Below is a glossary of common terms you may run into when performing utility bill accounting. If we are missing a term, or definition, please let us know, and we will add your word or term to the list.
Balance Point
The cooling balance point is the temperature at which the building starts cooling. The heating balance point is the temperature at which the building starts heating. This is a crude but effective definition. CDDs and HDDs are calculated using the balance point. The Cooling Balance Point need not necessarily be the same as the Heating Balance Point.
Base Load Level (on utility bills)
The base load level is the lowest load level measure during a company’s annual or daily cycle.
Base Load (the concept)
The energy used that has nothing to do with heating or cooling the building. Baseload energy is usually composed of lights and computers and 24/7 fans and pumps.
Base Year
Base Year means two different things to two types of Metrix users. Base Year represents the year to which you are comparing current year’s data. If you are using Metrix to calculate savings due to energy projects, then base year represents the period of time before the ECMs were installed. If you are using Metrix to track your bills in general, then base year represents some year in the past that was selected for comparison to current year’s data.
Baseline
Baseline is a confusing term because it appears to have many meanings in the energy industry. For this discussion, “Baseline” represents “how much energy would have been used during the Base Year period, given today’s conditions”, where “today’s conditions”, for the most part, means weather and number of billing days. Different utility accounting systems have different meanings for Baseline, unfortunately.
Baseline Equation
The Fit Line, which was created in Metrix when a regression was performed, has an equation, which is called the “Fit Line Equation.” The Baseline Equation is the same as the “Fit Line Equation, except it can also have Baseline adjustments tacked onto it.
Baseline Equation = Fit Line Equation +/- Baseline Adjustments
Billed Demand
Billed Demand is not the same as Metered Demand. Metered Demand is the highest kW value measured over a 15 minute interval (or some variation of this). Utilities often will charge their customers, not on Metered Demand (what they used), but rather on Billed Demand. Billed Demand is calculated for each billing period based upon several factors which can include.
Billing Period
The billing period is the time period for which a customer has been billed. The Billing Period stretches from the bill’s start date to the bill’s end date, and these dates typically reflect when the meter was read.
BTU (British Thermal Unit)
The BTU is the standard unit of measurement for heat. A BTU is defined as the amount of energy needed to raise the temperature of one pound of water 1 degree Fahrenheit from 58.5 to 59.5 degrees under standard pressure. One kWh has 3413 Btus.
CCF
An abbreviation for One Hundred Cubic Feet. CCF are used to measure consumption of water or natural gas. Sometimes a CCF of water is called a “Unit.” A CCF of water is about 748 gallons.
CDD
See Cooling Degree Day
Commodity Charge (aka, Energy Charge)
Gas bills sometimes are broken up into commodity charges and transportation charges. The Commodity Charge is the charge associated with the amount of energy purchased from the supplier.
CoGeneration Facility
Privately-owned electric generation plant that produces electricity and heat by burning fossile fuels.
Constant
Meters do not directly measure energy or power, but rather measure some other factor which is then multiplied by a constant in order to determine the amount of energy or power used.
Consumption
The measured amount of energy or water used during a given period. This is different from demand, which can be thought of as the greatest rate at which the energy or water is delivered at any one time during the billing period. In terms of electricity
Consumption Meter
Some electricity meters measure consumption only, and not demand. These meters are called consumption meters.
Contract Carrier
A contract carrier is an oil or gas pipeline company that sells its services to the customer on a contractual basis.
Contract Demand
Some electricity rates require the utility to establish a Contract Demand for each individual meter. The Contract Demand is the capacity in kW that the utility has judged the customer might use at peak conditions. Customers are often billed for contract demand indirectly, such as, billed kW = the maximum of 50% of contract demand or current month’s metered demand.
Cooling Balance Point
The cooling balance point is the temperature at which the building starts cooling. This is a crude but effective definition. CDDs are calculated using the cooling balance point.
Cooling Degree Day (CDD)
CDDs are a way to measure how much cooling is required in some period of time. A large number of CDDs signifies that the building required a large amount of cooling. Zero CDDs signifies that the building did not require any cooling.
