• Skip to content
  • Skip to the footer's menu
  • All sites
  • News
  • Contact us
  • Power outages
  • Français
  • Log in
Hydro-Quebec
  • Residential
  • Business
  • About Us

For an alternative version of the menu below, you can access the sitemap.

  • Display Menu
  • Manage my account
  • Customer Space
    • Manage my account

      Take advantage of our online
      services

      • See your balance, due date and payment history for all your accounts.
      • Report a change of address online.
      • Update your communication preferences.
      • Use our tools to understand your electricity use.

      …and more!

      • Log in
      • Create my Customer Space Click to obtain more informations about your customer space

      What will you need?
      Contract holder: Your most recent bill.
      Proxy holder or account manager: A recent bill of the account you manage.

    • Account and billing
      • Rates and rate options
      • Multiple account search tool
      • Account manager
      • Proxy or consent to disclosure
      • Meters and meter-reading
      • Understanding your bill

        What’s a kilowatthour?

    • Rates
      • Rates and rate options
      • Glossary
      • Helping you understand your electricity rate
      • Understanding power and power demand
      • Service charges
      • Deposit and payment guarantee
      • Comparison of electricity prices
    • Payment
      • Paying your bill
      • Pre authorized debit
      • Online payment
      • Options in case of payment difficulties
      • Enter into a payment arrangement
      • Confirm your payment
    • My electricity use
      • Energy Performance Indicator
      • Factors that influence consumption
      • Breakdown of a household’s electricity use
      • Tools to calculate consumption
      • What you may not know about your electric devices
    • Moving
      • Change address
      • Add address
      • Remove address
      • Become a customer
      • Estimate a home’s electricity costs
      • Successful move
      • Remove or add a contract holder
      • Manage rental
    • Request for work
  • Energy Wise
    • Why be energy wise?
    • Smart thermostats for $0
    • Offers to save this winter
      • Rate Flex D
      • Hilo smart home service
      • Collective contribution – Overall results
    • Financial assistance programs
      • LogisVert Efficient Homes Program
      • Dual energy (electricity and natural gas)
      • Other offers and tax credits
    • Energy efficiency tips
      • Heating and air conditioning
      • Hot water
      • Household appliances
      • Electronics
      • Lighting
      • Pools and spas
      • Building and renovating
  • Safety advice

Rate DT – Dual Energy
for residential and agricultural customers

  • Overview
  • How it works
  • Billing

Rate DT is designed for customers with a dual-energy heating system that uses electricity as the main source of energy and a fuel as the auxiliary source.

Video: Getting the most out of dual energy and Rate DT

Length: 2 minutes 17 seconds

DUAL ENERGY OFFER FOR SUSTAINABLE DECARBONIZATION

You may be interested in a new offer aimed at converting heating systems fueled solely by natural gas to dual energy (electricity and natural gas).

For Énergir customers:

Find out more about the dual-energy offer for sustainable decarbonization

For customers of another natural gas distributor:

Find out more about the dual-energy component of the Chauffez vert program

A dual-energy heating system uses two energy sources: electricity and a fuel, usually natural gas or oil.

This heating system uses electricity as the main source of energy and a fuel like natural gas, oil, propane or wood pellets as the auxiliary source.

Photo of a family in the comfort of their home in winter.
Photo of someone in the comfort of their home in winter.

Rate DT has two different prices for electricity, which apply depending on the outdoor temperature.

Rate DT is more advantageous, except in extremely cold weather, when the temperature is below –12°C or –15°C, depending on the region. But we only have those extreme cold spells a few days a year, so Rate DT is generally cheaper when the appropriate heating source is used at the right time. An indicator light shows what price you’re being billed for your electricity. Also, a dual-energy heating system automatically switches from one energy source to the other.

How it works

The advantages of Rate DT

Generally cheaper than Rate D

On an annual basis, Rate DT is generally cheaper than Rate D for dual-energy customers who use the right energy source at the right time. Keep in mind however that depending on your electricity use habits, Rate DT can be more expensive than Rate D.

The possibility of additional savings in summer

When air-conditioning or a pool heater is used, Rate DT can also help you save on energy costs for systems that run at full capacity in summer.

Everyone benefits

Using your dual-energy heating system lowers the demand for electricity during peak periods, which are generally during winter cold spells. Hydro-Québec can therefore provide Quebecers with a secure supply of electricity at the lowest cost. In this way, dual energy limits the upward pressure on electricity rates, which is quite an advantage for all customers.

Rate DT

/kWh for the energy consumed during most of the year

/kWh for the energy consumed during a cold spell, which only happens a few days a year

Rate D*

/kWh for the energy consumed in the first tier

/kWh for the rest of the energy consumed (second tier)

*Given that most contracts at Rate DT are eligible for Rate D, for simplicity, the only comparison shown here is with Rate D. Contracts that are eligible for domestic rates DP or DM are also eligible for Rate DT if the customer uses a dual-energy system that qualifies for Rate DT.

