General rate for medium‑power customers

Rate M applies to your contract if your maximum power demand has reached 50 kilowatts (kW) or more at least once during the last 12 monthly periods.

We are launching a pilot project on dynamic pricing for Rate M customers. If you would like more information about this Flex rate and whether it could apply to your business, please call us at 1 800 463‑99001 800 463‑9900 or write to us at

Switching to another rate

Switch to Rate G9

If your load factor is usually below 30%, Rate G9 may be better for you, because, at this rate, energy carries greater weight than power.

For more information, contact your commercial officer or designated agent. Our Business customer services can also be reached at the numbers in the Contact us section.

Comparison of bills calculated at Rate M and Rate G9

The following table compares four customers with a billing demand of 140 kilowatts (kW), but different load factors.

Case Load factor Energy consumed
Billed at
Rate G9
Billed at
Rate M
Customer 1 10% 10,080 $1,780 $2,821
Customer 2 20% 20,160 $2,905 $3,382
Customer 3 30% 30,240 $4,029 $3,943
Customer 4 40% 40,320 $5,154 $4,504

Billing for a 30‑day consumption period with no discount for supply at medium or high voltage or adjustment for transformation losses (rates in effect April 1, 2023, excluding taxes).

Details on Rate G9

Switching to a large power rate

If your minimum billing demand is 5,000 kW or more, Hydro‑Québec will automatically switch your contract to a large‑power rate: Rate L, if your contract is related to an industrial activity, or Rate LG, in other cases.

If your minimum billing demand is just under 5,000 kW, it may be better for you to switch to Rate L or LG. Discuss your options with your commercial officer or designated agent. Our Business customer services can also be reached at the numbers in the Contact us section.

Planning any changes?

If you plan to buy new equipment, extend your business hours or enlarge or renovate your facility, your use of electricity could increase and it could then be to your advantage to switch to Rate L or LG, or your contract could be switched automatically. Discuss your options with your commercial officer or designated agent. Our Business customer services can also be reached at the numbers in the Contact us section.

More information

This information has been simplified. For more details about Rate M, consult Section 1 of Chapter 4 of the Electricity Rates [PDF 4.75 MB].

Other rate options

If you have a Rate M contract, the following offerings may be of interest to you.

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).

Monthly periods

Period of 30 days, which may begin on any day of the month, established by Hydro-Québec for billing purposes.


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).


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).

  • Low voltage: Voltage of 750 V or less.
  • Medium voltage: Voltage of more than 750 V, but less than 44 kV.
  • High voltage: Voltage of 44 kV or more.


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


Operation that involves increasing or decreasing voltage through a transformer.

Load factor (LF)

Relationship between the energy (in kilowatthours) actually consumed and the amount of energy that can be consumed by using the entire maximum power demand throughout the consumption period. The load factor indicates the utilization rate of maximum power demand for a given consumption period.

Minimum billing demand (minimum demand)

The minimum amount of power that the customer must pay for each consumption period, regardless of electricity use. The threshold is set so that you pay your share of the costs Hydro-Québec incurs to meet your power needs at all times. The minimum billing demand is determined by the conditions of each rate, as indicated in the Electricity Rates.

  • For all rates except Rate L, the minimum billing demand is automatically determined based on the previous winter’s maximum power demand.
  • Rate L customers must set their own minimum billing demand, called “contract power,” based on the amount of electricity they expect to use.

Power demand

Power a customer requires to meet energy needs at a given time. The higher the customer’s energy consumption at a given time, the higher the power demand.

Winter period

Period from December 1 through March 31 of the next year, inclusive.

Minimum charge (minimum monthly bill)

Minimum amount billable for electricity service even if little or no electricity has been used in the billing period.