Project description

Meeting the electricity needs of today and tomorrow while supporting economic and social development

To meet the sector’s growing electricity needs, Hydro-Québec will be investing over $500 million to upgrade its transmission system in the north-south axis of the island of Montréal, between the boroughs of Saint-Laurent and LaSalle. As the system’s equipment is aging, it must be replaced.

This project also aims to maintain the reliability of electricity supply and ensure continuity of service over the long term for all the region’s residents.

Hydro-Québec will add approximately 500 MW of capacity to support economic and social development in the following sectors:

  • Commercial and residential development projects
  • Public transit projects such as a Réseau express métropolitain (REM) station and Société de transport de Montréal (STM) garages for recharging electric buses
  • Manufacturing projects
  • Data centers and greenhouses

> $500 M invested

500 MW of planned capacity

18 km of transmission line to convert

3 substations to convert

Electrical system upgrade between Aqueduc and Saraguay substations

The project includes:

  • rebuilding the existing 120-kV Aqueduc–Saraguay overhead transmission line at 315 kV over a distance of 18 km from Saint-Laurent to LaSalle. The line will be rebuilt it in the existing right-of-way, but the route may be optimized at a later stage to mitigate its impacts according to technical, economic, environmental and social criteria.
  • converting three transformer substations — Rockfield substation (in Lachine), Hampstead substation (in Côte Saint-Luc) and Laurent substation (in Saint-Laurent) from 120 kV to 315 kV.

Hydro-Québec will also conduct a preliminary study for the construction of a new substation in the Dorval area as well as the associated supply line.

The line right-of-way for the project is situated in an urban environment that is very dense in places. To harmonize its project with the development approach of each of its municipal partners, Hydro-Québec is working in close collaboration with the towns, boroughs, organizations and residents concerned.

Harmonization with the project to upgrade the transmission system on the island of Montréal

This project is part of a broader plan to upgrade the transmission system on the island of Montréal, where the voltage is being increased from 120 kV to 315 kV.

The conversion of substations and transmission lines to 315 kV began in the eastern part of the island in 2009 (in light green on the map). The conversion project is continuing downtown and in the western part of the island. Projects under study or under construction are shown in dark green.

The next step is to complete an upgrade of the line in the Aqueduc–Saraguay axis and to convert the Laurent, Hampstead and Rockfield substations to 315 kV.

Saraguay substation

Cliquer pour ouvrir la galerie photo du Poste Saraguay

Saraguay substation is the northernmost point of the line that will undergo conversion. It is located in an industrial area and was commissioned in 1959. It supplies power to residences, businesses and industrial operations in Pierrefonds-Roxboro, Dollard-Des-Ormeaux and Saint-Laurent.

Although the substation does not need to be rebuilt, some adjustments must be carried out in order for the line to be converted. A reconfiguration of the towers around the substation and the replacement of equipment inside it are planned.

Diaporama

Following content is a slideshow of: Saraguay substation.

  • Poste de Saraguay 1954. Mise en service : 1959.
    1954: Land use around the substation, which was commissioned in 1959
  • Poste de Saraguay 1975. Mise en service : 1959.
    1975 Land use around the substation
  • Poste de Saraguay 2015. Mise en service : 1959.
    2015 Land use around the substation

Saraguay‑Laurent segment

There are two overhead transmission lines in this line corridor, both operated at 120 kV. One of the lines will be dismantled and rebuilt at 315 kV on the same route.

Diaporama

Following content is a slideshow of: Saraguay‑Laurent segment

  • Copyright Archives d'Hydro-Québec.
    1981 : Hydro-Québec transmission line segment between Saraguay and Laurent.
    Source : Archives d’Hydro-Québec.
  • 2018 : Transmission line segment between Saraguay and Laurent substations.

Laurent substation

Cliquer pour ouvrir la galerie photo du poste Laurent

Laurent substation is located in an industrial and commercial area near the IKEA store in Saint-Laurent. Commissioned in 1962, it reduces the voltage from 120 kV to 12 kV or 25 kV. The electricity then supplies residences, businesses and industrial customers in the Saint-Laurent and Lachine boroughs and the town of Mont-Royal via the distribution system.

