Estimating KWh electicity billing using clamp-on amp meter

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On 5/30/2011 7:34 AM, Home Guy wrote: ...

I did (or at least made a surmise) earlier...
I would presume that it is owing to the intense regulation being imposed on utilities that almost completely hamstrings them from being able to expand generation (and of also transmission) capacities or even to keep existing generation online.
In such a circumstance, anything they can do to provide incentives to users to level peak demand is a plus.
Or, the other possibility is that it is a condition placed on them by the State regulators. Certainly it will have been approved by same.
--
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dpb wrote:

How about a more simple explanation: Creative revenue enhancement?
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On 5/30/2011 9:07 AM, Home Guy wrote:

Even simpler: Rate commissions and consumer advocate groups combined w/ environmental and other regulations...
(30+yr commercial utility engineering experience)
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Whey don't they do peak and off-peak billing? That seems to make more sense and would be easier for the customers to adjust their consumption around,
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On 5/30/2011 1:34 PM, snipped-for-privacy@att.bizzzzzzzzzzzz wrote: ...

For residential, sure...this is commercial meter, though, not residential even though it is light commercial where it wouldn't make any significant difference in the (apparent) current use as given by OP.
OTOH, for "real" industrial large loads which is really the target, they generally use control algorithms to try to maintain as near level consumption as possible as well as maximize power factor. They do this by phased starting/stopping schedules for the really large gear, etc., etc., etc., as much as is feasible within other operational constraints...
One paper mill for which I did consulting had a very sophisticated startup sequence that relied on precise timing of motor-starting along the >1 mile length of the line. It took something otoo 45 minutes from the initial button press before the last set of rollers began to turn.
Another that used similar logic but that I never actually worked on was the rolling mill making Al can stock at the Alcoa facility in Alcoa, TN. It was a tower facility that had large feed rolls at one end and can stock collected on rollers at the other with about a half-mile of material going up and down in between in successive stages of the rolling process. I always thought it kinda kewl to watch the linear velocity increase from start to end--about 7-10X that at the entrance.
Electric arc furnaces at the Alcoa facility and other metal fab locations are another set of very large loads where anything to level load is a benefit financially and operationally as well.
--
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I was referring to the OP's comment about the 2000kWh limit before the utility uses demand billing, even on residential customers.

Understood. I was referring only to small, residential, customers.

You locate those *next* to power generation. ;-) It's the largest cost.
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On 5/30/2011 2:27 PM, snipped-for-privacy@att.bizzzzzzzzzzzz wrote: ...

...
Oh, sorry, missed that limited context intent.
No, I don't see it being particularly significant for residential customers for the most part other than, perhaps, the mcmansion-type w/ spa, pool and pool heaters, maybe the heated driveway thingie, etc., etc., etc., ... For the casual homeowner w/ a fridge and range and water heater, it's unlikely would make much difference. But, it would be simple enough to deal w/ things like the water heater and other loads not sharing "on" time.

Alcoa is where it is in large part owing to TVA in the WW II era as is Oak Ridge (gas diffusion plants and earlier magnetic separation) for the Manhattan Project. Rural at the time w/ plenty of water for power. Kingston Fossil was built subsequently for the expansion of the facilities during the '50s arms race.
While relatively close, the Al plant isn't right next door to generation facilities but the smelter is closer. It's kinda spooky driving along I40 when one of the loaded flatbeds passes at about 80-85 mph w/ that vat of hot Al on the way to the casting mill. There have been a couple of accidents where they've spilled one; it tends to leave crispy things all around... :(
--
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I would think it more important to get those things off "peak" times, where commercial users are the big users. I guess it depends on where the choke points are in the system.

I imagine it would.
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On 5/30/2011 3:21 PM, snipped-for-privacy@att.bizzzzzzzzzzzz wrote:
...

...
Indeed. I would guess the limitation for residential is in transmission and substations as growth continues to get more spread out from urban centers. Little of that is directed to or through the areas that would be serving the heavy industrial users so don't think it would make much difference for most utilities from that standpoint.
I could see that load leveling could, on a wide-enough scale, potentially allow one to forestall otherwise necessary retail market grid enhancements as a potential (altho distribution wasn't my primary area when doing work w/ the utilities; I was mostly generation-side I&C R&D for enhanced measurements during most of time w/ the fossil guys; prior to that while still in the nuke generation arena it was all very physics oriented and very little to do w/ anything more than remotely connected to actually generating power--only in that it took somebody to keep the reactors purring to boil the water in the SGs and deep in the bowels of the computational physics models used for those calculations are my thumb prints... :) )
--
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On 5/30/2011 1:34 PM, snipped-for-privacy@att.bizzzzzzzzzzzz wrote:

Peak and off-peak isn't all that easy with the old meters, but I thought that was one of the capabilities of the new "smart" meters. Also 'talking' to the occupant.
Demand is a common method for utilities to level the peaks for reasons that have been well covered. Around here the demand shows up as a penalty charge, not a kWh rate multiplier. For industrial metering "reactive power" (kVARh) metering is also pretty common - again a penalty charge. The penalties are high enough to provide a real incentive. Some installations with backup power run the backup to shave peaks.
If I had the questions Home Guy did I would talk to the utility. Leave the door unlocked? Why repeated numbers? Why wide variation? Estimates?
With a 400A service the current metering will use current transformers. There is likely a CT cabinet with a utility seal. Unless the disconnect is ahead of the CT cabinet I don't see a reason why the door can't be left unlocked. I don't see why it can't be unlocked anyway - the occupant has to have access to the disconnect.
--
bud--

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Demand metering requires a demand meter, too. Peak/off-peak metering has been done for decades without "smart meters", though usually with two meters. FWIG, almost all old-style mechanical meters will be gone in a short time.

