735-kV Chamouchouane–Bout-de-l'Île Project - Hydro-Québec inaugurates newly constructed facilities at a cost of $1.3 billion

Hydro-Québec’s President and CEO, Éric Martel, and the Québec Minister of Energy and Natural Resources, Jonatan Julien, announced today the commissioning of new transmission facilities built as part of the 735-kV Chamouchouane–Bout-de-l’Île project.

“These new facilities will allow us to meet growing demand in southern Québec while ensuring the reliability of the entire grid. We’re seeing a major construction site come to a close: the largest 735-kV line project built in the north–south axis in 25 years. Over 1,250 people have participated in the construction of some 1,000 towers since 2016,” said Éric Martel. 

"I'm very proud to inaugurate these new facilities. This project is of paramount importance to our government. Reinforcing the power system aligns perfectly with our vision for the electrification of Québec's economy. The project has also resulted in $1.1 billion in economic spinoffs in specialized services and the purchase of goods and materials in the province," said Jonatan Julien.

The project’s three components include:

• A new 735-kV transmission line 420 km long between Chamouchouane substation in La Doré, Saguenay–Lac-Saint-Jean, and the Montréal metropolitan loop.
• The 735/120/25-kV Judith-Jasmin substation, located in Terrebonne and connected to the new line. The substation will meet the needs of both the 735-kV main transmission system and regional and local demand.
• A new 19-km segment of the 735-kV line to supply Bout-de-l’Île substation in Montréal.

Some figures for the Chamouchouane–Bout-de-l’Île project:

• $1.3 billion total cost
• 5,040 km of conductors (cables transporting energy) installed
• 1,000 towers erected
• 33,000 tonnes of steel used
• 2,500,000 construction hours

Thanks to these new facilities, power losses on the Hydro-Québec transmission system will decrease considerably, whereas operating flexibility will increase, and this, to the benefit of all customers.