would be no difference to that if the individual houses were compensated, other than the fact that a lot would be OVER compensated, raising the local voltage and making it unstable.

PF compensation by adding local capacitors, RAISES voltage, and too much is a bad thing.

Now, having the various devices draw @ unity power factor would be fine. It is not difficult to put together a circuit which has literally only milliamperes of harmonic current, despite drawing 30+ amperes average and feeding a DC bus. Normally, that would be a transformer and rectifiers, and would have a crummy PF in the area of 0.6 or so.

2) The senate etc doesn't deal with them...... Power companies deal with state Public Service Commissions. It is a state matter and the PSC can do whatever it wants....subject to oversight from the state legislatures that set it up. And they tend not to view the powerco, gas co, etc with a universally favorable eye.

The problem of dealing with millions of individual PF loads is just not something the powerco wants to do.

JoeFin
04-23-2010, 09:49 PM
I Agree whole heartedly

But I thought the conversation turned towards "Digital Meters" when Evan chimed in

But yes - Digital Utility Meters are True RMS - to a point. The Chief Engineer at Sunganamo told me they never tested any thing below a .70 pf and have no idea as to the accuracy of their meters in that environment

Ask me how I know that...

How do you know that ? :D

I had to perform a Power Quality Analysis at a facility whose normal consumption was between 16 - 20 MegaWatts. Privately owned 230Kv Substation dual feed directly off 2 grids, Transformed down to 21.5Kv Radial Distribution and then to 480 transformers through out the many buildings of the 100 acre facility

1 of the buildings there was leased by the Federal Government and housed the manufacturing capabilities of a couple components of US Currency. 1 in particular was that thin silver stripe you can see in a $20 dollar bill.

I clamped on a Dranitz 3 phase True Harmonic Analyzer to the 21.5Kv feed side of the transformer feeding that machine and "Whaa-La" .67pf

Inside was banks and banks of the old SCR style rectifiers

That 1 machine was dragging down the power factor of the whole 100 acre facility

Black_Moons
04-23-2010, 10:38 PM
Yea and if you charge em for thier poor power factor, they will just print more money to cover the cost.. causeing inflation that devalues your entire company. Nice catch 22. :)

Evan
04-24-2010, 12:40 AM
The problem of dealing with millions of individual PF loads is just not something the powerco wants to do.

They may not want to but they have no choice. The real problem is the distortion of the waveform. The situation with harmonics is making the entire grid unstable and inefficient. Waveform quality is the number one problem for every power company today.

I just took a picture of what my power looks like. It is terrible and I would guess that the distortion is near the 10% mark if not more. That is really bad and can cause many problems both with my equipment and on the distribution system. If you are using devices that produce harmonic power as a result of non linear power transformation then that harmonic energy is transmitted back out onto the distribution system. Since the grid is all in sync over large areas everybody's contribution to that distorted power is also in sync so that it is all additive.

This picture shows how bad it s.

http://ixian.ca/pics7/pfactor.jpg

Evan
04-24-2010, 12:49 AM
) The senate etc doesn't deal with them......

Oh really?

http://ixian.ca/pics7/senate.jpg

http://www.ieca-us.com/documents/MWVIECACHPWrittenTestimonyMay72009Senate.pdf

J Tiers
04-24-2010, 08:07 AM
They may not want to but they have no choice. The real problem is the distortion of the waveform. The situation with harmonics is making the entire grid unstable and inefficient. Waveform quality is the number one problem for every power company today.

The power company has had to deal with poor power factor for a hundred years. Industrial plants have had exceptionally poor power factor for a long time. This was dealt with by capacitive compensation.

Now that the industrial loads are all gone to china, large quantities of rotten power factor loads are gone with them.

Homes have generally a lower load, more of it is resistive with a 1.0 PF (water heaters, stoves, electric heat), and their usage, plus power factor vs time of day is fairly predictable.

Capacitive compensation worked a long time ago, and it STILL works.... Not only does it compensate the load inductance, but it also "bypasses" the harmonics, preventing them from traveling farther.

Compensating an AREA load prevents the potentially bad power factor of that area load from being "seen" at the supply end. So the generators do NOT have to deal with it, aside from the increase in actual LOCAL watt load that a lower PF causes.

Everything "upstream" from the compensation point is "immune" to the load's poor power factor. There are NO increased losses due to PF "upstream" of the compensation aside from the increased LOCAL watt load (depending on what degree of compensation is done, of course).

