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Glossary

Electricity terms and their definitions.

Energy, expressed in kilowatthours (kWh), is the power used by electrical equipment over a given period of time. It is calculated as power (wattage), expressed in watts (W), multiplied by the time during which it is used, expressed in hours (h).

energy (kWh) =  power (W) x time used (h) 1,000

The load factor (LF) is the relationship between the real power consumed (kWh) and the maximum power that can be used in a given period, as a function of the use of the maximum power demand. It is used to evaluate the use of maximum power demand for a given billing period

LF =  consumption during period (kWh) maximum power demand x number of hours in period x 100

The power factor (PF) is the ratio between real power and apparent power.

PF =  real power apparent power x 100

Current, expressed in amperes (A), is the number of electrons carried by a conductor in one second. It is a function of voltage, expressed in volts (V), and resistance, expressed in ohms (Ω).

current (A) =  voltage (V) resistance (Ω)

The measurement of energy use by a separate meter for each residential or commercial unit in a building.

The measurement of energy use by a single meter instead of separate meters for an entire multiunit commercial or residential building. The building owner is responsible for dividing the costs between the occupants.

A factor applied to the fixed charge and number of kilowatts used to determine the billing demand threshold at rates DM, DT and DN, as well as the number of kilowatthours to which the first tier of rates DM and DN applies.

The winter period runs from December 1 through March 31 of the next year, inclusive.

The summer period runs from April 1 through November 30, inclusive.

Power demand, expressed in kilowatts (kW), is the total amount of electricity required by equipment at a given time. In more technical terms, it is the combined effect of voltage, expressed in volts (V), and current, expressed in amperes (A).

power (kW) =  voltage (V) x current (A) 1,000

Apparent power, expressed in kilovoltamperes (kVA), is the maximum quantity of electricity Hydro-Québec must provide to the customer. When it is used, it is broken down into real power (kW), which runs devices, and reactive power (kVAR), which results in the creation of magnetic fields.

This is the minimum amount of power you pay for. The threshold is set so that you pay a monthly amount that represents your share of the costs Hydro-Québec incurs to meet your power needs at all times.

Minimum billing demand is determined by the conditions of each rate, as indicated in the Electricity Rates. It is automatically based on your previous winter consumption or your contract power at the applicable rate.

The maximum power for a given contract that you may not exceed without Hydro-Québec's approval.

Real power, expressed in kilowatts (kW), is the power actually used to run equipment such as motors, lights or a heating system.

The contract power, chosen by Rate L customers, represents the minimum power that the Rate L customer has to pay and the amount of power that Hydro-Québec must be ready to supply at any time in response to its customer’s demand.

Difference in electrical level (or potential) between two points, e.g., a conductor and mass. The greater the difference, the higher the voltage. Hydro-Québec supplies its customers' electrical installations at low, medium and high voltage. These voltages are standardized.

Voltage (V) multiplied by current (A) equals power (W).


See also