Power Factor verses Efficiency

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weressl said:
kwired: I don't see kVAr or 'time' associated with it, so don't really know what you're trying to say. Sahib has claimed kVA as quantity, which it is not. The bill he has presented does not identify the what is being billed, just identified as units. Lets presume that to be kWhr's. Line 1 through 6 and then it summarizes it in line 7 as Total energy charges. Lines 1-5 uses the word 'consumption'. Then in line 8 it indicates demand charges for kVA and in line 8 summarizes Demand and Energy charges, clearly indicating that Demand itself is SEPARATE form Energy.

As I explained earlier Utility Companies use demand charges as a transmission/conversion eqipment surcharge, because they have to size their equipment to deliver kVA and not kW. They measure the highest monthly averaged peak (demand) to determine what this particular customer's power need required for that month and apply the demand charge accordingly.
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I should have looked at the bill again before posting, you are correct, there is no power factor charge on that bill.
 
weressl said:
Can you 'consume' kW?

How about kWh?

Do you see where the time 'element' is?
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Thanks, Lazlo, for your explanation. But still it is not acceptable, because both KVAR and KVARh can not be consumed even if KVARh meets your criterion. So better concede to my argument at post #71 with time element implied in it. :)

weressl said:
line 8 it indicates demand charges for kVA and in line 8 summarizes Demand and Energy charges, clearly indicating that Demand itself is SEPARATE form Energy.
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Yes. Demand charges are separate from energy charge, because it is power charges for power utilized during the maximum demand period.
 
Typo

Typo

mivey said:
We casually speak of reactive energy flowing back and forth from the load to the source in half cycles but that is not exactly what happens except on loads with no resistance (which don't exist). Consider the resistor-inductor load. As the magnetic field charges, the source has to deliver the real energy (Wh) plus the energy to charge the inductor (varh).

As the inductor discharges, the real energy needed by the load is supplied by both the source and the energy from the collapsing magnetic field (when VA(t) is positive and greater than W(t) in the plot). As the field discharges, it supplies all of its released energy to the real load (when VA(t) is positive and less than W(t) in the plot). Over time, the real energy needed is less that what is being released from the magnetic field and then this excess field energy is returned to the source (when VA(t) is negative in the plot).

VA-W-var.jpg
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There is a typo. I pasted a note in the wrong paragraph. This should have read:

mivey said:
...
As the magnetic field charges, the source has to deliver the real energy (Wh) plus the energy to charge the inductor (varh), (when VA(t) is positive and greater than W(t) in the plot).

As the inductor discharges, the real energy needed by the load is supplied by both the source and the energy from the collapsing magnetic field. As the field discharges, ...
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Sahib said:
Thanks, Lazlo, for your explanation. But still it is not acceptable, because both KVAR and KVARh can not be consumed even if KVARh meets your criterion. So better concede to my argument at post #71 with time element implied in it. :)


Yes. Demand charges are separate from energy charge, because it is power charges for power utilized during the maximum demand period.
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Suite yourself Humpty-Dumpty.
 
Sahib said:
Thanks, Lazlo, for your explanation. But still it is not acceptable, because both KVAR and KVARh can not be consumed even if KVARh meets your criterion. So better concede to my argument at post #71 with time element implied in it. :)


Yes. Demand charges are separate from energy charge, because it is power charges for power utilized during the maximum demand period.
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What has any of this to do with the OP's question of if power factor and efficiency are the same thing (they aren't)?
 
ggunn said:
What has any of this to do with the OP's question of if power factor and efficiency are the same thing (they aren't)?
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Good question.
The OP had a doubt in his mind whether power factor and efficiency are the same thing. Other members clearly demonstrated that they are not same things. I tried to show that efficiency (as it has various definitions) and power factor may be equivalent in some application (such as efficiency of utilization KVA supplied by a utility to a consumer from the utility's standpoint.) One justification for my doing so comes from Einstein. He showed the equivalence between mass and energy, even though they are different concepts.
 
Sahib said:
Good question.
The OP had a doubt in his mind whether power factor and efficiency are the same thing. Other members clearly demonstrated that they are not same things.
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Exactly. EOS right there.
So, please cease and desist from your your continued obfuscation and confusion. The OP was satisfied with the simple explanation given in post #2.
 
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Lazlo:
It is not correct to say there is no time element in KW. Because KW is energy consumed per unit time.
 
Sahib said:
Lazlo:
It is not correct to say there is no time element in KW. Because KW is energy consumed per unit time.
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Nonsense.
kW is power, not energy. It is an instantaneous value.
Energy is power times time. Joules. Ws. not W/s.
 
Besoeker said:
Nonsense.
kW is power, not energy. It is an instantaneous value.
Energy is power times time. Joules. Ws. not W/s.
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I am afraid there is a great misunderstanding at elementary level on your part. Because as far as I know power is measured as an average quantity and not as an instantaneous quantity for energy consumption calculation purposes in AC circuits.
 
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Besoeker said:
One volt and one amp occurring at the same instant is one watt at that instant.
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Yes, that is for energy calculation for DC circuits and not for energy calculation in AC circuits. Here AC circuit is discussed. Also KW in AC circuits denote average power and not instantaneous power.
 
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don't get confused with average, RMS, other elements of an AC wave form. Any averaging (really RMs) is to get the effective DC equivalent and not an average over time.

When POCO bills us for energy it is in kilowatt-hours, there is a time element involved.
 
Sahib said:
Yes, that is for energy calculation for DC circuits and not for energy calculation in AC circuits. Here AC circuit is discussed.
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It makes no difference.
One volt and one amp occurring at the same instant is one watt at that instant.

Here's a picture to help you understand:

 
kwired said:
don't get confused with average, RMS, other elements of an AC wave form. Any averaging (really RMs) is to get the effective DC equivalent and not an average over time.

When POCO bills us for energy it is in kilowatt-hours, there is a time element involved.
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kwirred:
RMS value apply to AC voltage and current. Their product ie power for a purely resistive load is not a RMS quantity but an average quantity. You may find it by taking products of instantaneous values of AC voltage and current for a resistive load and finding the average of them. The result will be the power through the resistive load.
 
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