In very cold weather, it’s best to use as little electricity as possible during peak periods. It’s kind of like driving: it’s best to stay off the roads at rush hour so you don’t make the traffic worse.

What exactly is a peak?

Annual or daily peaks occur when electricity demand is at its highest because so many customers are cranking up the heat or using energy-intensive appliances at the same time. That ties up the Hydro-Québec grid and puts it under the most pressure.

Annual peaks are the time of year when the Hydro-Québec grid is under the greatest pressure. They occur during periods of low temperatures and high winds. Cold snaps lasting several days also increase demand.

Daily peaks are the times of day when the Hydro-Québec grid is under the greatest pressure: weekday mornings, from 6 to 9 a.m., and evenings, from 4 to 8 p.m.

Winter peaks

In Québec, peak periods occur during winter because so many of us heat our homes with electricity.

Main peak:
December to March

Peak hours

Daily peaks occur on weekdays: in the mornings, from 6 to 9 a.m., and in the evenings, from 4 to 8 p.m.

Video : Winter Peaks

When it’s very cold out, electricity use can increase substantially because of the need to heat our homes. Find out why it is important to reduce energy use during winter peak hours and how to make small changes.

Duration : 1 minute 26 seconds

Putting it off is brilliant!

In Québec, electricity use is highest in winter, between December and March. In fact, Quebecers use so much electricity during this period that Hydro-Québec may have trouble generating enough to meet the demand. By making informed choices, you can curb increasing demand, which in turn will help reduce upward pressure on rates.

Then Hydro-Québec will be able to avoid:

  • purchasing power at higher prices from neighboring systems
  • adding equipment to existing generating stations
  • building new facilities to generate electricity

Small changes make a big difference

To relieve pressure on the grid during daily peak periods, we suggest you put off some of your electricity use until later. For once, putting something off is the right thing to do!

Here are a few simple things you can do to make a difference during the winter peak hours, from 6 to 9 a.m. and from 4 to 8 p.m.

  • Turn down the thermostat a degree or two in all rooms, especially those that are unused.

  • Put off running major appliances like dryers and dishwashers.

  • Shorten showers by a minute.

  • Limit hot water use as much as possible.

Did you know?

Starting in winter 2019–2020, Hydro-Québec will propose two new possibilities that will enable you to contribute to the collective effort to use less electricity during critical winter peak periods—and save money to boot!

Frequently asked questions

The electricity produced by Hydro-Québec generating stations meets the needs of Quebecers, except in very cold weather, when demand is at its highest. Hydro-Québec must then purchase power from neighboring networks. The good news is that you can help avoid these costly purchases during peak periods by postponing part of your electricity use to a non-peak period.

In summer, when there is less pressure on our grid, utilities to the south of Québec rely on us to deliver power to meet their peak needs associated with air-conditioning.

Of course not. In the winter period—December to March—there are only about a hundred peak hours during which the Hydro-Québec grid is under extra strain. That’s why we ask you to use less electricity on very cold days, as well as to make a little extra effort on the handful of other days when we make an appeal to the public.

Absolutely, because your heating system uses two sources of energy: electricity and a fuel like oil, propane, natural gas or wood pellets. When it is really cold, which is when the Hydro-Québec power grid is under the greatest pressure, the fuel is used as a source of heat instead of electricity.

Using your dual-energy heating system lowers the demand for electricity during peak periods, which are generally winter cold spells. This gives Hydro-Québec some leeway concerning the amount of electricity it has available to meet Québec customers’ greater demand during these periods and makes it easier to balance high demand with availability.

To do your bit, all you have to do is use your dual-energy system properly by taking a few simple steps when the indicator light is on:

  • Try to reduce your electricity use.
  • Postpone or reduce your use of hot water.
  • Avoid using auxiliary heating systems that run on electricity, such as convection heaters, electric fireplaces and baseboard heaters. If you can’t shut them off, turn them all the way down.
  • Don’t run the washing machine, dryer, dishwasher and other appliances unless you have to.

See for yourself: go to My Consumption Profile to find your hourly, daily, monthly and annual electricity use data. You can also compare your electricity use (daily or monthly) for the past two years and see how it relates to the outdoor temperatures at the time. Since cold weather can affect your electricity use, we recommend checking your Consumption Profile regularly.

For a better understanding of the concepts of capacity and energy, think of a restaurant.

The restaurant has a limited number of seats, let’s say 50. If 200 customers all showed up at once, the restaurant couldn’t feed them all at once, even though it has enough food on hand.

Rather than renting additional tables to meet the high but momentary demand (peak), the restaurant could ask some people to dine earlier, and some, later. That way, the restaurant would be able to serve everyone, just not all at the same time.

In the Hydro-Québec grid, power (or capacity) is equivalent to the number of seats in the restaurant, and energy is the amount of food. Although we always have enough energy in reserve, we may not have enough capacity in peak periods. To meet the temporary demand, we have to buy power, and that’s very expensive.

Video : The Difference between Energy and Power

Power (W) is a generating station's ability to generate electricity at a given time and energy (Wh) is the amount of electricity used by a customer in one hour. Learn more about the difference between power (or capacity) and energy.

Duration : 0 minutes 47 seconds