Reference
The terms on a commercial utility bill
Every definition here carries a real number from a filed tariff, because the abstract version is not much use. Knowing that kVA means apparent power matters less than knowing CenterPoint charges $4.893378 for each one.
Figures read from tariffs filed with the Public Utilities Commission of Ohio and the Public Utility Commission of Texas. Reviewed at the start of each month.
Ccf
Also: hundred cubic feet
A hundred cubic feet of natural gas, and the unit most US gas bills are denominated in. It measures volume rather than energy content, which is why a bill also carries a heat-content adjustment.
Columbia Gas of Ohio's Standard Choice Offer is $0.4975 per Ccf.
Columbia Gas rates, and how the SCO is setCcf vs Mcf
An Mcf is a thousand cubic feet — ten Ccf. Suppliers quote in both, and comparing a price per Ccf against a price per Mcf makes one look ten times cheaper than it is.
Columbia Gas at $0.4975 per Ccf is $4.975 per Mcf. The same rate.
Comparing Ohio gas supplierskVA
Also: kilovolt-ampere
Apparent power: the total a utility's system has to carry to serve you, as opposed to kW, which is the portion your equipment converts into useful work. The gap between them is reactive power, drawn by motors, compressors and transformers.
CenterPoint bills commercial demand in kVA at $4.893378 per billing kVA. Oncor, in the same state, bills kW instead.
Why CenterPoint bills in kVAkVA vs kW
kW is real power — what does work. kVA is apparent power — what the grid must carry. They are equal only at a power factor of 1.0. Below that, kVA is always the larger number, and a utility that bills kVA is billing the larger number.
80 kW of useful load at a 0.80 power factor is billed as 100 kVA.
What the unit costs on a Houston billPower factor
The ratio of real power to apparent power — how much of the electricity drawn is actually converted into work. At 1.0 nothing is wasted. Motors, compressors and older lighting ballasts pull it down.
On CenterPoint, 80 kW at 0.80 power factor costs about $97.87 a month more than the same work at unity — roughly $1174 a year, for no additional output.
Power factor, worked from the tariffPeak demand
Also: billing demand
The highest rate of power drawn during a billing period, measured over an interval — usually 15 or 30 minutes — rather than at an instant. It is billed per kW, separately from the kilowatt-hours consumed.
Billed demand is often higher than metered demand. Ohio Edison's Rate GS bills a minimum of 5 kW whatever the meter recorded.
How demand charges workLoad factor
Consumption divided by what you would have used running at your peak the whole period. A steady operation scores high; one with a few busy hours scores low. It measures how evenly power is used, not how much.
Oncor bands its distribution charge by annual load factor, from $6.931363 per kW at 26% and above to $9.831092 below 10% — a 42% spread for the same peak.
The load-factor bands, and the ratchetCoincident peak
Also: 4CP, NCP
Demand measured at the moment the whole grid peaked, rather than when you did. NCP is your own non-coincident peak; 4CP averages your draw during the four intervals when the regional system peaked — windows nobody is told about in advance.
On Oncor, establishing 700 kW in any previous billing month moves an account onto 4CP billing for the transmission rider, permanently.
Where 4CP appears on an Oncor billDemand ratchet
A rule that keeps billing you for a past peak. Billing demand becomes the greater of this month's peak or a set percentage of your highest peak over a preceding window, so one busy month is charged for many.
Oncor applies an 80% ratchet over eleven months above 25% load factor. CenterPoint applies none — its billing kVA is simply the current month's peak.
The two Texas utilities comparedInterval data recorder
Also: IDR meter
A meter that records consumption in short intervals rather than a single monthly total, which is what makes demand and coincident-peak billing possible. Which meter you are billed as having changes the fixed charges.
CenterPoint's fixed charges above 10 kVA are $13.41 a month on a standard meter and $151.41 on an IDR one — and the IDR rates apply to anyone who has ever established 700 kVA, fitted or not.
What the meter decidesRate schedule
Also: tariff
The document a utility files with its state commission setting out what it charges and who qualifies. Eligibility usually turns on peak demand and service voltage, and a business is assigned to one rather than choosing it.
Schedules carry rules that never appear on a bill. Duke's Rate DS recalculates billing demand as monthly kWh divided by 71 when load factor drops.
What a bill audit checksDelivery charge
Also: TDU, TDSP, distribution charge
What the utility bills to carry electricity over its poles, wires and meters, as opposed to the supply charge that pays for the electricity itself. It is regulated, set by the utility, and no competitive supplier can change it.
On many commercial accounts it is the larger half of the bill, because it carries the demand charges and the fixed monthly charges while supply is purely per kWh.
The delivery half, explained