Increasing capacity of the power system at the 315/25‑kV Saint‑Jean substation
- Region
- Montreal
- Status
- In progress
- Type
- Transport
- Expected end date
- 2030
Upgrading and increasing capacity of the power system at the 315/25kV Saint‑Jean substation and connection to the distribution system
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Project overview
Meeting the growing electricity needs of customers in Montréal’s West Island
To meet growing electricity demand in Montréal's West Island and contribute to improving service quality, Hydro‑Québec plans to continue work on upgrading the power system through 2030 as part of its infrastructure modernization program.
The substation’s capacity increase is part of Hydro‑Québec’s strategy to upgrade its electricity transmission infrastructure, and supports Priority 1 of the company’s Action Plan 2035, which focuses on improving service quality.
The work will involve dismantling older equipment to free up space inside the substation and installing new, higher-capacity electrical equipment.
Saint‑Jean substation, in operation since 1957, initially operated at 120/12 kV but had most of its equipment converted to 315/25 kV in 2021. Saint‑Jean substation is located in Dollard‑des‑Ormeaux, at Saint‑Jean and De Salaberry. It supplies electricity to parts of Dollard‑des‑Ormeaux, Pointe‑Claire, Kirkland and Beaconsfield, serving approximately 5,900 customers.
Map of work at Saint-Jean substation
The work involves multiple stage at the substation location and includes connecting part of the West Island to the underground distribution system.
- Dismantling of the 120/12–kV equipment
- Addition of a 315-kV busbar
- Addition of four 25-kV capacitor banks
- Expansion of the 25-kV operation building
- Addition of a third 315/25-kV transformer
Occupation of two parcels of land during the construction period
Most of the work to upgrade the system and increase capacity at Saint-Jean substation will take place on land owned by Hydro-Québec. However, two adjacent lots owned by the city of Dollard-des-Ormeaux will also be put to use during the project, primarily for materials storage, site access and parking for construction workers.
These additional lots are required due to limited available storage space within the substation as well as to route construction access away from Boulevard Saint-Jean, both for safety reasons and to minimize impacts on traffic. The work is expected to span approximately four years.
Work impact and mitigation measures
Throughout the project, Hydro‑Québec will work closely with the community, including the cities of Dollard‑des‑Ormeaux and Pointe‑Claire, to identify the appropriate measures for minimizing the work’s impact. Communications will also be issued about each major milestone.
Send us your comments
More than ever, our teams are committed to working with the community to deliver this major project that will benefit residents of Montréal’s West Island. We’ll keep the conversation with residents open throughout the entire project.
Work calendar
-
2026‑2027
2026 to 2027: Dismantling the substation’s 120/12-kV equipment and installing 315/25-kV equipment
-
2028‑2030
Adding a third 315‑kV transformer and expanding the control building
Underground connection of multiple lines to supply Montréal’s West Island
-
2030
Commissioning the control building
The vital role of substations
What’s an electrical substation and how does it work?
Explore an electrical substation. Discover the vital role it plays in the transmission and distribution of electricity, from the generating station to the home.
Running time: 5 minutes [in French only]
Let’s stay in touch
We want to keep the lines of communication open. Please send us your questions and comments about the project.
- Info‑Project Line : 1 866 388‑1978
- affairesregionales@hydroquebec.com