In effect as of April 1, . In either case, the system access charge will apply.

Who benefits from dual energy?

Dual energy is advantageous for Rate DT customers, Hydro‑Québec and Hydro-Québec customers as a whole! Take a closer look:

Who ? Advantages
Rate DT customers Savings on the vast majority of kilowatthours (kWh) consumed during the year to make up for the high price applied to electricity consumption during cold spells
Hydro‑Québec Better management of demand for electricity during cold spells
Other Hydro-Québec customers Lower electricity rates overall due to lower supply costs during winter peaks

Potential savings with Rate DT (dual energy - electricity and natural gas)

See the potential annual savings with dual energy – electricity and natural gas – at Rate DT on the energy costs of a home with a central forced-air heating system.

If you have central air-conditioning or a pool heater, Rate DT can also help you save on energy costs for these systems that run at full capacity in summer.

Annual consumption*
Average home
with air-conditioning
Natural gas – Heating ()
Electricity – Remaining energy ()
Dual energy
Electricity billed at Rate DT () + in natural gas**
Potential annual savings

* Annual consumption includes space heating, water heating, air-conditioning and other basic uses in an average home (160 m2 or approximately 1,722-sq.ft. detached home, duplex or triplex) in Montréal. The amounts are rounded.

** Space heating with natural gas during cold spells.

Source of prices:

  • Electricity rates effective April 1, .

  • Énergir natural gas rates: average price history from April to March .

Potential savings with Rate DT (dual energy – electricity and oil)

Here is an example of the potential savings for a 158-m2 (about 1,700-sq. ft.) single-family home with four occupants in Montréal with dual energy – electricity and oil – at Rate DT.

Keep in mind, however, that depending on your electricity use habits, Rate DT can be more expensive than Rate D given that electricity consumed during cold spells is billed at a higher rate than it is with Rate D. However, the less electricity you use during cold spells, the more likely you are to save with Rate DT.

Example of potential savings with dual energy – electricity and oil – at Rate DT.
Rate Energy cost Total
Rate D Electricity:
Rate DT Electricity:
Oil: *
Annual savings with dual energy – electricity and oil – with Rate DT:

* Estimated cost of oil: /litre based on the Montréal average for the season. Source: Régie de l’énergie, Relevé hebdomadaire des prix du mazout léger, week of .

Calculating savings at Rate DT

Average energy costs: annual consumption of kWh for space heating, water heating and other basic uses.

Electricity, Rate D:

  • /kWh for kWh consumed (1st tier)
  • /kWh for kWh consumed (2nd tier)

Dual energy, Rate DT:

  • /kWh for kWh consumed when the temperature is above or equal to –12°C or –15°C
  • /kWh for kWh consumed when the temperature goes below –12°C or –15°C

Estimated cost of oil: /l for 255 litres

Electricity bills (at Rate D and Rate DT) include the system access charge of per day.

Maximize savings during the summer

Save even more by lowering your air-conditioning and pool-heating costs!

Air-conditioning or pool heater Central air-conditioning Pool heater
Summer consumption 800 kWh 4,000 kWh
Electricity – Rate D
Dual energy – Rate DT
Annual savings

How to monitor your consumption

You can keep track of your electricity use with the Energy Performance Indicator. Compare your electricity use to the same period from the previous year and discover what lead to increases or decrease in your consumption. This will help you achieve the savings you expected and make the most of Rate DT.

Keep in mind, however, that depending on your electricity use habits, Rate DT can be more expensive than Rate D. Track what leads to increased electricity consumption during cold spells, and make any necessary changes in order to achieve the savings you expected.

Find out about the Energy Performance Indicator

  • Details on the structure of Rate DT
  • Consider these potential solutions if you are not saving as much as expected with Rate DT
  • See the installation specifications for contractors [PDF 445 kB]

Does your heating system make you eligible for Rate DT (dual energy)?

How can I sign up for Rate DT?

Step 1

Begin by asking a heating contractor to check that your dual-energy system complies with the provisions set out in the Electricity Rates [PDF 2.31 MB], in particular with respect to dual energy and Rate DT.

Step 2

Then have the contractor fill out a Certificate of Eligibility – Dual Energy form [PDF 687 kB]. Sign the certificate of eligibility to confirm that you would like to sign up for Rate DT and send it to the address shown on the form.

You will have to pay for the inspection of your dual-energy system, for making the system compliant with the requirements of Rate DT, if necessary, and for the installation of the indicator light, supplied free of charge by Hydro-Québec, which will tell you when the higher price applies. Installation of the indicator light is optional.