PF-related losses are therefore limited to the uncompensated area.

In Europe, the standard practise is apparently to drastically undersize the neutral, which can then be relatively easily overloaded by harmonics, which tend not to cancel with a balanced load the way the main watt load does. Therefore they have been demanding new devices have a good power factor (near 1.0) for some time.

In the US, neutrals have not been so drastically undersized, and the main issue with low PF is the increase in distribution losses that occurs even with a properly compensated load. There is however some effect of increased neutral current here also. But the distribution system doesn't have a neutral in the same way....

The power company could make more money if they could burn the same coal, but sell 10% or 15% more power. If they can reduce distribution losses, they may get a reduction in the watt losses in distribution, and so send more BILLABLE power over the same wires.

With the furor over "carbon pollution", they would very much like to be prepared by getting that sort of increase in billable from the same tonnage burnt.

Since increasingly every device, even a gas stove requires electricity to operate, more loads are being added.

By the way, every distribution transformer on earth has a "percent impedance", which represents essentially the transformer impedance divided by the load impedance. That impedance is often in the 4 to 6% area, and is nearly all inductive (same as the typical bad PF load).

So the distribution system ADDS to the poor power factor, and it is relatively difficult to avoid that, so it must be compensated.



I just took a picture of what my power looks like. It is terrible and I would guess that the distortion is near the 10% mark if not more. That is really bad and can cause many problems both with my equipment and on the distribution system.

That is actually not that bad...... I have seen quite a bit worse in industrial areas.

And, that distortion is probably FROM YOUR HOUSE. You have stated that your nearest neighbors are some distance (maybe a mile??) away, so you likely have a local transformer, probably with at least a 6% impedance....

Therefore, there is a very good chance that you are seeing what YOUR HOUSE does to the line, plus the effect of what other "nearby" houses add to that.

it doe not take much to make that sort of distortion, and that might be as little as 4 or 5% THD. it is more typical to see a 'flat-topping" of the sine (3rd harmonic), the "notch" in the side of the wave may be a phase-controlled load of some sort (triac controller).

With a little ingenuity, you could probably whip up a tunable circuit to discover exactly what the harmonic content is.


As for the Senate... of course the congresscritters hold hearings, and set national policy. But the implementation and rate structure is set by the state PSC, in response to requests from the various state regulated utilities.

If a powerco wanted to start charging individual households for PF, they would do that through the state PSC just as they do all rate changes now. Per Joefin, apparently they have had the capability in his area for some years, and have yet to try to do it.

In fact, the powercos have been "pushing" CF bulbs for years, and show NO signs of stopping now.

The facts are that while the CF has a poor power factor, EVEN WITH THAT, the total load is less than the replaced incandescent bulb. That makes it a "win" overall as far as reducing net load on the generating capacity.

A CF with "100W equivalent" light output may draw 33 watts. Assuming a PF of 0.6, the net VA draw is 55 watts. Despite the PF, that nets out as saving 45 VA per bulb.

It is not too shabby to save 45% of the total generating capacity needed to light that area..... PF or no PF. The added savings from a 1.0 PF would only be 22% additional (based on 100W), so 2/3 of the net saving is already accomplished by the switchover to the CF. The next 22% could be disproportionately expensive vs the energy saving.

kjbllc
04-24-2010, 09:07 AM
HOw are LED's going to fit into this. I don't know a lot about electronics, so I was wondering if the LED's would add subtract or have no difference in harmonic distortion.
I have just gotten some LED's and they work well, I expect as they improve and become more popular the CF bulbs will be out the door faster than then the incandescence bulbs. were.

Evan
04-24-2010, 09:19 AM
I am sure that the distortion is from my house as I use CFL bulbs for nearly everything. I have no triac controlled devices that run in the background, no fan or light dimmers. The point is that CFL bulbs are very popular here and this sort of distortion is almost certainly the norm. Note that the sides of the wave are nearly straight to the point that it resembles a triangle wave meaning that it contains a large number of odd harmonics. A lot of that doesn't make it back out through the transformer so a significant amount of that reactive load becomes a true load to the utility but isn't picked up by my meter.

The only capacitors used here are on the large district feeders to bump up the voltage. There is one halfway from here to town but that is all. I have a very significant motor load that runs at a very poor power factor and it can't be helped. Our well is 350 feet deep and the pump is one horsepower. Because of the depth it can't come close to delivering full volume so the result is that the pump is mostly churning instead of pumping. That means it is lightly loaded because it isn't moving much water.