As part of the project, new 315-kV, 120-kV and 25-kV equipment will be installed at Laurent substation.

Diaporama

Following content is a slideshow of: Laurent substation

  • Poste Laurentet en 1954. Mis en service en 1962.
    1954 : Land use around the substation, which was commissioned in 1962
  • Poste Laurent en 1973. Mis en service en 1962.
    1973 : Land use around the substation
  • Poste Laurentet en 2015. Mis en service en 1962.
    2015 : Land use around the substation

Laurent‑Hampstead segment

This line corridor contains an overhead transmission line operated at 120 kV. It will be dismantled and rebuilt at 315 kV. The exact route of the line is currently under study. It will be the subject of consultations with the community.

Transmission line segment between the Laurent and Hampstead substations in 2018.

Hampstead substation

Cliquer pour ouvrir la galerie photo du poste de Hampstead

Hampstead substation is located in a residential area. Commissioned in 1955, it reduces the voltage of electricity from 120 kV to 12 kV or 25 kV. The electricity then supplies residences, businesses and industrial customers in Côte Saint-Luc, Hampstead, Montréal-Ouest, Côte-des-Neiges–Notre-Dame-de-Grâce and Lachine via the distribution system.

As part of the project, new 315-kV equipment will be installed at Hampstead substation.

Diaporama

Following content is a slideshow of: Hampstead substation

  • Poste de Hampstead 1954. Mise en service : 1955.
    1954 : Land use around the substation, which was commissioned the following year
  • Poste de Hampstead 1973. Mise en service : 1955.
    1973 : Land use around the substation
  • Poste de Hampstead 2015. Mise en service : 1955.
    2015 : Land use around the substation

Hampstead–Rockfield segment

This line corridor contains an overhead transmission line operated at 120 kV. It will be dismantled and rebuilt at 315 kV. The exact route of the line is currently under study. It will be the subject of consultations with the community.

Transmission line segment between Hampstead and Rockfield substations in 2018.

Rockfield substation

Cliquer pour ouvrir la galerie photo du poste Rockfield

Rockfield substation is located in an industrial area. Commissioned in 1947, it reduces the voltage of electricity from 120 kV to 12 kV or 25 kV. The electricity then supplies residences, businesses and industrial customers in Lachine, LaSalle and Montréal-Ouest via the distribution system.

Rockfield substation will be rebuilt at a voltage of 315 kV.

Diaporama

Following content is a slideshow of: Rockfield substation

  • Occupation du territoire autour du poste qui a été mis en service en 1954
    1954 : Land use around the substation, which was commissioned in 1947
  • Occupation du territoire autour du poste en 1973
    1973 : Land use around the substation
  • Occupation du territoire autour du poste en 2015
    2015 : Land use around the substation

Rockfield–Aqueduc segment

The overhead transmission line between Rockfield and Aqueduc substations travels through the boroughs of Lachine and LaSalle at a voltage of 120 kV. It will be rebuilt at 315 kV.

Transmission line segment between Rockfield and Aqueduc substations in 2018.

Aqueduc substation

Cliquer pour ouvrir la galerie photo du poste Aqueduc

Located in the borough of LaSalle, the Aqueduc substation is the end point of the line that will undergo conversion to 315 kV.

Although the substation does not need to be rebuilt, it requires certain adjustments in order for the line to be converted. A reconfiguration of the towers around the substation and the adjustment of equipment inside it are planned.

Diaporama

Following content is a slideshow of: Aqueduc substation.

  • Occupation du territoire autour du poste qui a été mis en service en 1954
    1954 : Land use around the substation, which was commissioned in 1971
  • Occupation du territoire autour du poste en 1973
    1973 : Land use around the substation
  • Occupation du territoire autour du poste en 2015
    2015 : Land use around the substation