Commissioning of the Appalaches–Maine interconnection line

Montréal – Today, Hydro-Québec started delivering electricity through the Appalaches–Maine interconnection line under the terms of the 2018 contract with Massachusetts electricity distribution companies. This interconnection is the first major expansion of HVDC infrastructure linking Hydro-Québec’s grid to neighbouring markets since the inauguration of the Radisson–Sandy Pond line in the early 1990s.

Several Hydro-Québec teams dedicated their efforts and expertise to designing and building this strategic 100-km infrastructure across Québec. On the US side, our partner constructed a 230-km transmission line in Maine.

Among the project’s highlights are the creation of a new family of towers that blend more seamlessly into the landscape, a crossing of over one kilometre at the former Asbestos mine in Thetford-Mines and the integration of four of the largest transformers in Hydro-Québec’s power system.

The Appalaches–Maine line adds a strategic link to Québec’s energy security. Thanks to the interconnection’s two-way transit capability, Hydro-Québec will eventually be able to use it to both export and import electricity.

The energy delivered to New England will support the region’s decarbonization efforts by reducing its reliance on thermal generating stations to meet its essential power needs. Hydro-Québec’s renewable hydropower is expected to lower greenhouse gases by 3 million tonnes annually—the equivalent of taking 700,000 vehicles off the road each year.

Regional benefits

The transmission line crosses 11 municipalities in the MRCs of Appalaches and du Granit. These communities will benefit from the positive impacts of the Integrated Enhancement Program, through which Hydro-Québec funds local initiatives that improve quality of life, with input from local residents. The Appalaches–Maine project will provide $5.5 million to support projects, including the improvements to the Sainte-Praxède community centre and development of parks and trails in Saint-Joseph-de-Coleraine and Thetford-Mines.