Sign-up procedure

You must submit your request to Hydro-Québec, indicating your proposed interruptible power, before October 1.

Your interruptible power must be at least 3,000 kW, or 20% of the maximum contract power of the previous 12 consumption periods.

Conditions of application

Conditions Option I Option II
Advance notice – Weekdays 2 hours 2 hours
Advance notice – Weekends 15:30 the preceding day 15:30 the preceding day
Maximum number of interruptions per day 2 1
Minimum interval between 2 interruptions in the same day 4 hours 16 hours
Maximum number of interruptions per winter period 20 10
Duration of an interruption 4-5 hours 4-5 hours
Maximum duration of interruptions per winter period 100 hours 50 hours

Financial compensation

Option I

Fixed credit:

Variable credit:

  • 20.00¢ per kilowatthour of effective hourly interruptible power for each of the first 20 interruption hours;
  • 25.00¢ per kilowatthour of effective hourly interruptible power for each hour between the 21st and the 40th interruption hours inclusive; and
  • 30.00¢ per kilowatthour of effective hourly interruptible power for each of the 60 subsequent interruption hours.

Option II

Fixed credit:

Variable credit:

Examples of total credits (fixed and variable)

Interruption hours Option I
Total credit
Option II
Total credit
10 h 150¢/kWh 85¢/kWh
20 h  85¢/kWh 53¢/kWh
30 h  65¢/kWh 42¢/kWh
40 h  55¢/kWh 36¢/kWh
50 h 50¢/kWh 33¢/kWh
60 h  47¢/kWh 31¢/kWh
70 h  44¢/kWh 29¢/kWh
80 h  43¢/kWh 28¢/kWh
90 h  41¢/kWh 27¢/kWh
100 h  40¢/kWh 27¢/kWh

Overrun penalties

If you don’t honor the terms of your agreement, you will be subject to a penalty.

For more information

If you have any questions about these rate options, contact your commercial officer or designated agent. You can also reach our Business customer services at 1 800 463-9900 or by e-mail at

These explanations have been simplified. For more details about the interruptible electricity option for large-power customers, consult sections 2,4 and 5 of chapter 6 of the Electricity Rates [PDF 1.7 Mb], approved by the Régie de l’énergie.

Winter period

The period from December 1 of one year through March 31 of the following year, inclusive.

Effective interruptible power

An estimate, expressed in kilowatts, of the interruptible power that is on average curtailed by the customer at Hydro-Québec’s request.

Effective hourly interruptible power

For each interruption hour, the difference between:

  1. the product of the maximum power and the contribution coefficient for the consumption period in question; and
  2. the average hourly power.

Contract power

Minimum billing 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.