Friday, January 9, 2026
The government of Ontario announced Jan. 7 it has approved a $1.5 billion underwater electricity transmission line from near the Darlington Nuclear Generating Station to Toronto’s downtown core and eastern section.
The up to 900 megawatt transmission line recommended to the Ontario government by the Independent Electricity System Operator (IESO) is the first of its kind, an Ontario government release said.
High-voltage underwater transmission lines have been used in other Canadian jurisdictions such as Newfoundland and Labrador, Nova Scotia, and Prince Edward Island.
“Without a new transmission line, Toronto would have to turn down job-creating investments and reduce housing, which is simply unacceptable. We are thinking ahead and building for the future by approving a new transmission line that will enable 285,000 new homes, power new businesses, and create thousands of jobs. We are also initiating the first IESO-led competitive transmission procurement to reduce costs and maximize benefits for families,” Ontario minister of energy and mines Stephen Lecce said.
“A new underwater transmission line into Toronto will ensure electricity remains reliable for residents and businesses while enabling economic growth. The IESO has engaged with transmitters, Indigenous communities and other interested stakeholders to inform our recommendation for the underwater line which will be procured through a competitive process.” IESO president and CEO Lesley Gallinger added. “This approach will ensure we provide the best value to ratepayers while supplying Toronto’s energy needs for generations to come.”
The Ontario government is proposing the IESO launch a competitive procurement process to select a transmitter informed by a consultation on the procurement design, the release said.
The IESO’s recommendation follows technical analysis of multiple options, prioritizing routes that minimize land-use impacts by leveraging existing corridors, underground infrastructure and pathways, the release added.
development, construction and commissioning of a third transmission line to Toronto is estimated to take between seven to 10 years before completion.
The proposal is detailed in the 2025 Toronto Integrated Regional Resource Plan.