Controlling harmonic content is the number one most important problem the utilities have now. It makes it extremely difficult to match phase between systems when they need to be connected on the grid.

J Tiers
04-24-2010, 09:50 AM
The only capacitors used here are on the large district feeders to bump up the voltage. There is one halfway from here to town but that is all.

That's the point entirely.

"bumping up the voltage" is "tuning the load" which is the same thing as compensating for lagging reactive load (the normal type).

You may recall that when a tuned circuit is 'tuned" to a particular frequency, ALL the reactive loads drop out at that frequency, and ONLY the resistive load remains.....

Power factor correction is much the same..... but the reacive component is typically not 100% compensated, because doing so is
1) uneconomical (diminishing returns)

2) difficult because of the changing nature of the load

3) because a full compensation would result in a high "Q", and potentially large load dependent voltage variations above the nominal mains voltage.

The voltage 'raising" is, simply stated, because compensating (removing) the SERIES inductive components also effectively removes their voltage drops and drives teh phase back towards unityPF.

Compensating the load reactance drives the phase back towards a unity power factor as well as raising voltage in part due to lowering the total VA load.

OVER-compensating the load raises voltage too much, and makes it more load-dependent.

fasto
04-24-2010, 10:16 AM
How did I know this thread would turn into a contest?

I've been making hardware to do PF compensation for the utilities at my own company for 6 years, and I worked in the field for 10-odd years before that. My business partner has twice that experience at several multinational companies, etc. We sell hardware to the biggest utility in the U.S., as well as many smaller utilities, including one that has a total of 4,000 customers. (My website, I didn't design it: www.psinteg.com)

The biggest problem facing utility companies in the U.S. is the loss of experienced linemen, splicers, foreman, engineers, and so on.

No residential customer in the US can be charged for bad PF - yet. The utilities add capacitors, usually one every few miles on a residential distribution circuit, for 2 reasons. To improve voltage at the expense of leading PF to overcome I^2*R losses, and to mitigate lagging PF from motor loads which are mainly air conditioners in a residential situation. Most utilities don't even bother to measure PF to switch the caps in & out as that's really expensive. By and large utilities switch caps based on either voltage or ambient temperature. (Really! Remember those air conditioners!)

My cap control can switch based on VAr (which is used instead of PF), Primary Amps, Primary or Secondary Volts, Temperature, Time, Date, by remote control, or any combination of those. 90%+ of the utilities use secondary voltage.

Unless you have a PQ agreement, the utility doesn't care about how your voltage waveforms look. Are the lights on? Is anything on fire? Is the voltage on spec? That's what they care about, in that order.

Evan
04-24-2010, 01:36 PM
We don't have capacitors here every few miles. As I wrote previously there is only the one large capacitor bank about the size of a car on a platform that corrects the phase difference. That is it for this circuit that extends about 60 miles from town. However, we also don't have air conditioners in most houses either. Well pumps are really common but that load is very intermittent. There is a study of the possible benefits of putting power factor correction on each transformer and it turns out that contrary to Jerry's estimation it has a quick payback for the utility.




To get a real understanding of positive impact power factor correction has on generation costs
benefit analysis was carried out to see if such a project would make sense on mass. Four
assumptions where used in this analysis:

1. a typical home has a 5kW demand
2. the cost of new generation is about $1,000,000 an MVA
3. a typical homes power factor is improved from 87% to 99% when 3.34 KVAR of
capacitance is add
4. the cost of the Power Medix units is $450,000 installed

With an example of 1000 homes each using the above information, the generation requirement
would be 5.75MVA (5kW/.87PF x 1000). By installing capacitance at the residential level the
requirement of the generator for the 1000 homes would now only be 5.05MVA (5kW/.99PF X
1000) or 700 KVA less.

Therefore the cost to generate 700 KVA would be $700,000 (.700MVA X $1,000,000). The cost
to supply and install capacitance at the residential level to free up the same amount of
capacitance would be $450,000. The environment and health costs associated with the
generation of electricity are also removed making the economics even stronger.

The pilot project showed that the installation of capacitors at the residential level is a viable
option in freeing up capacitance within the province is deployed on mass. The savings can also
be achieved without having the customer drastically changing their lifestyle.


http://www.mearie.ca/LDC_tomorrow_fund/Residential_Power_Factor_Porrection_Project_2005.p df

Barrington
04-24-2010, 02:24 PM
There is a study of the possible benefits of putting power factor correction on each transformer and it turns out that contrary to Jerry's estimation it has a quick payback for the utility.The study quoted is actually about installing capacitors in the houses, not on the transformers.

