Winter peaks and a mild winter: Hydro‑Québec answers all your questions.

Read time: 4 minutes

With the winter peak season officially over, we can now say: “Mission accomplished!” Did this winter’s mild temperatures have an impact on the challenges and on electricity bills? Read on for the answers to these questions!

Spring is here, so, it’s the perfect time to review our progress and see how change is possible when everyone gets involved! Over the winter months, even more homes and businesses heeded Hydro‑Québec’s call by participating in Hilo challenges or signing up for dynamic pricing, interruptible electricity options or the Demand Response (DR) Option. They did their part to use less electricity when demand was particularly high, like on very cold days between 6 and 9 a.m. and from 4 to 8 p.m. They also managed to use less electricity even during mild weather, resulting in lower electricity bills.

Was winter 2023‑2024 very different from winter 2022‑2023?

Remember February 3, 2023? That day, temperatures in the province hit all-time lows of -48°C in the city of Québec and -52°C at Le Massif mountain in the Charlevoix region, and Hydro‑Québec recorded a historic peak in power demand of about 43,124 MW, exceeding the power system’s capacity of 40,000 MW. It’s at times like these that the public can make a big difference simply by turning the heat up a little prior to a peak demand period and lowering it by a few degrees when the peak period begins. A peak demand period is when everyone uses a lot of electricity at the same time.

One year later, the weather was surprisingly mild. On February 27, 2024, the thermometer climbed to 15°C in Montréal and didn’t once drop below -20°C.

Meteorologists confirm that winter 2023–2024 was one of the warmest in Québec’s history.

The exceptional temperatures certainly had an impact on electricity use. The biggest winter peak took place on January 19, 2024, at 8 a.m. and resulted in a demand of 36,346 MW across the entire power system. A temperature of -15.7°C was recorded in Montréal (Dorval).

Can climate change help us to avoid exceeding grid capacity?

The answer is no. Scientists predict alternating extreme weather events, such as El Niño, which is responsible for this year’s mild weather, and polar vortex disturbances, which lead to cold snaps. Winter peaks are clearly here to stay.

Why did peak demand events take place at -10°C?

Electricity use increases during a cold snap because everyone turns up the heating at the same time. However, it can be high even with moderate temperatures. Hydro‑Québec takes various factors into account when programming peak demand events. For instance, if it is 20°C in a city the size of Rimouski and -10°C in Montréal, the power system can meet the demand (but perhaps not if the opposite is true). However, if it is 10°C for several days, the cumulative effect could lead to higher electricity use. Outages and constraints related to electricity supply as well as power transmission and distribution also contribute to the decision. The goal is to ensure that demand does not exceed the grid’s capacity. This winter, despite the mild temperatures, Hydro‑Québec sent 19 peak demand event notices. That’s the same number of peak demand events as during the 2022‑2023 winter season (which was, in fact, colder) and 10 fewer events than in winter 2021‑2022.

Does it still pay off to use less electricity during peak demand events?

If you participated in Hilo challenges or signed up for the Winter Credit Option, the DR Option or one of the interruptible electricity options, you may have noticed a slight decrease in the cash rewards and credits this year compared with previous years. That is related to the mild weather. This especially applies if you are among the 20% of customers who have already adopted good electricity use habits. The cash rewards and credits are calculated by comparing the kilowatthours used during a peak demand event and your typical electricity use—the smaller the difference, the lower the savings. If you opted for the Flex rate, Mother Nature no doubt helped you maximize your savings.

Thanks to the collective effort of 339,834 homes and 1,330 businesses, electricity demand was reduced by an average of 939 MW per peak demand event—the equivalent of the total output of Sainte-Marguerite-3 generating station. Proof that we can all make a difference!