Eligibility for Rate GD

Rate GD, which applies to medium‑power contracts, is an optional rate offered on backup power sold to independent producers whose main generating source is temporarily unavailable or under maintenance. The electricity purchased is used to replace the energy required for your essential loads and auxiliary services.

Rate GD does not apply if backup generators are the only equipment you use to generate electricity.

Independent producers may also be billed at the appropriate general rate, with the exception of Rate G9.

This information has been simplified. For more details about Rate GD, consult Section 3 of Chapter 4 of the Electricity Rates [PDF 4.83 MB].

Structure of Rate GD

Billing for Rate GD includes the following:

  • An amount for the energy in kilowatthours (kWh) consumed during the period in question. The price that applies depends on the season:
  • An amount for the power in kilowatts (kW) measured during the period in question. The minimum billing demand is equal to the highest real power demand during the 24 consecutive monthly periods ending at the end of the consumption period in question.

Rate GD is a monthly rate, which means the amount billed for power is based on a 30‑day period.

If applicable, the following may lower your bill:

Credit for supply at medium or high voltage

Hydro‑Québec’s rates assume that electricity will be supplied at low voltage. If you have equipment to step down the voltage of the electricity delivered to you or if you use electricity at medium or high voltage, that means reduced costs for Hydro‑Québec. In return, you receive a monthly credit on your demand charge. The credit is determined according to the supply voltage.

Adjustment for transformation losses

Hydro‑Québec bills you only for the electricity you use. This means it absorbs the transformation losses associated with electricity delivery. If metering occurs before transformation, the electricity billed will include energy lost during transformation that does not reach the customer. So that you do not pay for energy losses, Hydro‑Québec grants an adjustment on the billing demand.

See Helping you understand your electricity rate

Rate GD prices in effect

Breakdown of billing

Applicable in certain cases

  • Credit for supply at medium or high voltage
    • Voltage of 5 kV to less than 15 kV $0.6169/kW
    • Voltage of 15 kV to less than 50 kV $0.9888/kW
    • Voltage of 50 kV to less than 80 kV $2.2075/kW
    • Voltage of 80 kV to less than 170 kV $2.7004/kW
    • Voltage of 170 kV or more $3.5683/kW
  • Adjustment for transformation losses 17.902¢/kW
  • If little or no electricity is used, a minimum charge is billed. It is $12.490 per month (30 days) when single-phase electricity is delivered or $37.471 per month when three-phase electricity is delivered.
  • Rates in effect as of April 1, 2021. This table does not replace the Electricity Rates document in any way whatsoever.


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).

Summer period

Period from April 1 through November 30, inclusive.

Winter period

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


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).

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.

  • 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.

Independent producer

A producer of electrical power who either consumes for its own needs or sells all or part of the electricity it produces to a third party or to Hydro-Québec.

Minimum charge (minimum monthly bill)

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