Why KWHr on meters instead of KVAHr? 1

[AggiesNM]

Loads can be resistive, inductive or capacitive. However, when we look at the meters it only indicates energy cosumed in KWHr. Are we ignoring the reactive power in billing?

 

[jraef]

For other than residential customers, kVAR are usually metered separately and used to calculate a penalty for having poor power factor. Residential services are ignored for the most part because they represent a very small return for the investment of metering for it.

"If I had eight hours to chop down a tree, I'd spend six sharpening my axe." -- Abraham Lincoln
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[Skogsgurra]

It depends. Some don't care, some care a lot. Historically, the kWh was what consumed coal and what represented real work. So kWh meters were, and are, dominant. Later, as distance between generators and consumers grew, the transmission costs and the size of transformers and switchgear proved to be more dependent on current, so utilities started to worry about reactive power and power factor. Nowadays, there is sometimes a price tag attached to kvar and sometimes kVA.

Gunnar Englund

http://www.gke.org

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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...

 

[AggiesNM]

I was thinking 70% of the loads on the system were inductive which would correspond to significant KVAR requirement. As for the industrial loads I was thinking metering pertained to KWHr and Demand Metering.

I am guessing a poor powerfactor load equates to high current consumption which equates to higher bills.

 

[wareagle]

Utilities that I have dealt with had to rates. If the demand was 800 kw of less the demand billing was based on KW. If the demand was over 800 kw the billing was based on KVA. They billed KWH's + and KVA demand of about $5/KVA. So it was an advantage to keep the PF high and stay in the KW range.

 

[waross]

Historically in North America many utilities metered KWHrs and KVARHrs and calculated the average monthly power factor. A penalty of 0.9 - PF was then applied to the KWHr consumption.
eg: If the average power factor for a month was 755 then a penalty of 0.9 - 0.75 or 15% would be applied to the KWHr consumption charges.
Now there are much more punative formulas and some countries charge for any amount of KVARHr consumption, either leading or lagging.
As has been mentioned, KVAR metering and PF penalties were applied to large commercial and industrial users.

Bill
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"Why not the best?"
Jimmy Carter

 

[jghrist]

It takes fuel to generate kWh, but not to generate kvarh.

It does, of course take money to build lines and equipment to carry kvar and fuel to generate the kWh from losses caused by kvar.

 

[LSpark]

In the UK kVARhs are ingnored for domestic customers but a correction is usually made for power factor for industrial customers, so it isn't ignored. The power stations are a bit different and are usually given a lump sum payment to provide reactive power to National Grids instruction sometimes with a small payment per MVARh.