Your contractor can obtain a free indicator light by calling 1 800 363-7443.

More information

To find out more about Rate DT, consult Section 5 of Chapter 2 of the Electricity Rates [PDF 2.31 MB].

Other useful information

  • Hydro‑Québec’s Conditions of Service [PDF 2.3 MB]
  • Helping you understand your electricity rate
  • Detailed description of applicable service charges
  • Glossary
  • Tips on how to lower your electricity bill

During most of the year

When the temperature is above or equal to −12°C or −15°C, depending on the region.

During a cold spell

When the temperature goes below −12°C or −15°C, depending on the region.

First tier

Your energy consumption is divided into two tiers. The first tier (1st tier), which is set at 40 kWh per day, or 1,200 kWh per month, is billed at a lower price than the second tier (2nd tier).

Rate

Electricity rate effective April 1, .

Oil

Estimated cost of oil: /litre.

Savings of approximately if annual system maintenance costs are taken into consideration.

Electricity – Rate D

Consumption billed at the first‑tier price of Rate D at April 1, , for consumption associated with central air‑conditioning, and the second‑tier energy price of Rate D for pool heating.

Dual-energy – Rate DT

Consumption billed at lowest Rate DT price, as at April 1, .

Distribution service loop

Any portion of a power line, not located along a public highway, extending the Hydro-Québec system to the connection point.

See the eligibility criteria regarding domestic rates for farms[PDF 693 Kb]

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.

Multiplier

A factor that is applied to the system access charge, to the consumption at the various energy price tiers and to the base billing demand, as applicable depending on the rate.

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).

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).

Winter period

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

Summer period

Period from April 1 through November 30, inclusive.

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).

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).

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.

Minimum billing demand (minimum demand)

The minimum amount of power that customers must pay for each consumption period, regardless of their electricity use. The threshold is set so that customers pay their share of the costs Hydro‑Québec incurs to meet their 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 their projected electricity use.

Electricity as the main source

The dual-energy system in electrical mode uses an electric forced-air system, an electric boiler, a traditional central heat pump or a geothermal heat pump.

Fuel as the auxiliary source

“Fuel as the auxiliary source” refers to a fuel such as natural gas, oil, propane or wood pellets that is used as a second source of energy to heat your home.

Dual-energy system in fuel mode

The dual-energy system in fuel mode must be able to keep your home warm during cold spells without the electrical mode being used at the same time.

Automatic switch

A dual-energy heating system eligible for Rate DT automatically switches from one energy source to the other when it receives a signal from the outdoor-temperature sensor: electricity when the temperature is above or equal to –12°C or –15°C, depending on the region; fuel when the temperature goes below that critical threshold.

Off-grid systems

“Off-grid system” refers to a system that is not connected to Hydro‑Québec’s main grid. In this particular case, it refers to the systems in Îles-de-la-Madeleine, Clova, Obedjiwan or Île-d’Anticosti or one of the Nunavik systems. Rate DT (dual energy) is not available to homes and farms located in those regions.

Electricity as the main source of energy

The dual-energy system in electrical mode uses an electric forced-air system, an electric boiler, a traditional central heat pump or a geothermal heat pump.

Fuel as the auxiliary source

“Fuel as the auxiliary source” refers to a fuel such as natural gas, oil, propane or wood pellets that is used as a second source of energy for your farm’s heating needs.

Dual-energy system in fuel mode

The dual-energy system in fuel mode must be able to keep the farm premises it serves warm without the electrical mode being used at the same time.

Comments:

  1. The installed capacity of each dual-energy system must be no less than 50% of the installed capacity of the premises it serves.
  2. The installed capacity of all premises that are not served by a dual-energy system must not exceed 10 kilowatts.

Off-grid systems

“Off-grid system” refers to a system that is not connected to Hydro‑Québec’s main grid. In this particular case, it refers to the systems in Îles-de-la-Madeleine, Clova, Obedjiwan or Île-d’Anticosti or one of the Nunavik systems. Rate DT (dual energy) is not available to homes and farms located in those regions.

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.

Important links

  • Link to main sections
    • Residential
    • Business
  • Link to some of our sites
    • About
    • Energy Wise
    • Security advice
    • Newsroom
    • Contact us
    • Power outages
    • Careers*
    • Our sites
  • Newsletters
  • Follow us
    • Facebook
    • Bluesky
    • X (Twitter)
    • LinkedIn
    • YouTube
    • Instagram
    • TikTok
  • Apps
    • Apple Store
    • Google Store
  • Site map
  • Terms and confidentiality
  • Manage cookies
  • Accessibility
  • Netiquette
  • Request for access and Privacy

© Hydro-Québec, 1996–2025. All rights reserved. * Website in French only | Who can consult this page