The Ontario government has declared the Barrie to Sudbury transmission line as a priority project and designated Hydro One to develop and construct it.

The single-circuit 500-kilovolt transmission line that will run approximately 290 kilometres from the Essa Transformer Station near Barrie to the Hanmer Transformer Station in Sudbury. The line will create capacity to deliver up to 1,500 MW of energy to the north and 1,000 MW to the south.

The project is expected to create more than 9,000 jobs.

The province and Hydro One have also committed to leveraging the Canadian and Ontario supply chain, building on Hydro One’s successful track record that saw 93 percent of their $2.9 billion spend in 2024 going to companies based in Canada, supporting thousands of Canadian workers.

“Transmission investments are a crucial part of our plan to meet growing electricity demand across Ontario,” said Sam Oosterhoff, Associate Minister of Energy-Intensive Industries. “These new transmission lines will deliver the power needed to support our people and our industries, and they will drive economic growth across northern Ontario for decades to come. We’re especially pleased to be moving ahead on this project in partnership with the Energy Corridor First Nations (ECFN), whose leadership will be critical to its success and will leave a lasting impact on Ontario’s energy grid.”

Northern Ontario faces a significant transmission bottleneck because its electricity grid was originally designed to serve small, widely dispersed communities and resource-based industries, not the growing demand from mining expansion, electrification, and new industrial projects. With energy demand in the north alone expected to increase 81 percent by 2050, and recent reports predicting 41 potential new mines projected by 2033, the Independent Electricity System Operator’s (IESO) Northern Ontario Bulk Study identified a bottleneck between northern and southern Ontario. The IESO has recommended a two-phase approach:

• Phase 1 is a single-circuit 500-kilovolt transmission line running 290 kilometres from Barrie to Sudbury, that is expected to be in-service in 2032.
• Phase 2 is a second single-circuit 500-kilovolt line that will undergo early development work at this time to ensure the project can materialize quickly when more transmission capacity between northern and southern Ontario is needed.

To support the construction of the line, Energy Minister Stephen Lecce signed a Memorandum of Understanding last December with the ECFN consortium that establishes shared objectives, principles of cooperation, and a framework for joint engagement on this project

The consortium includes 11 First Nations: Henvey Inlet, Dokis, Shawanaga, Wahnapitae, Magnetwan, Moose Deer Point, Nipissing, Atikmeksheng, Alderville, Wasauksing and Mississauga of Scugog Island First Nations. It is expected to grow as additional First Nations join over time.

The transmission project will provide significant partnership and participation opportunities for Indigenous communities, helping to advance economic reconciliation. First Nations will also have access to Hydro One’s First Nations Equity Partnership Model, which will include First Nation leadership in decision-making and 50 per cent ownership of the line. This marks a significant advancement in economic reconciliation with Indigenous peoples of Ontario to drive economic growth and build and upgrade infrastructure in Northern Ontario.