A dual-energy home uses electricity for about 70% of its heating and natural gas as backup during cold snaps. Hydro-Québec\'s Rate DT bills electricity around 5.13 ¢/kWh when the outdoor temperature is warmer than -12 °C / -15 °C, and around 30.00 ¢/kWh when it is colder. The gas runs almost entirely during the expensive cold periods, so the colder the snap, the more the backup fuel saves you.
Above -12 °C / -15 °C, electricity is around 5.13 ¢/kWh, cheaper than Rate D. This is most of winter and all the shoulder seasons.
Below the threshold, electricity jumps to around 30.00 ¢/kWh, so the system automatically switches to the gas backup. The expensive electricity hour rarely happens.
The non-obvious fact: Rate DT is the only Hydro-Québec rate that rewards cold weather. Every degree below the threshold is an hour the gas backup runs and the expensive electricity hour does not.
The patterns that lead Quebec homeowners to misjudge dual energy:
The belief that makes dual energy look like a niche
"Dual energy is for people who already have a gas furnace." Half true. The eligibility rule is that you must be a connected gas-heating customer for 12+ months before the application, but the structural reason the program exists is not about people who have gas. It is about people who have both wires and a fuel source, who can therefore offset peak electricity demand on the coldest days of the Quebec winter, the days that drive Hydro-Québec\'s grid sizing.
That is why Hydro-Québec is targeting 100,000 residential dual-energy customers and a 70% reduction in their heating-related gas use. The point is not to grow gas demand. It is to compress the peak winter electricity demand into a smaller envelope by letting gas absorb the spike.
Why most dual-energy explainers miss the point
Generic explainers describe dual energy as "a way to save on heating". That framing ignores the system-level reason Hydro-Québec, Énergir and Énbridge Gaz Québec built a joint program around it. The single most expensive hour for the Quebec electricity grid is the cold-snap morning peak: a January day at −20 °C between 6 and 9 a.m. when half a million electrically-heated homes try to bring the indoor temperature back up. Building generation and transmission to cover that one hour costs more than building it for any other hour of the year.
Rate DT plus the Chauffez vert grant is the cheapest way for Hydro-Québec to make that one hour disappear from 100,000 homes. The household saves because the rate spread rewards burning gas exactly when the wires are most stressed. The grid wins because the demand is gone. The program subsidises the alignment.
How Rate DT compares to Rate D on the actual bill
Rate DT is not a discount on Rate D. It is a different price structure that wins in one direction and loses in the other.
| Scenario | Rate D pays | Rate DT pays | Net effect |
|---|---|---|---|
| Mild day, 0 °C, electric heat | 10.80 ¢/kWh | 5.13 ¢/kWh | DT cheaper |
| Cold snap, −18 °C, gas backup running | 10.80 ¢/kWh on the electricity portion | Gas commodity price on most of the heat | DT cheaper (gas usually undercuts cold-period electricity) |
| Cold snap, system fails to switch | 10.80 ¢/kWh | 30.00 ¢/kWh on all electricity | DT much more expensive, fix the equipment |
| Shoulder season, 10 °C | 6.89–10.80 ¢/kWh | 5.13 ¢/kWh | DT cheaper for the whole season |
Rate D and Rate DT ¢/kWh prices effective 2026-04-01, before taxes. Source: Hydro-Québec 2026 Electricity Rates chart (PDF).
In the southern, more populated parts of Quebec the switch happens at −12 °C. Further north (e.g. Saguenay–Lac-Saint-Jean), the threshold is −15 °C. Hydro-Québec set the regions based on typical heating-degree-day curves so the program economics work out roughly the same across the territory.
The grant assumes the system swaps to gas automatically when the threshold is crossed. A manual switchover or a system that drifts off-spec disqualifies the installation from the -year stay-on-rate clause. Get the commissioning report and keep it.
When gas prices spike (cold winter, supply disruption, market events), the dual-energy household pays the spike directly because that is when the backup runs. Hedge against this by following Énergir or Énbridge's commodity outlook each fall.
Leaving Rate DT before the 10-year mark, for any reason that is not selling the house to a new dual-energy customer, can trigger partial recovery of the Chauffez vert grant. Verify exit conditions in your enrolment paperwork.