Cheers

.

Evan
04-24-2010, 03:58 PM
The difference is nil. There would be the same benefit if the correction capacitors were installed on the transformer as the extra distance to the load is inconsequential. As long as the correction is applied on the user side of the transformer the result is the same.

The Artful Bodger
04-24-2010, 04:45 PM
The difference is nil. There would be the same benefit if the correction capacitors were installed on the transformer as the extra distance to the load is inconsequential. As long as the correction is applied on the user side of the transformer the result is the same.

Correcting the power factor at the load reduces the R losses in the transmission lines.

Evan
04-24-2010, 05:59 PM
Those lines are very short so it makes no detectable difference. The distance to the furthest house from a pad transformer in a subdivision is no more than a few hundred feet. It also isn't what the utility is concerned about. It appears that they happen to be testing a product that goes in the house. It can just as well go on the transformer. When I wrote "on each transformer" my meaning was correction applied to the loads "on each transformer". Regardless of how you wish to interpret it the effect is the same.

Now, exactly what have these posts by you and Barrington illuminated?

Barrington
04-24-2010, 07:16 PM
I was merely 'illuminating ' the fact that "Whitby Hydro" study quoted is concerned with fitting power factor correction at individual houses, rather than local transformers.

This must surely be a more costly and logistically difficult approach, both for the pilot study and any eventual implementation. I'm not clear as to why they would consider going down this route ?

Cheers

.

Evan
04-24-2010, 08:18 PM
My guess is that the manufacturer supplied the units at no cost for the study. They may have even paid for the exercise as a marketing tool to the utilities.

There are countries where power factor is billed at the residential level.

J Tiers
04-24-2010, 09:16 PM
it turns out that contrary to Jerry's estimation it has a quick payback for the utility.



Of course I said no such thing whatever.......

I suggested that most of the effect could be duplicated by area correction, with less hassle, and that is true.

The installation of PF correction ANYWHERE in the line system insulates the generator from the direct PF problems..... the amount of increased distribution watt loss incurred by moving the correction back into the distribution system closer to the generator depends on the length of the lines, and the losses in them due to the higher currents from the PF load.

For instance....

1) The correction can be installed at the house.

2) The correction can be installed at the local transformer primary, which covers several houses in areas denser than Evan's neighborhood

2A) the correction can be installed at the local transformer secondary (ditto)

3) the correction can be installed at the area substation, on the medium voltage distribution line.

In case 3, there is an advantage, in that voltage can be more easily monitored and maintained. Also, the diversity of loads tends to make an average correction less sensitive to individual loads.
The disadvantage is that you forgo the correction of PF-increased losses between the substation and the customer, in local transformers, and lines. If the capacitors are placed somewhere along the lines, some of that can be corrected as well.

Case 2 is essentially case 3 with the capacitors distributed all over, one per transformer at the input terminals. Each one will be much smaller, but teh aggregate microfarad value (or kvars) will be lightly larger than in case 3

Case 2A gives reasonable diversity, since the capacitor is directly on the line for several houses, typically only a couple hundred feet of wire.... But there is the danger of overcompensation, which would locally raise the voltage out of the allowable specs, if the houses all have a low power usage.... And, teh capacitance must be several times that which is required at the primary (depending on the distribution voltage).
It is quite possible for the net usage of several houses to be less than 3.3 kvar overnight, or at certain times of the year, let alone the 3.3kvar PER HOUSE they suggest.
Some of that increased voltage would be reflected back on the line, of course. But a local transformer is typically a higher impedance device, and the secondary voltage might be a few percent higher than expected.

Case 1 offers hardly any advantage over case 2A, if any, merely multiplying units. Case 2 (not 2A) is what I assume Evan refers to.

BOTH case 1 and 2A have the advantage of *fully* compensating the distribution system, but it comes at the cost of risking local over-voltages which the utility would never know about, during times of lower load in those houses.... if your neighbors are out of town, they draw little or nothing, and you may find that the total compensation is larger than your own usage, with the potential for voltages over nominal limits.
Case 2 avoids that, by allowing the effect to be seen at the substation or other monitoring point directly.

I will also say that trying for the 0.99 PF that was suggested in Evan's quote is pretty extreme.... and cannot be consistently obtained with a single capacitor value and and a variable load. At some times you will be undercompensated, with a voltage drop, and at others you will have a significant leading power factor, with a possibility of local overvoltage.