In case you are interested, CDDs for each day are calculated as follows:
CDD = (TMean -TBalance Point ) * Nday+
Where TMean is the average of the high and low temperature for a day, and Nday = 1, and CDD must always be positive.
For Utility Bill Analysis, CDDs are calculated separately for each day and then summed together into billing periods.
Cost Avoidance
Almost the same as Cost Savings, but different. Cost Avoidance is the difference between what how much utility usage would have cost had no ECMs been installed, and how much utility usage did cost now that ECMs have been installed.
Customer Charge
Many rates have a monthly or daily charge that customers pay, whether they use energy or not. Different utilities will call it customer charge, monthly charge, facilities charge, service charge, etc.
Cubic Foot
A Cubic Foot is the volume of gas required to fill one cubic foot of space at 60 degrees Fahrenheit at sea level (14.73 psi)
Deduct Meter
A Deduct Meter is a special in-line water meter used to measure water consumption that does not enter the sewer system and for which an adjustment is given in calculating sewer charges.
Demand Charges (Therms)
A charge for service that allows a customer to receive an unlimited (or specified) supply or volume of gas at any time throughout the year.
Demand (Electric)
The amount of electricity needed at any one moment in time (moreso, any 15 or 30 minute period of time) in order to meet a meter’s energy needs. Suppose you drove 100 mph for � hour. You drove 50 miles at 100 mph. You can equate the concept of demand to speed. In this case, mph is like demand, and miles driven is like energy. Remember
ECM
Energy Conservation Measure. This term is widely used to represent any energy efficiency project that will reduce energy expenditures. Similar acronyms include FIM (facility improvement measure), ECO (energy conservation opportunity).
ECO
Energy Conservation Opportunity. This term is widely used to represent any energy efficiency project that will reduce energy expenditures. Similar acronyms include FIM (facility improvement measure), ECM (energy conservation measure).
Energy Accounting
The process of monitoring and recording the consumption of energy and demand. Energy Accounting is a great first step in setting up an energy savings program for a facility. Once you understand how much energy you are using and where it is being used, you can determine where you can most easily save energy.
Energy Avoidance
Almost the same as Energy Savings, but different. Energy Avoidance is the difference between what how much energy would have been used had no ECMs been installed, and how much energy was used now that ECMs have been installed. Not many energy analysts use this term for some reason.
Equipment Rental
Equipment, such as a water heater or a chiller, that is rented from a utility company, usually on a monthly basis.
Estimated Bill
Sometimes utilities cannot read a customer’s meter due to factors such as employee illness, equipment malfunction, etc. When this occurs, the utility may choose to charge the customer for an “estimated bill.” The estimated bill is determined based upon past usage history. In most cases the Estimated Bill is corrected the following month. Some gas utilities will send their customers monthly bills with Estimated charges for the past month, and the Actual charges for the month before that. Since the customer already paid the Estimated Bill for the prior month, the Actual Bill is used to “true up” the account by charging or crediting the customer for the overage or underage that the customer did or did not use for the estimated bill period.
Fit Line
Fit Line is another term for “best-fit” line, or the line that comes closest to all the points in the Metrix tuning graph.
Fit Line Equation
Every line can be defined by an equation, such as y = mx + b. The Fit Line Equation is the equation for the Fit Line in Metrix.
FIM
Facility Improvement Measure. This term is widely used to represent any energy efficiency project that will reduce expenditures associated with running the facility. This often means reducing energy usage, but could mean reducing cost of toilet paper or garbage service. Similar acronyms include ECM (energy conservation measure), ECO (energy conservation opportunity).
Firm Service
Customers usually pay more for gas or electricity that is sold with a guarantee (Firm Service) for delivery. The opposite is Non-Firm service for electricity or interruptible service for gas. In times of shortage, Non-Firm customers may not receive energy. This happened to many non-firm customers during California’s notorious summer of 2001.
Fuel Adjustment
The additional charges or credits that some utility companies include in their bills to offset the variance in the price of the fuel used to generate electricity. This adjustment is typically represented as cents per kWh. It is not uncommon for fuel adjustments to be negative.
