Nova Scotia’s offshore wind transmission line could cost $10 billion: premier

A Block Island Wind Farm turbine operates, Dec. 7, 2023, off the coast of Block Island, Rhode Island. THE CANADIAN PRESS/AP-Julia Nikhinson

HALIFAX — It could cost between $5 billion and $10 billion to build a transmission line that would connect Nova Scotia’s proposed offshore wind farms with the rest of the country, Premier Tim Houston says.

The rough estimate follows his announcement last week that Nova Scotia wants to license enough offshore turbines over the next 10 years to produce 40 gigawatts of electricity — eight times more than what was originally planned.

“It’s a concept,” Houston said after a cabinet meeting Thursday, referring to the Wind West project. “It’s a very powerful concept .... My objective, initially, was to capture the imagination of Nova Scotians.”

For context on the size of Houston’s ambitions, Nova Scotia, with just over one million people, requires 2.4 GW at peak demand. The Brussels-based Global Wind Energy Council issued a 2025 report saying China’s offshore wind turbines were producing just under 42 GW as of last year. The council says the global offshore wind energy industry added 11 GW in 2023 and 8 GW in 2024.

Houston went on to say the project would require “hundreds” of wind turbines to be built in water about 100 metres deep, about 25 kilometres offshore.

A renewable energy expert, however, said it will take far more turbines to generate 40 GW of reliable electricity, assuming that a peak capacity of 66 GW would be required. Sven Scholtysik, a research director at Net Zero Atlantic, said that based on the current industry standard of using 15 megawatt turbines, Wind West would require construction of more than 4,000 offshore turbines.

Despite that big number, Scholtysik said there would be ample room for them amid the 19,500 square kilometres within the five “wind energy areas” selected in January by an independent committee appointed by the federal and Nova Scotia governments.

When asked how long it would take to build such an ambitious project, Scholtysik said it would be difficult to come up with an accurate timeline.

“When we look at how long it takes to build an offshore wind park, that 10-year number is about right,” said Scholtysik, who’s research focuses on electricity, clean fuels and modelling. ”But that ambition to install 66 GW is likely going to require multiple projects, not one single project.”

Tina Northrup, a lawyer with the East Coast Environmental Law Association, said Houston’s 10-year time frame does not seem feasible, given the need for consultations and environmental studies.

“It would be unrealistic to have that much offshore wind infrastructure out into the water in a short period of time,” she said. “We understand this to be a vision that might be realized decades into the future. It wouldn’t be an all-at-once kind of thing.”

As for Houston, he has said he floated the idea on June 2 to get the attention of Prime Minister Mark Carney, who has asked provincial and territorial leaders to submit bids for infrastructure projects to help Canada withstand the trade turmoil caused by U.S. President Donald Trump.

“I think Nova Scotians are pretty inspired by what’s possible,” Houston said. “This would change Nova Scotia and Atlantic Canada and provide green, renewable energy that the world is looking for.”

The Progressive Conservative premier has said he wants Ottawa to help cover the costs of Wind West, saying the excess electricity could supply 27 per cent of Canada’s total demand.

If his plan is successful, Nova Scotia would become an “energy superpower” that no longer requires federal equalization payments, he said.

“We could get off of that transfer system over the next 20 years if we pursued the opportunities that are available to us.”

Houston went on to say Nova Scotia’s offshore is blessed with strong, remarkably steady winds.

Scholtysik, whose research group gets most of its funding from provincial and federal governments, confirmed that the wind energy industry is well aware that Nova Scotia’s offshore winds are among the strongest and most consistent in the world.

A study from the wind energy research firm Aegir Insights, based in Denmark, found that Nova Scotia’s offshore has a “world-class wind resource,” with almost all areas recording consistent wind speeds between 9 and 11 metres per second.

“The consistent availability of good wind resources across the entire offshore territory means that wind speed will likely not be a restricting factor when it comes to siting offshore wind farms,” the 2020 study says.

This report by The Canadian Press was first published June 13, 2025

By Michael MacDonald