In any case, NO installation of local capacitors in your house at your expense, will, at the present time or immediate future, save you one thin dime on your bill.

The meters have a correction in them to REJECT reactive power, they respond ONLY to 'real" power, and that is what you are billed for.

Therefore, RIGHT NOW, there is not one single reason to pay hundreds of dollars to install any capacitors. The capacitor you install must be much larger than the one the powerco would install at the primary, since teh voltage is much lower at the secondary.

If the powerco wants to do it at the transformer, let them. It probably will not affect you too negatively, except when the new bill arrives with the increased charges to service the debt incurred for installing all those capacitors.

By the way, manufacturing all those capacitors will be a heck of a load..... at the present time, most kvar capacitors are on 12 week backorder...... They would have to come from china...... one hopes they would be better than the chinese motors, but.....

Evan
04-25-2010, 12:11 AM
Of course I said no such thing whatever.......


Sure you did Jerry.



The problem of dealing with millions of individual PF loads is just not something the powerco wants to do.

BTW, nobody said it would be at your expense. The calculations in the study assume the utility pays for it.


If the powerco wants to do it at the transformer, let them. It probably will not affect you too negatively, except when the new bill arrives with the increased charges to service the debt incurred for installing all those capacitors.



The point of the study is that your new higher bill won't be as high as it would be if they didn't put on the PF correction since building new capacity is always more expensive than conservation measures.

J Tiers
04-25-2010, 10:17 AM
Sure you did Jerry.


Show me where I said that, because I have looked over what I wrote...... and I did not....

I said it has been uneconomical, and THAT is true...... if it paid off AND if the other problems were not overwhelming, it would have been done.

it is possible that it can BECOME economical, to allow avoiding added coal plants, etc. But it is a limited resource, since the ideal case is to avoid the low PF loads.

See my prior post refuting the "huge CF bulb PF problem"..... because the TOTAL KVA is reduced 45% or so by using CFs, PF or no PF.

The "study" made some assumptions..... it, and its conclusions, are only as valid as those assumptions are.


1. a typical home has a 5kW demand
2. the cost of new generation is about $1,000,000 an MVA
3. a typical homes power factor is improved from 87% to 99% when 3.34 KVAR of
capacitance is add
4. the cost of the Power Medix units is $450,000 installed


I suspect that these were figured to make teh numbers come out right.........

item 1 is a problem right away... I can tell you OUR house has not got 5kW in loads...... and never did, even with the old electric stove, at least as a continuous load.
The reason for the 5KW load per house is probably that it requires sufficiently few houses per MVA that the cost of the capacitor units does not exceed the cost of new generation.

item 2 I will take as-read, no better information.

Item 3 is pretty dubious..... 0.99 is pretty darn good, and I can be quite certain it won't be attained much of the time..... overnight it is quite possible the PF will go back down to 0.88 *or lower* LEADING. A large number of houses all contributing a leading power factor is not much if any better than a large number with a LAGGING PF.

One may assume that it will cancel lagging PF elsewhere, but overnight the total load is low, and tens of thousands of houses with 3.3kvars leading per house is quite possibly too much of a good thing. 3.3 kvar will usually compensate about a 15 HP 3 phase motor, how many of those do you have running all night at YOUR house?.

item 4 I have no information on, and take as-read.

All in all, the "study" appears to be somewhat flawed, at least for this area. If all you folks in Canada have electric heat, it might be more reasonable, but electric heat has usually got a pretty good PF, if it is not triac modulated, and that large 0.99 load would tend to improve the average PF.




BTW, nobody said it would be at your expense. The calculations in the study assume the utility pays for it.


Don't you pay a bill? if so then YOU pay for it.



The point of the study is that your new higher bill won't be as high as it would be if they didn't put on the PF correction since building new capacity is always more expensive than conservation measures.

Don't suppose for a minute that your bill won't be affected...... Someone will pay for all those capacitors, which cost over $100 each, even in quantity.

Evan
04-25-2010, 11:01 AM
5kw in loads is nothing. Sound like an underestimate to me. Electric water heat, stove, microwave, toaster oven, dryer, indoor lighting, air handling equipment, AV equipment, plugins for the cars in winter, computers, security equipment, electric lawnmower and snowblower, hot tub heater and pump, outdoor lighting and all those hidden parasitic loads that draw power even when the equipment is "off".

