Thermal Uprating of 161 kV and 230 kV transmission lines

Two lines needed to be upgraded to allow enhanced operating temperatures in order to integrate the 2,000 MW of energy produced by wind farms in different regions of the Bas Saint-Laurent and Gaspésie regions to the Hydro-Québec power grid.

A 120 km 161 kV line connecting Goémon and Copper Mountain substations was enhanced from 49˚C to 95˚C, and 99 km of 230 kV double-circuit lines connecting Rivière-du-Loup and Rimouski substations was enhanced from 49˚C to 75˚C. Interventions were required at 109 sites to ensure sufficient ground clearance based on the new operating temperatures.

In addition, all provincial road crossings had to be secured based on current standards, involving doubling insulators, carrying out analyses based on current climatic criteria (increased ice loads), and adding full dead-end structures where needed.