Gas Cost Recovery
Most utility companies define Gas Cost Recovery as “the average cost per thousand cubic feet of gas purchased or produced for sale to the customers of the utility.” In other words, it is the difference between what the utility paid for the gas and what they sold it to their customers for.
HDD
See Heating Degree Day
Heating Balance Point
The heating balance point is the temperature at which the building starts heating. This is a crude but effective definition. HDDs are calculated using the heating balance point.
Heating Degree Day (HDD)
HDDs are a way to measure how much heating is required in some period of time. A large number of HDDs signifies that the building required a large amount of heating. Zero HDDs signifies that the building did not require any heating. In case you are interested, HDDs for each day are calculated as follows:
HDD = (TBalance Point – TMean) * Nday+
Where TMean is the average of the high and low temperature for a day, and Nday = 1, and HDD must always be positive.
For Utility Bill Analysis, HDDs are calculated separately for each day and then summed together into billing periods.
Horsepower
A horsepower is unit of measurement used to determine the capacity of a mechanism to do work. One Horsepower is the equivalent of raising 33,000 pounds one foot in one minute. 1 horsepower equals 746 Watts of electricity at 100% efficiency.
Interruptible Service
Gas that is sold without any form of guarantee of delivery. Utilities are able to curtail delivery to their interruptible customers to allow for seasonal or shortfall adjustments. Gas billed to interruptible costs less than that sold on a Firm sales basis.
Irrigation Meter
An Irrigation Meter is a special in-line water meter used to measure water used for irrigation and thus for reducing water consumption assigned to sewer charges.
Kilowatt
1,000 Watts, or 3413 Btus
kVA
Kilovolt Amperes, often referred to as the Total Power, it is the sum of working power (KW), and the non-working power (KVAR). Non-working power is the current that is needed to electrify the system to reduce resistance and line loss.
kW
kiloWatt. The measure of demand or the rate at which electricity is used. Remember
kWh
kiloWatt hour. The measurement of consumption of electricity for a given time period. One kWh equals one kW of electricity used for one hour. Remember
Late Charge
A fixed or percentage amount charged by the utility company when a customer fails to meet the utility’s predetermined payment deadline.
LF
See Load Factor
Load Factor (Electricity)
Load Factor is a way to measure how the facility is using energy. Meters with high load factors represent meters that use nearly the same amount of energy all hours of the day. Meters with low load factors have a very high usage during peak times, and low usage during off peak times. Load Factor is calculated as follows:
LF = kWh / (kW * # Days * 24 hrs/Day)
MCF
One thousand cubic feet, natural gas and perhaps water can be measured in billed in MCF.One MCF equals the heating value of 1,000,000 Btu (MMBtu).
Meter
A device used for measuring consumption or demand.
Mid Peak
Mid Peak is another name for Park Peak, or Shoulder, which are TOU Periods. A Mid Peak period might be from 8am to 10am and from 4pm to 6pm on weekdays.
MMBTU
One Million Btu.
Multiplier
Often referred to as Meter Constant. See Constant.
NonFirm Service
Some utilities allow customers to receive Non-Firm service, as opposed to Firm service. Non-Firm Service means that the utility does not guarantee service all the time, and therefore is less expensive. However, in times of power shortages, non-firm customers may not receive any power at all, as happened to many non-firm customers in California during the notorious summer of 2001.
Non-Temperature Sensitive Usage
The energy used that is not related to weather. This would include computers, lights, pumps, kitchen equipment, etc.
Off-Peak
A time period determined by a utility company to reflect the time of day when demand is at its minimum. Usually Off-Peak represents evenings, nights and weekends.
On-Peak
A time period determined by a utility company to reflect the time of day when demand is at its maximum. Usually On-Peak represents weekday hours.
Power Factor
A method of determining the quality of energy being used at your facility. Facilities using large amounts of uncompensated fluorescent lighting or ac induction motors often have lower power factors. Power factors are measured in percentage, and customers are often billed if the power factor drops below a certain threshold, like 85% (and sometimes credited for higher power factors). Power Factor problems can be fixed using capacitors.
