News and Press Releases

For immediate release March 1, 2023


Gatineau, March 1, 2023 – Today, Hydro-Québec presented its preliminary analysis of the causes of the outage that occurred on February 4 and 5, 2023, to the mayors of L’Isle-aux- Allumettes, Chichester, Sheenborro, Mansfield-et-Pontefract and Waltham, to the Prefect of the Pontiac MRC and to the Member of the National Assembly for Pontiac. During the meeting, the actions taken and to be taken in the future to prevent a similar situation were also discussed.

Configuration of the power system in the Upper Pontiac

For several reasons, the power system that serves Upper Pontiac is synchronized with the Ontario system. If needed, it can also be synchronized with and supplied by the Québec system. In either case, Hydro-Québec uses the energy it purchases from Waltham and Chutes- Coulonge generating stations, which belong to Evolugen, to supply much of the electricity distributed to its customers.

Extreme cold and record power consumption

On Saturday, February 4, when the system supplying the Upper Pontiac was synchronized with the Ontario system, events that occurred on the Ontario system triggered a major outage. Despite several attempts and access to Waltham generating station’s production, Hydro- Québec was unable to restore power. At that time, Québec’s electricity consumption was reaching a historic peak due to the extremely cold weather. Hydro-Québec tried to supply the sector with the Chutes-Coulonge generating station, as well available to supply, and the Cadieux substation located further east, but this attempt was also unsuccessful. Therefore, customers in the sector were asked to limit their heating to one room per building to help facilitate service restoration. On Sunday evening, February 5, thanks to operations performed by Hydro-Québec teams and the cooperation of local residents, power was restored to the entire sector. The generators that had just been dispatched to the site did not even need to be used.

Increased redundancy and robustness

To ensure grid redundancy and robustness, Hydro-Québec has developed a three-pronged approach in response to this situation. First, a procedure was developed to supply this sector using the Québec system should issues arise on the Ontario system. Second, Hydro-Québec established connecting links that allow power to be added via generators dispatched to the site. Finally, the trip thresholds of the breakers installed on the power line from Cadieux substation were raised, meaning more electricity can be transported on that power line. These three approaches will contribute to the redundancy and robustness of the power system in the Upper Pontiac.

On-site patrols

Hydro-Québec crews are currently patrolling the entire sector affected by the outages of February 4 to determine what additional work would be needed to help ensure power is restored more quickly in the future. Other solutions are also being studied. Evolugen continues to cooperate fully with Hydro-Québec in this matter.

“Over the past few years, considerable efforts have been invested to improve the quality of the service in the Upper Pontiac, including extensive vegetation control and technical upgrades. We understand the community’s concerns following the recent major outage. We remain steadf ast in our commitment to continue our efforts to improve service reliability with the same energy and determination,” noted Alain Paquette, Advisor – Community Relations at Hydro-Québec.

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Hydro-Québec Community Relations
Lanaudière, Laurentides, Laval and Outaouais

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