Note that I haven't included electric heat, well pump, electric barbeque, built in vacuum, ceiling fans, infrared heat in the bathrooms, garbage disposal, airconditioning (east coast and central), rechargeable tools and toys and whatever else I have forgotten to mention.


See my prior post refuting the "huge CF bulb PF problem"..... because the TOTAL KVA is reduced 45% or so by using CFs, PF or no PF.


The distortion is still increased regardless of the reduction in load. That is the major problem with CFLs since they can't be compensated with capacitors. Look at my waveform again. You can see that the wave is notched on both sides of 100% and that is the main contribution from CFLs.


Don't suppose for a minute that your bill won't be affected...... Someone will pay for all those capacitors, which cost over $100 each, even in quantity.

I didn't say that. Read it again.

Paul Alciatore
04-25-2010, 01:43 PM
Bottom line:

1. Not much use in trying to compensate PF in a residence. It will cost far more than it will save, if it saves anything anyway.

2. You will pay for it no matter what as the power company must pay it's expenses and if it must generate more power to account for PF, then that expense must be passed on to the customers. To not do so would bankrupt them and they would go out of business. So, separate charge or higher rate or whatever, you do pay for it.

J Tiers
04-25-2010, 01:56 PM
5kw in loads is nothing. Sound like an underestimate to me. Electric water heat, stove, microwave, toaster oven, dryer, indoor lighting, air handling equipment, AV equipment, plugins for the cars in winter, computers, security equipment, electric lawnmower and snowblower, hot tub heater and pump, outdoor lighting and all those hidden parasitic loads that draw power even when the equipment is "off".

Note that I haven't included electric heat, well pump, electric barbeque, built in vacuum, ceiling fans, infrared heat in the bathrooms, garbage disposal, airconditioning (east coast and central), rechargeable tools and toys and whatever else I have forgotten to mention.


Leaving aside the transient loads which are on 20 min in 24 hours max, like microwave oven, disposal (a pox on all of them) and the maybe 5 watt per device (for hungry non-energy-star appliances) "ghost" loads.....

I have put in bold the items which do NOT apply to us, for instance...... and not to most of our neighbors (leaving aside A/C in summer, we are weird and don't have it). Our outdoor lighting is solar from the array on the shed, and what electric lawn tools we have run from that also.

Frankly, it is rather arrogant to assume that an AVERAGE 5KW load is typical...... maybe for the "woodwaster" houses for yuppies. Not around here. Even though it is for Canada, it sounds more like a 'foreigner's" poor opinion of Americans, and you are not quite a "foreigner".

if they had said 5KWH per day (5 kilowatt hours per day), that would have been much more believable..... I have the powerco report on our usage....... and 5 KWH per day is much more like it than 5 KW average.

kc5ezc
04-25-2010, 06:27 PM
JTiers: Re the Senate getting involved in the power business/
Google Federal Energy Regulatory Commission and see how involved they are. The states have their playpen, but the FERC covers them all. Some of the most convoluted, complex issues I have ever dealt with are power generation and transmission. Not the engineering issues, but the policy issues. I will leave the engineering issues to be sorted by 'a competent person' as Sir John would call him.
Thanks for an interesting discussion.
John B

Evan
04-25-2010, 06:37 PM
Jerry,

If you are going to operate under the assumption that the study is a bunch of lies then there is no basis for a reasonable discussion.

Pretty arrogant of you.

J Tiers
04-25-2010, 09:05 PM
Jerry,

If you are going to operate under the assumption that the study is a bunch of lies then there is no basis for a reasonable discussion.

Pretty arrogant of you.


Arrogant? What an odd conclusion for you to come to. I explained why I did not believe they used reasonable assumptions, which would not make the study a "bunch of lies" as you claim.

Biased assumptions, given plainly and up-front do not make the study a "bunch of lies", but they WOULD make the conclusions *a bit suspect*, (at least), insofar as it's applicability to real-world conditions.

It is up to "them", or, if you wish to discuss it, YOU, to explain why you think the assumptions ARE reasonable...... assuming you do.

I don't agree with their assumptions, since I see that they do not look reasonable from my own knowledge. And I very much suspect , since there is a particular brand name mentioned, that it is NOT a general view of local compensation, but rather a bid for installing the particular branded device on the low voltage side.

One is free to assume that other devices, of possibly significantly lower cost, would do just as well as the "branded device".

I further see that the "slant" of the assumptions appears to be such as to make the use of the particular brand-name product look reasonable. This is because it both minimizes the total number of their devices needed per MVA, AND decreases the number of houses served per MVA. That makes generation look expensive, while reducing the apparent relative cost of their device.

