My electric billing rate is based on my time of day usage and my monthly peak demand.

My electric meter is an older style that uses dials to indicate power usage. It also has a digital display that doesn't display anything meaningful.

It appears that there is a port on the front of the glass cover where the meter reader connects an external device to extract data from my meter.

My question is how does the meter record peak demand? Is it an instantaneous peak demand or an average peak demand over some time interval?

My bill shows the time and date of both on peak and off peak maximum usage time, but they are always shown either on the hour, 15 min after, 30 min after or 45 min. after. This would seem to indicated some type of 15 min. averaging.

The electric company is Progress Energy, and I'm located near Pinehurst, NC.

If you look at Progress Energy website, I did a search for demand metering:


Search Results - Progress Energy

You can look for your situation for their explanation of billing.

This may or may not help you.

Basically, demand metering looks for the highest amount of power used in any 15 minute period during a billing cycle. This sets your Demand KW, and will be multiplied by the demand multiplier determined by the utility.

The most popular billing for electricity is KiloWattHour, the amount of power used by time. This covers the cost of producing the energy.

Demand KW ling covers the cost of the infrastructure of delivering the power.

Users can keep their demand KW down by insuring large loads are not turned on at once in the same 15 minute period. Design of control or process is needed to keep large loads from starting at the same time.


This is a popular problem with new large industrial plants or commercial buildings, usually during startup, commissioning, and testing. Technicians don't think of how a plant gets billed for energy, they just begin starting and stopping large loads during a startup of a plant.

Loads that normally would not all start at once do get started all at the same time, and new plants have gotten huge bills due to demand KW billing all becase of the startup of the plant.

Usually a call to the utility to explain what happened gets the bill reduced, and the plant gets a good awareness of how not to start their loads.

Hope this helps.

MTDC Pubs, Saving Money by Understanding Demand Charges on Your Electric Bill, 0071 2373

Dear Sir,

Do power factor corrector lower the demand charges and the electric billing. And how do it help.

Best regards,
Richard

Lowering PF does not lower demand, only lowers electric bill if your billed for low PF.

Correcting low PF will provide additional capacity on the system.