That doesn't make any sense.

That makes even less sense.

Are you mixing VARS and demand?

He says no, but...

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On 5/30/2011 10:11 PM, snipped-for-privacy@att.bizzzzzzzzzzzz wrote:

I maybe should have said more.
A demand meter will show a "demand", which is kWh over a short time period, maybe 15 minutes. The maximum demand for the billing period is indicated and read, and the demand register is reset. I haven't looked at a utility rate structure, but basically the kWh demand is multiplied by a $number to give a penalty which is added to the bill. The higher the kWh demand the higher the penalty.
The penalty can be quite high and provides an incentive for the customer to use one of many "peak shaving" techniques.
Similarly the VAR meter (which for mechanical meters is a second meter) registers the reactive power 'used'. (This flows from the utility and back to the utility and is not actually used.) The kVARh in the billing period is multiplied by a $number to give a VAR penalty which is also added to the bill.
This penalty is high enough to promote using power factor correction caps, or other techniques, to improve the power factor.
The utility can, and does, correct the power factor. They can also improve the power factor caused by harmonics (I don't know if utilities do). They can't fix high demand.
--
bud--

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I understand all that, however...

...a fixed penalty vs. a rate penalty doesn't make sense, is what I meant.

Rolling blackouts. ;-)
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You have all this time to fine one counterexample and none to INVESTIGATE YOUR OWN DAMNED BILL? What a complete moron!
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" snipped-for-privacy@att.bizzzzzzzzzzzz" wrote:

Obviously you didn't.

^^^^^^^^^^^^^^^^^^^^^

Yes, I have the time to entertain tangents to the thread I started, which includes showing what a moron you are when you don't read what others have posted.
Why do you refuse to admit you were wrong? Diversion isin't an answer.
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But no time to research your own damned problem.

Of course you're too stupid to figure out that I have read the whole silly thread. You really are an ass.

I said you fond ONE counterexample, dummy. Why do you snip context? The fact is that you aren't looking for an answer, troll.
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In wrote:

...
Your quote is not a cut/paste of the actual words, which is too bad; looks like you paraphrased it to suit yourself or t was somehow not the rght one as it doesn't mention residential/company connections and several other things. That one very gross spelling error hurts you too; it stands out like a sore thumb.
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wrote:

Sure you can. I do it all the time. Some can't be edited (depending on how it was created) or cut but just because it's a PDF doesn't mean you can't cut-n-paste from it. You can highlight, underscore, add notes, and do a *lot* of things to a PDF.
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@Home Guy:
You are too focused on the total billed number of kWh to see why a demand meter is used for electrical services with a main disconnect rated over a certain amperage...
A customer with a steady draw (demand) of 2.7 KW over 30 days to end up being billed for 2,000 kWh over the course of a billing period is *MUCH* easier for a power company to serve than a customer whose draw is 500 KW a couple of times during the same billing period and winds up with the same 2,000 kWh of use...
To serve the second customer whose demand is erratic and might come at a time when the local power grid is overloaded requires the power company to provide beefier service lines in that area and have the capacity to accommodate that erratic load without tripping safety devices in the power grid or browning out other customers...
You just don't seem to understand that the greater the amount of power a customer needs to use at the same time (peak demand) is more important than the total of the kWh that customer is billed for during any given period... Whether you use 1 KW for 2,000 hours or 2,000 KW for 1 hour makes a difference in how the power company serves you as far as equipment and capacities...
Again whether or not you have a demand meter depends on the purpose of the occupancy and the amperage rating of the main disconnect... A home with a 100 or 200 amp main service would usually not have a demand meter, but a home with a 1,200 amp main disconnect very well might have a demand meter installed...
~~ Evan
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@Home Guy:
Just because you are only using 2,000 kWh a month in your building is meaningless... Your building is equipped with service entrance equipment which could supply it with far more power if you were doing things that needed it...
You clearly do not possess enough information or knowledge to be of any use describing what service equipment you have installed in your building... You say you are only using 120/208 3-phase power, well you have no idea what your building is being supplied with, it could have a 400-amp 277/480 3-phase supply which would mean that you are only using one or two sub panels fed by an on premises transformer...
It is *NOT* the power companies' fault that your building's electrical facilities are GROSSLY over sized for the current occupancy that you are using it for... But that is nothing the power company nor the PUC will ever worry about -- as long as your building is equipped with the service entrance equipment which has 400-amp capacity you will never be able to get rid of the "demand meter" even if your actual power usage is very low at approximately 2,000 kWh a month...
If it is _that_ important to you to no longer have a "demand meter" then you can hire an electrician to remove the old electrical service equipment and install a smaller service in-line with what your actual power consumption is, but until you have all the old power panels and service head removed from your building, the power company WILL NOT install a non-demand meter for your building...
You can ask RBM how much that would cost, depending on the sq. ft. of the building it can be expensive...
~~ Evan
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