And then, when I know that the size of the capacitor in uF is considerably smaller (and cheaper) when installed on the medium voltage side of the final transformer, AND I know that the branded device wouldn't likely be put there..... well, the cat is out of THAT bag.....

I suspect it is a bid to get a powerco-approved installation, with which to produce advertisements.....

But I am a suspicious son-of-a-gun who didn't fall off the turnip truck today.

it is possible that my jaundiced view is incorrect, but from what I can see, nothing suggests that very strongly at all.

In any case, despite the fact that you (the aggregate consumer of power) pay for all the costs, including reactive losses, etc, installing several hundred dollars of local capacitor will only make the powerco a tiny fraction happier, it won't make your electricity one whit cheaper.

Evan
04-25-2010, 09:15 PM
According to Natural Resources Canada the average electrical power use in British Columbia is 3kwh 24/7 per household. This includes all households from apartments to single family detached housing and also includes all climate zones in the province. For just single family detached housing outside of the southern temperate zone the figures will be much higher.

http://www.oee.nrcan.gc.ca/corporate/statistics/neud/dpa/tablestrends2/res_bct_1_e_4.cfm?attr=0

J Tiers
04-25-2010, 10:02 PM
You folks are some real power HOGS.......... I will say that I was NOT aware that you used that much power....... it is not typical down here, nor even in Minnesota, where I grew up. Someone must have sold a lot of electric heat.

All the numbers I can find point to about 1100 to 1500w average consumption in the US..... (1.1 kw to 1.5 KW)

You folks seem to be power hogs...... but you gave the figure as kwh AND attached a time period to it, which is not correct use of units.... are you sure?

But 3 kva still isn't 5 kva.

AND, that amount of power HAS to be including electric heaters...... Electric heaters are NOT a power factor problem. if anything, they IMPROVE the power factor, on average.

regardless of that power used figure, which I frankly find surprising, and even suspect, there is NO advantage as far as generation from capacitors for any 1.0 power factor load, such as heaters.

The only improvement capacitors give is to the lagging PF load component.

We have gas furnaces of around 100,000 btu/hr. 1 kw is about 3400 btu/hr, so 100,000 btu/hr, which probably is low for BC temperatures...... would be 100,000/3400 = 29 kW electric furnace.

The fan motor for a typical furnace is around 1 HP, drawing about 1 kW at a PF of perhaps 0.6, or about 1.6 kVA.

Summing those up already gives a power factor of something better than 0.98....... you really cannot expect to do better than that, and no capacitors required.

Optics Curmudgeon
04-25-2010, 11:17 PM
Just for reference (not here to argue), PG&E recently installed one of these: http://www.landisgyr.com/ap//files/pdf1/FOCUS_AX_Universal_RF_Sell_Sheet.pdf on my house. It's completely electronic, no moving parts. Capable of measuring power factor, but when I asked PG&E (locally known as Pillage, Gouge and Extort) they say that there is no plan to measure PF on residential services, and that the Public Utilities Commission currently does not allow it.

Joe

Evan
04-26-2010, 12:19 AM
This is a cold climate Jerry. You live in the south so you have no idea. There is no frost free season here and the temperature was below freezing this am.

According to that table about 60% use natural gas heat like we do. Winter time is hard on the electric bill for several reasons. It's dark for up to 16 hours per day. The largest power consumer though is heating water. Our water comes in from the ground only a few degrees above freezing. Even with our hot water set to only 115F it takes a LOT of energy to get it up there.

3KVA is the average and that includes apartments. Single family homes draw around 5 to 7 KVA which is what they studied. I draw about 3.5 because of the various power saving measures like solar preheating of my incoming water. If we used electric heat out consumption would triple. About the only place you find electric heat is in apartments where wood heating isn't an option. Also, the car engine heaters I mentioned are not a small item. If you want your car to start during about 3 months of the year you plug it in. The average block heater draws around 800 to 1000 watts. When it is really cold you plug it in at work too.

There is no reason to doubt the conclusions of that study. It doesn't apply to you but that doesn't mean it is flawed.


but you gave the figure as kwh AND attached a time period to it, which is not correct use of units

Total annual consumption divided by the number of hours in a year.

Bguns
04-26-2010, 12:37 AM
I just looked at my electric bill...

24 hours, say 30 days a month ~1.44 average kw per hour. In mid winter..
Looked at year round billing, and in summer, only 75% of above..

