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Bud--

On 5/30/2011 10:11 PM, zzzzzzzzzz wrote:
On Mon, 30 May 2011 20:34:10 -0500, wrote:

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.

That doesn't make any sense.

For industrial metering
"reactive power" (kVARh) metering is also pretty common - again a
penalty charge.

That makes even less sense.

The penalties are high enough to provide a real
incentive. Some installations with backup power run the backup to shave
peaks.

Are you mixing VARS and demand?

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--

[email protected]

On Wed, 01 Jun 2011 11:11:56 -0500, bud-- wrote:

On 5/30/2011 10:11 PM, zzzzzzzzzz wrote:
On Mon, 30 May 2011 20:34:10 -0500, wrote:

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.

That doesn't make any sense.

For industrial metering
"reactive power" (kVARh) metering is also pretty common - again a
penalty charge.

That makes even less sense.

The penalties are high enough to provide a real
incentive. Some installations with backup power run the backup to shave
peaks.

Are you mixing VARS and demand?

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.

I understand all that, however...

This penalty is high enough to promote using power factor correction
caps, or other techniques, to improve the power factor.

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

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.

Rolling blackouts. ;-)

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