A detached, semi-detached, row house or condo unit with its own heating gets $7,300 when the gas distributor is Énergir and $6,800 when it is Énbridge Gaz Québec. The amount is set this way because the two distributors have different network costs the program is balancing against. Eligibility requires you to add an electric central heat pump to an existing gas system; whether you also replace the gas boiler is your call.
Tool: Rate D vs Rate DT annual saving estimator
Estimate your annual saving by setting how many "cold" hours your region sees and how much of your heating runs on electricity. The widget compares the two rates assuming the gas backup actually switches.
A typical 3-bedroom in Montreal: 8,000–14,000.
Montreal climate: ~0.15. Saguenay: ~0.25.
Default 9 ¢. Check Énergir / Énbridge invoice for actual.
All heating billed at second-block rate.
Electricity + gas combined.
Estimate ignores the system access charge and equipment fuel-conversion efficiency, both of which favour Rate DT for properly-sized installations. The $7,300 / $6,800 Chauffez vert grant is not included here; it is paid one time, this widget shows year-on-year operating cost only.
Source: Hydro-Québec Rate DT, Énergir dual-energy program, Chauffez vert program description on quebec.ca.
The non-obvious thing: dual energy is a grid-capacity trade
Households read dual energy as a personal-finance optimisation: pay less for heat. Hydro-Québec reads it as a way to avoid building expensive generation and transmission for one bad week of January. The Chauffez vert grant ($7,300 / $6,800) is large because the alternative (a new transmission line, a new pumped-storage facility, or an out-of-province purchase) is much larger per displaced kilowatt.
That framing has two practical implications. First, the grant is more durable than a typical retail rebate; it is funded out of grid-investment savings the utility models on a multi-decade horizon, not out of an annual marketing budget. Second, when Hydro-Québec\'s 2035 Action Plan ramps up the energy transition, dual energy is one of the rare programs that can scale immediately because the equipment and rate already exist. A future expansion (more eligible buildings, larger grant, faster onboarding) is more likely than a contraction.
What to actually do, in order
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01Confirm you are a connected gas-heating customer.
You need to have been a connected Énergir or Énbridge Gaz Québec customer for 12+ months before applying. If you are not yet on gas, that is a prior project, not part of Chauffez vert.
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02Run the estimator above honestly.
Use your real annual heating kWh, the cold-hour share for your region, and a current gas commodity price. If the verdict is "skip dual energy", a cold-climate heat pump on Rate D may be a better fit, read the LogisVert guide.
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03Get quotes from an RBQ-licensed contractor.
The Chauffez vert grant requires the work to be done by a contractor holding the right Régie du bâtiment du Québec (RBQ) licence. Ask for the licence number on every quote and on the final invoice.
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04Apply through quebec.ca before installation.
Chauffez vert is application-based. Submit through the Quebec.ca portal before purchase. Pre-approval is the safest sequence; some homeowners have had post-installation applications rejected on documentation grounds.
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05Switch to Rate DT through Customer Space after commissioning.
Once the dual-energy hardware is installed and commissioned, request the Rate DT switch through Hydro-Québec's Customer Space. The change takes effect at the start of the next billing cycle.
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06Keep the commissioning report for 10 years.
The -year minimum-stay clause and any future grant audits will reference the commissioning report. Filing it digitally is enough; do not throw away the paperwork.
Why this matters in 2026 specifically
The 2026 backdrop is decisive for two reasons. First, Hydro-Québec\'s residential rate increased by 3% on April 1, 2026 and the gap between Rate D and Rate DT widened in absolute terms. Second, the 2035 Action Plan formally adopted dual energy as one of the four levers Quebec is using to defer about $100 billion of generation and transmission investment. The grant economics are healthier than they have been since the program launched.
The practical window for a household considering dual energy is the late-spring through early-fall period of any year: the application takes weeks, contractors are booked solid in October, and a January installation that is not commissioned before the first cold snap loses one winter\'s worth of saving. The cost of waiting another year is the same year of saving, plus whatever the rate moves to on April 1, 2027.
