Hydro One seeks OEB approval for two major 500 kV transmission projects

Hydro One 500 kV Transmission Projects advance with OEB applications for new lines boosting capacity, grid reliability and industry growth in Ontario, including the Northeast Power Line and Longwood to Lakeshore, under the leave-to-construct process.

Hydro One Networks Inc. has requested Ontario Energy Board approval to build two major 500 kV transmission lines, filing leave-to-construct applications for the Northeast Power Line and the Longwood to Lakeshore Transmission Line. The company said the projects are intended to boost transfer capacity, strengthen grid reliability and support local industry and agri-business as Ontario demand grows.

The Northeast Power Line is planned as a single-circuit 500 kV line between Hanmer Transformer Station in Greater Sudbury and Mississagi Transformer Station near Wharncliffe. According to the filing, the project is expected to reinforce transfer capability between northeast and northwest Ontario by about 900 MW. Hydro One estimates an investment of approximately $1.8 billion and targets completion in 2029. For additional regional context, readers may consider our coverage of BC AB electricity benefits as broader market developments continue to influence planning decisions.

The Longwood to Lakeshore Transmission Line is proposed as a single-circuit 500 kV line linking Longwood Transformer Station in the Municipality of Strathroy-Caradoc to Lakeshore Transformer Station in the Municipality of Lakeshore. The approximately $1.2 billion investment is anticipated to deliver about 550 MW to the region, supporting jobs in the agri-business and manufacturing sectors, with an expected in-service date in 2030. Related transition themes shaping industrial loads include evolving hydrogen strategies, such as those discussed in Canada Germany hydrogen, which frame long-term electricity needs.

Under Ontario's Section 92 process, a leave-to-construct application is required for transmitters to obtain OEB approval to construct, expand or reinforce the transmission system. Hydro One states that its applications provide details on routing, design, timing and costs. As provincial policy timelines and resource additions drive network requirements, readers may find broader context in Ontario to miss 2030 target, which highlights how planning horizons intersect with infrastructure schedules.

Hydro One also confirmed that proximate First Nations will be offered the opportunity to invest in a 50 percent equity stake in the transmission line component of each project through the company's First Nation Equity Partnership Model. The utility said it will continue collaborating with proximate First Nations on planning, development and construction. Large capital builds elsewhere, including projects like Site C dam, underscore the scale of workforce and supply chain mobilization required for multi-year programs.

Taken together, the filings mark another step in a portfolio of major transmission investments Hydro One says are intended to meet growing electricity demand and build a more self-reliant economy in Ontario. As neighboring jurisdictions refresh their long-term plans, developments such as Hydro Quebec future provide additional perspective on how interprovincial strategies may align with future Ontario system needs.

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