Hydro‑Québec's Electricity Rate Terms

Consumption period

Period during which electricity is delivered to the customer and which extends between the two dates used by Hydro‑Québec for calculation of the bill.

Maximum power demand

Maximum power measured during a consumption period. It is the higher of the following two values: real power in kilowatts (kW), or a percentage (90% for domestic rates and small- and medium-power rates, or 95% for large-power rates) of the apparent power in kilovoltamperes (kVA).

Contract power

Minimum demand that a large-power industrial rate customer (Rate L) agrees to pay and that Hydro‑Québec must be ready to supply at any time in response to the customer’s demand.

Real power

Amount of electricity consumed in a useful manner to operate equipment, such as a motor or a heating or lighting system. Real power is expressed in kilowatts (kW).

Power

Total amount of electricity supplied at a given time. Expressed in kilowatts (kW), power is the combined effect of voltage, expressed in kilovolts (kV), and current, expressed in amperes (A).

Voltage

Difference in electrical level between two points, expressed in volts (V).

Energy

Power used by electrical equipment over a given period of time. Expressed in kilowatthours (kWh), energy is calculated as power, expressed in kilowatts (kW), multiplied by the time during which the power is used, expressed in hours (h).

The formula for energy is as follows: energy (in kilowatthours) is equal to power (in kilowatts) multiplied by duration of use (in hours).

Energy (kWh) = power (kW) x time used (h).

Apparent power

Amount of electricity that Hydro-Québec supplies to a customer, expressed in kilovoltamperes (kVA). When it is used, apparent power breaks down into real power (kW), which runs devices, and reactive power (kVAR), which produces magnetic fields and which is not useful power for the customer.

System access charge

A set amount, expressed in dollars per month or cents per day depending on the applicable rate, that the customer must pay for the electricity service.

Beginning April 1, 2019, the term fixed charge was replaced with system access charge.