Hydro-Québec Rate Flex D: automate your peak events
Rate Flex D rewards you for using less electricity during a few winter peaks. Gladys Assistant knows when they're coming and adjusts your home for you.
With Rate Flex D, electricity is cheaper than the base rate about 95% of the time, and much more expensive during a limited number of peak demand events in winter. Hydro-Québec says customers can save up to 20% on their bill, as long as they reduce their consumption during those peaks.
Reducing consumption at 6 a.m. on a cold weekday is exactly the kind of thing people forget. Gladys Assistant, a free and open-source smart home platform, connects to your Hydro-Québec account, knows when a peak or a pre-heat period is in progress, and runs the scenes you choose: pre-heat, lower the thermostats, delay the water heater, and notify you.
How Rate Flex D works
The rules, as published by Hydro-Québec:
- The winter period runs from December 1 to March 31. There are no peak events the rest of the year.
- Outside peak events, energy is billed in two tiers at prices lower than Rate D.
- Peak demand events can happen any day of the week, from 6 to 10 a.m. or from 4 to 8 p.m.
- There are at most 30 events per winter, for a maximum of 120 hours in total.
- During an event, the price rises to more than 45¢ per kWh (46.46¢ with the rates in effect on April 1, 2026), several times the base rate.
- You're notified the day before an event, by email or in the Hydro-Québec or Hilo app.
- During your first winter, if your bill ends up higher than it would have been at the base rate, Hydro-Québec reimburses the difference.
In other words: the whole game is to consume as little as possible during those few hours, without being cold. That's what automation is for.
Rate Flex D vs Rate D
The two residential rates side by side, in winter:
| Rate Flex D | Rate D (base rate) | |
|---|---|---|
| Price outside peak events | Lower than Rate D | Standard two-tier price |
| Price during peak events | More than 45¢/kWh | No peak events |
| When peaks can happen | Dec. 1 to Mar. 31, 6–10 a.m. or 4–8 p.m. | Not applicable |
| How many | Up to 30 events, 120 hours per winter | Not applicable |
| Notice | The day before | Not applicable |
| Risk | First winter protected: refund if Flex D costs more | None, but no savings either |
Flex D pays off when you can shift your consumption out of peak hours. The Winter Credit option, which rewarded reductions without a price increase, is no longer open to new customers since March 31, 2026; contracts already enrolled keep it.
What Gladys does with your Hydro-Québec account
The Hydro-Québec integration creates one device per contract on your account, with:
Whether a critical peak is in progress, and whether you're in the pre-heat window before it, ready to trigger your scenes.
Your daily consumption in kWh and the average daily cost of the current billing period.
The critical hours called so far this winter, and what Flex D saved (or cost) you compared to Rate D.
The average outdoor temperature published by Hydro-Québec, to put your consumption in context.
Whether an outage is in progress at your address, so a scene can warn you.
A primary residence, a rental and a cottage on the same account each get their own device.
Automations that make Flex D pay off
A few scenes that are easy to build in Gladys:
- Pre-heat: when the pre-heat period starts, raise the thermostats by a degree or two so the house stores heat before the peak.
- During the peak: lower the thermostats, then restore them when the event ends.
- Water heater and appliances: cut the water heater with a smart relay and hold the dryer or the EV charger until the peak is over.
- Heads-up: get a notification on your phone the evening before and when the peak starts.
- End of the month: check what Flex D saved you compared to the base rate, directly on your dashboard.
Zigbee thermostats, like the Sinopé models common in Quebec, pair directly with Gladys through Zigbee2MQTT and are controlled locally.
Local, private, and with the devices you choose
Gladys runs on your own machine, a mini-PC or a Raspberry Pi. Your automations run locally, keep working if the internet drops, and work with the thermostats, relays and appliances you choose, from any brand.
The Hydro-Québec integration is a free, open-source community integration, installable in one click. It isn't affiliated with or supported by Hydro-Québec. Its peak-event figures are recent: if you're on Flex D, your feedback on the forum is very welcome.
Go further
Lowering your electricity bill is a whole project:
Track your consumption and act on the data, locally and privately.
Thermostats, relays, plugs and appliances you can control from Gladys.
The Zigbee coordinator to pair your Zigbee thermostats locally.
Why local-first matters and how to build a home that runs without the cloud.
Frequently asked questions
What is Hydro-Québec's Rate Flex D?
Rate Flex D is a dynamic residential rate. In winter (December 1 to March 31), electricity is cheaper than the base Rate D outside peak demand events, and much more expensive during them (more than 45¢/kWh). There are at most 30 events per winter, for a maximum of 120 hours, between 6 and 10 a.m. or 4 and 8 p.m.
How do I know when a Flex D peak event is coming?
Hydro-Québec notifies you the day before, by email or in the Hydro-Québec or Hilo app. With the Gladys Hydro-Québec integration, your home also knows when a peak or the pre-heat period before it is in progress, and can run your scenes automatically.
Is Rate Flex D worth it?
It pays off if you can reduce your consumption during the peak hours, for example by pre-heating before the event and lowering the heating during it. Hydro-Québec says customers can save up to 20%, and during your first winter it reimburses the difference if Flex D ends up costing more than the base rate.
Can I still sign up for the Winter Credit option?
No. The Winter Credit option is no longer available to new customers since March 31, 2026. Contracts that were already enrolled on that date keep it under an acquired right. Rate Flex D remains open to eligible Rate D customers.
Does Gladys work with Hydro-Québec?
Yes, through the free Hydro-Québec community integration. It reports daily consumption, average daily cost, outdoor temperature, account balance and outages for each contract, plus the peak, pre-heat and savings data for Flex D and Winter Credit contracts. It is not affiliated with Hydro-Québec.
Is there a Home Assistant-like tool for Hydro-Québec?
Yes. Gladys Assistant is a free, open-source smart home platform that runs locally on a mini-PC or a Raspberry Pi, like Home Assistant, but designed to be simpler. It connects to your Hydro-Québec account and to your thermostats, relays and appliances to automate Flex D peaks.
Make Rate Flex D work for you
Gladys is free, open-source and runs on your own hardware. Connect your Hydro-Québec account and let your home handle the peaks.