Why provinces are ramping up transmission-line infrastructure

Canada’s aging transmission-line infrastructure will need an overhaul to meet the country’s targets of net-zero emissions by 2050.
Provincial utility providers have ramped up transmission-line projects to support increasing electricity demands and transition to renewable energy over the past couple of years, says Ali Hooshyar, Canada Research Chair in electric power systems and an associate professor of energy systems at the University of Toronto.
BC Hydro, for example, announced plans to invest $36-billion over the next decade in non-generation power infrastructure – including $3.5-billion on high-voltage transmission lines between Prince George and Terrace. Ontario’s Hydro One has four major transmission projects planned, SaskPower announced in October a proposal to build new transmission lines to North Dakota, and Alberta is building a new 130-kilometre transmission line to strengthen its grid and ready the province for new renewable-energy generation.
But the pace of investment is far slower than it needs to be, Mr. Hooshyar says. “I would be really surprised if we could actually meet those future maps that system operators and utilities contemplate.”
Part of the challenge of adapting the current system stems from the difference in how renewable energy is controlled and distributed through transmission lines. With conventional power plants such as hydro, nuclear or coal, power is generated by a rotating turbine.
“In solar plants, nothing is rotating, everything is static,” Mr. Hooshyar says. Renewable energy tends to be intermittent or less consistent when it comes to output, which means it needs to be throttled to ensure the system does not get overloaded. A discrepancy between the voltage generated at a plant and the grid’s frequency would require the whole grid to shut down.
“[The industry] is developing new standards for determining the behaviour of renewable energy sources so that there is some level of predictability and transmission lines are less impacted,” Mr. Hooshyar says. But there are other challenges.
“The utility grid has evolved over the last century to be one way,” says Tim King, vice-president of the North American business unit for Nexans, a global player in cable manufacturing for transmission lines. The company has three manufacturing plants in Canada.
Energy gets generated and then moves toward its end customers. “With renewables – whether it’s solar or wind – it’s really important you can store that energy in the system because it’s intermediate power,” he says. “So you generate it when you’re able to, then you have to be able to store it – that creates a totally new grid called a ‘bi-directional grid.’”
Power needs to travel both ways. “Our current grid was never built for that,” he adds.
Mr. King says another factor influencing transmission-line design is a concept called ‘grid hardening’ – strategies utility providers use to protect their lines from extreme weather. He points to California, where lines are being buried to make them more resilient during wildfires.
“Ontario is putting submarine cables underground through lakes,” he says. Part of that is about reducing the environmental impact by limiting the number of transmission lines and poles. It’s also less expensive compared with conventional transmission line infrastructure, he adds.
But from a pan-Canadian vantage point, Mr. King says the electrical grid’s province-by-province design hinders its resiliency. “There are challenges as it relates to interconnection between the provinces, which will be critically important in the future,” he says, using a hypothetical ice storm in Quebec as an example. “If their grid goes down, Ontario could send its nuclear power into Quebec … [but] we’re still not there yet.”
An appetite for partnership and innovation will be key for meeting Canada’s net-zero goals, says Normand Mousseau, academic director of the Trottier Energy Institute at Polytechnique Montreal and a founding director of The Transition Accelerator, an organization focused on innovative zero-emission solutions.
“There’s no point in each province trying to reinvent the wheel by itself,” he says. “Utilities have to talk to each other, share the cost of this development, and test new technologies quickly and at scale.”
Mr. Mousseau points out that 2050 is an ambitious goal, and adds that when upgrading transmission lines, the focus should be on climate change. As we look to electrify as a low-carbon energy solution – especially as it relates to heating – energy demand will rise across the country in the winter. “In the summer, you have to cool by 10 degrees but in the winter we have to heat up by 30 to 40 degrees,” Mr. Mousseau says. “That increases the challenge even more because we will have to produce electricity and deliver it at the same time.”
Transmission wires will play a massive part in that.
“We need to increase the amount of energy we carry,” Mr. Mousseau says. “[And] upgrade the lines in the cheapest and fastest way possible.”