Alaska, with a cold water well, welders, mill, lathes and even a electric water heater/dryer... Gas heat.

Even less light than Williams Lake, and ~10 miles downstream from a Glacier...

I turn my lights out when not needed, etc...

Evan
04-26-2010, 04:23 AM
Palmer is a lot warmer than the interior of BC. You are at sea level by the ocean and that has a major moderating effect on temperature. Williams lake is often the coldest place in BC and from time to time the coldest in North America. The record low here is about -50F and we have record wind chill days in every month of the year. The lake is frozen for about 4 months of the year.

You also have much more snow in the winter than we do. That makes a huge difference to heat loss in a house. Snow is an excellent insulator and we often have none when the temperature drops to -40 or so which it does nearly every year.

I cannot find temperature records for heating degree days that are based on the same base standard so I cannot compare that but just the fact of being at sea level by the ocean insures that your climate is much more moderate than here.

J Tiers
04-26-2010, 07:25 AM
This is a cold climate Jerry. You live in the south so you have no idea. There is no frost free season here and the temperature was below freezing this am.

I dunno if you should brag so much.

LIKE YOU, I USED TO live in quite a DIFFERENT climate to what I live in now.......

YOU lived in a WARM climate...... California coast...... (OK, OK see mark Twain's comment)

I, on the other hand, lived in Minnesota, with -38 C winter temps. We got the cold air after you were done with it. The main difference is a bit more light, and not as long a winter.

Do not be so arrogant as to say "you have no idea".....

Even here, it happily gets to -15C in the winter, so I still get a piece of the old country, plenty enough for me.

And, to balance the cold, we get A/C loads in summer...... those who use A/C (which we do not), including most of the populace, have a 1HP chiller motor plus a 3/4 to 1 HP ventilating fan running quite a bit of the time.....

And lots of people have wells... a fair number use electric heat, particularly in farther south areas. But teh average consumption seems to be rather less.

If the 3 kw is normal, I'll go with that, but even if the 3kw load is average, that STILL is not 5 kw......... so the study still looks biased to me, and I have trouble seeing how they get there without some PF-improving electric heaters.

Evan
04-26-2010, 09:08 AM
You aren't reading again Jerry. For single family dwelling the norm is 5 or so just like the graphs of useage show in the study.

It is difficult to determine the actual statistical weather conditions because of the use of means and averages. We can have nightime lows right now of -10 that warms up to +20 by afternoon. The average for the day will show above freezing so the degree day calculation will be completely out to lunch.

We have cut our useage every year to the point that now we are using less than half the average consumption for a house the size of ours. I just checked the latest bill online and for the last 2 months we averaged 1.54kwatts per hour. That is better than I expected and is in part due to the lack of really cold weather the last two months. The solar water preheater is also a big factor. Yesterday was the first really sunny day for a while and the 45 gallon tank of water that is the heat exchanger had dropped to only 66F. I ran the circulating pump all day which cost around 1kwh of electricity but it raised the temperature of the tank from 66F to 80F which pays back that power by 3 to 4 times.

2ManyHobbies
04-26-2010, 01:52 PM
Evan is highly productive in the home shop because in addition to only having sunlight 3 months a year, it is too dang cold to go out and do anything even when the sun is shining. :eek:

J Tiers
04-26-2010, 08:41 PM
You aren't reading again Jerry. For single family dwelling the norm is 5 or so just like the graphs of useage show in the study.



You are correct, I used your summary instead of digging through the dense language and tables you linked to. Your summary was:


According to Natural Resources Canada the average electrical power use in British Columbia is 3kwh 24/7 per household. This includes all households from apartments to single family detached housing and also includes all climate zones in the province.

I thought you would be pleased I accepted your own quoted data..... but apparently not!:D

I still have some serious disagreements with that study, relating to the probable PF, and usage rates, but in fact that is really a side issue per the original subject.

Per the original question, there is NO advantage to installing your own capacitors at your own expense...... it will NOT save you anything on your bill. It will only enrich the makers of the device.

And so far, even the electric utilities have not seen fit to install that sort of distributed capacitance. In THEIR case, it COULD save them money, at least potentially, but still they have not done it, relying instead on block compensation "upstream" in the system.

If the folks with a real economic incentive to do it have not yet done it, there is even less reason for an individual to do it as what will be essentially a 'charitable contribution" to the powerco and to the makers of the device, not to mention to the electrician who installs it.