Hydro-Québec filed the 2017 progress report on its Electricity Supply Plan 2017–2026 with the Régie de l’énergie. The report updated the energy and power demand forecast calculated before the addition of new markets and new customers such as data centers.

Energy requirements are expected to increase by 2026, though not enough to fully deplete the energy surplus. The Demand Response Program will mitigate the effect of the anticipated increase without reducing the capacity deficiency.

Hydro-Québec is moving ahead with its plan to convert off-grid systems to cleaner energy sources to reduce supply costs and its environmental footprint.

Under our demand response strategy, we have planned various initiatives to reduce or shift peak electricity consumption. Programs available to our residential customers target three-element water heaters and dual-energy systems. For business customers, we rely on our new Demand Response Program.

Video: Peak demand

Electricity demand is cyclical and peaks when there is a sudden increase in the energy consumed by all our customers. Demand is higher in the mornings and late afternoons when people return home from work and prepare dinner. Since most homes in Québec use electric heating, we face our biggest challenge in the coldest weather: winter peak, the time of year when demand is at its highest. (in French only)

Capacity and energy

Electric power or capacity is measured in watts (W) and corresponds to the ability to instantly respond to a request. A restaurant’s capacity, for example, is determined by its number of tables.

Energy, on the other hand, corresponds to the work performed or capable of being performed in a given timeframe. It is measured in watthours (Wh). In the restaurant example, the energy would be the number of meals that can be served in an hour, a week or a year.

During peak periods, even if there is enough food, the restaurant might run out of tables, and people would have to wait in line. For the power grid, waiting is not an option: it must be able to meet capacity demands at all times. If the consumption peak is too high, either demand must be reduced (which is possible thanks to interruptible electricity options) or additional capacity must be purchased from neighboring grids.

In cases like Hydro-Québec’s, where electricity is generated almost entirely from water, the energy reserve is based on reservoirs whose storage can be managed on a multiyear basis.


  • Power gains of 900 MW during winter 2017–2018 were achieved by large and medium-power customers who chose interruptible electricity options. Gains of 1,000 MW are targeted for upcoming winters.
  • The technical feasibility of remote control for dual-energy heating systems was validated as part of the interruptible dual-energy pilot project for residential customers.
  • The demonstration project on residential load curtailment for baseboard heaters continued. Measures like occupancy sensors will be tested to assess energy gains.

See also