Pressure Factor
A billing factor that may be used to calculate the price of gas delivered to the customer at higher pressure.
Primary Metering
See Primary Service
Primary Service (aka Primary Power)
Primary Service is electrical service that is metered before the transformer (which will “step down” the voltage to a usable level). Utility customers who receive Primary Power, usually own or rent their own transformers, rather than have the utility provide them. When electrical service is provided through this type of metering, the meter is measuring raw power rather than transformed power. Electrical power, in order to be useful, must be converted to the correct voltage for the intended application. This is accomplished through transformers. When this type of conversion occurs, there is a slight loss of electrical energy through heat that is a by-product of the conversion process or transformation. Primary Electrical service is less expensive than Secondary Service, which is more common.
Private Carrier
An interstate gas pipeline company that owns the gas it carries.
PSC
Public Service Commission
PSI
Pound per Square Inch. This is a measurement of pressure.
PUC
Public Utility Commission
Ratchet
Some utilities charge customers for demand based upon not just the current billing period’s metered demand (kW), but they also take into account previous months metered demand. A typical ratchet may read like
Rate Schedule
A set of tariffs that present the prices to be charged to the customers of the utility company for services or supply of commodity. It also lists the responsibilities of the utility company.
Read Date
Calendar date on which meters were read and recorded.
Regression
Regression is a statistical operation, which graphically can be described as drawing a straight trend line (or “best-fit” line) as close to all the points in a graph as possible. The “best-fit” line, or regression, then is said to represent the points in the graph. Also called Tuning.
Rider
A variant to a tariff or rate schedule. Riders tend to make rates very confusing because bills don’t always tell you that a rider is being applied. As a result, sometimes you cannot calculate your rate by hand because you don’t know all the charges being applied.
Savings
The reduction in the quantity (of energy or water) that can be discerned from utility bills. This is similar, but not the same as the term, “usage avoidance”, which some people use. What makes it more confusing, is that some people use the word “savings” to mean “cost avoidance”, “energy avoidance” or the reduction in usage or cost that can be determined from utility bills.
Secondary Service
(Secondary Metering, Secondary Power) Electrical service that is metered after the transformer. Primary Service is metered upstream of the transformer (or on the primary side).
Shoulder
Shoulder is another name for Park Peak, or Mid Peak, which are TOU Periods. A shoulder period might be from 8am to 10am and from 4pm to 6pm on weekdays.
Solid Waste
Garbage
Super Off Peak
A few rates have a Super Off Peak Time of Use (TOU) Period. This is a fourth TOU period that would probably represent night hours and weekends.
Surcharge
A special charge, tax or fee billed to a customer that is not a standard part of a utility’s tariff.
Storm Water
Water originating from rain or other outside sources that does not enter the sewer.
Tariff
A document or schedule filed by a utility company with its federal or state regulatory agencies that presents the rates charged to its customers for the services or commodity delivered.
Temperature Sensitive Usage
The energy used that is related to weather. This would mean air-conditioning equipment, chillers, cooling towers, boilers, hot water pumps, etc.
Therm
100,000 BTUs
Time of Use
Some rates bill their customers based upon the time of day the energy was used. For example, a rate may have On Peak, and Off Peak Charges. On Peak would represent the period of time in which energy is most in demand (and most expensive), and Off Peak would represent the period of time in which energy is least in demand (and least expensive). For example, in California, On Peak would be during week days, and Off Peak would be week day nights and weekends. Some TOU rates have 4 Time of Use periods.
TOU
Time of Use
Transformer
Power is transferred along transmission lines at very high voltage. Transformers are then used to “step down” or reduce the voltage to a usable voltage level.
Tuning
Tuning is the process of performing a regression (and is the term used in Metrix). A Tuning Graph is a graph that shows the points and the “best-fit” line. Tuning and Regressing are synonyms (as verbs). Tuning and Regression are synonyms (as nouns).
Unit
Some water companies charge for water in “units”, which is the same as a CCF, and represents about 748 gallons.
Watt
A unit of measurement of electrical consumption. (The power used when one ampere of direct current (DC) flows through a resistance of one Ohm.)