How cold does it have to be to trigger a peak demand event?
There is no pre-established threshold, but the temperature is an important factor.
Peak demand events are scheduled when we anticipate high demand for electricity in Québec in winter. That’s the main consideration. It’s true that on cold days everyone uses a lot of energy at the same time, so the temperature has an impact on demand forecasts. However, demand isn’t always the same for a given temperature. For example, if it is −10°C for several days in a row, demand for electricity will be greater on the last day than on the first.
Other factors that affect the forecasted demand have to do with operating constraints related to electricity supply as well as power transmission and distribution. To manage power demand, Hydro-Québec diligently applies all the means at its disposal, including dynamic pricing.