Ontario announces underwater electricity transmission line expansion for Toronto

Ontario is looking to the future and has approved a plan to expand Toronto’s electricity transmission line, according to an announcement made on Wednesday. 

The estimated $1.5-billion project will build a new underwater transmission line — the first of its kind in Ontario — to deliver 900 megawatts of clean energy from the Darlington Nuclear Generating Station to Toronto’s downtown and eastern sectors. 

Energy Minister Stephen Lecce said the city’s current electricity system is expected to reach capacity in the 2030s and that the province needs to act now to meet future demand.

“If we do not act, the consequences are clear: A lack of transmission capacity limits our ability to build new homes, it will delay major infrastructure projects, like our transit expansion, and it will put thousands of jobs and billions of dollars at risk,” he said at a news conference Wednesday. 

He added that the new line would bring in enough power to fuel 900,000 new homes. 

The province is proposing to launch a competitive procurement process to select a transmitter that will keep costs affordable, said Lecce.

The Independent Electricity System Operator (IESO) recommended the creation of an underwater line in order to build a system able to handle extreme weather events, such as flooding or ice storms. 

Loss of power during major weather events has cost Toronto nearly $200 million in lost productivity, said Lecce. 

“We can do better, and that’s why we believe the underwater cable will deliver more capacity than any other option brought forth,” he said, adding the target deadline is set for 2037. 

A third line will strengthen Toronto’s energy system and expand regional capacity to support the build of new infrastructure, such as homes and transit projects, said Jana Mosley, CEO of Toronto Hydro.

“By expanding our region's transmission capacity, we’re investing in a bright, sustainable future for all Torontonians,” she said. 

The IESO engaged with transmitters, Indigenous communities and other local stakeholders through the recommendation process of the underwater line, said IESO CEO Lesley Gallinger in a statement included in the province’s news release. 

In that same release, Mayor Olivia Chow said she applauded the province’s decision to move forward with the project. 

“It’s an exciting example of the province and city working together to build resilient, clean energy infrastructure that keeps costs down, supports good-paying jobs, and powers the projects that will shape Toronto’s future,” she said.