The audacious plan to build a giant green powerline under the Atlantic

Vast volumes of green electricity could be flowing through a 4,000-kilometre underwater powerline between Canada and Europe by 2040, if three UK-based investment bankers’ vision for a major new transatlantic energy artery becomes reality.

Their $30 billion-plus project, the North Atlantic Transmission One Link (NATO-L), was sparked in 2022, when the sabotage of the giant Nordstream gas pipeline crossing under the Baltic Sea exposed the EU’s dangerous overdependence on Russian energy resources. 

But now, with US tariffs motivating Canada to pivot toward "strengthening ties with reliable allies" in Europe for trade and security, as Prime Minister Mark Carney recently stated, an opportunity is emerging on both sides of the Atlantic.  Laurent Segalen, one of the founders along with Gerard Reid and Simon Ludlam, of NATO-L, calls it a “crystallizing moment” for the project.

“Nothing is more powerful than an idea whose time has come,” Segalen told Canada’s National Observer, quoting French novelist Victor Hugo. 

“The trigger was the attack on Nordstream, but this is about the longer-standing issue of strategic flexibility of energy import and export – and the mutual benefits that come with that,” he said.

“Yes, there are challenges [in building NATO-L], but nothing that can’t be overcome. Ultimately, the bigger the grid, the better it is for everybody, in terms of the cost of electricity, energy security, economic development and so on.”

Industrial infrastructure

Industrial infrastructure has been laid across the Atlantic since 1866, when the first permanent telegraph cable was reeled out from Britain to the US. A pioneering telephone trunkline, known as TAT-1, was installed on the seabed 90 years later. 

And though high-voltage direct current (HVDC) power lines like NATO-L are more technologically complex and costly than telecommunications cables, the planned 6-gigawatt (GW) transmission line is one of a growing number of long-distance HVDC mega-projects in development around the world today. 

Two of the more advanced are the 4,000 kilometre XLinks line planned between Morocco and the UK and the 5,100-kilometre AAPowerLink that would connect Australia to Singapore, though both these are export lines rather than two-way interconnectors like NATO-L.

Segalen points to the 765-kilometre Viking Link that since switch-on at the end of 2023 has been coursing power in real-time back and forth across the North Sea between the British and Danish grids, as a more relevant comparison.

“Viking Link transports power between the UK and Denmark whenever and in whichever direction it is needed [to meet demand]. It works, no question,” he said. “ So what if we ‘stretch’ such a cable to five times its length to get [NATO-L]?”

HVDC specialists including Cornelis Plet, head of HVDC technology at DNV, an international assurance and risk management company, believes that while laying any power cable more than 1,000 kilometres long would be “uncharted territory for the industry, there are no major red flags” with the NATO-L project.

“This is a major engineering challenge to be sure, but from our work on this topic we didn’t spot any impossibilities or real ‘showstoppers’,” he said, speaking with Canada’s National Observer. 

Today, because of a number of factors, including the “material strength” limitations of the insulation used to minimize power loss from a cable’s copper-wire core, 2 GW is as big as an offshore line can be, resulting in NATO-L needing to bundle three together to get the transmission capacity it needs. 

This is not without its advantages in fact, Plet noted. Having a trio of cables, he said, would afford “a kind of back-up” should one of the lines fail and so “overall system availability would be higher”, improving the project’s economics.

The “real beauty” of NATO-L though, according to Richard Black, director of policy at Ember, a research consultancy, which recently published a report on transatlantic power transmission, lies in the international time-zones the line would bridge.

“Interconnection would help immensely with both demand and supply variability, really smoothing out grids on both sides of the Atlantic,” he told Canada’s National Observer. “Europe is asleep when North America is still awake and vice versa, so contrasting power demand profiles match up well too.”

Demand and supply stabilizer

Segalen adds the time difference between the two grids could create a “harmony based on each understanding the other’s peak [demand] periods and times when generation is surplus” to demand. 

This balancing of grids would be especially important for such a long-distance offshore interconnector, which, according to DNV calculations, could see power losses as high as 13 per cent - compared to around four per cent for onshore HVDC lines, deeply impacting the economics of the electricity through the line. 

To progress the megaproject, a NATO-L foundation for “people, nations and institutions” is being set up to raise the massive amount of capital required, said Segalen, with expectations the powerline could be financed in eight years and operational three to five years later.

Meeting the fast-growing demand for clean energy in Europe and North America - Canada expects to see electricity demand more than double by 2050 to meet government net-zero emissions targets - will “future-proof” NATO-L, he said. 

So too will construction of the next wave of power-hungry data centres, Segalen added, “which will add who knows how much to the demand-side” of the energy system. 

The founders of the NATO-L project view it as “not just an infrastructure project, it would be a symbol of cooperation between democracies.” It’s an identification that will resonate loudly with Canadians as the country’s trade war with the US has led to calls for greater energy sovereignty and independence from its southern neighbour.

“As North America electrifies, Canada was going to have increased interconnection within the country and with the US. One of those is off the table, so Europe suddenly does look like a very good bet,” said Black. “And the political relations between Canada and Europe are already excellent.” 

Segalen added: “This project is not a counterthreat to the US. It is more about diversification of markets. There is no enemy. Only energy security for Canada and Europe, economics, jobs, and market internationalization. There is an opportunity here to stop playing defense in the global energy landscape and start playing offense.”

Canadian offshore wind export?

If NATO-L gets built as planned, the timing might be ideal for Canada’s burgeoning east coast offshore wind sector. Though a lead-off 5 GW offshore wind auction is slated for later this year, the sector faces an uncertain future without a clear  “route to market” for future power generation due to the sparse industrial and residential demand in the Maritime provinces.

Until now, the major cities in the US northeast — New York, Boston, Philadelphia — were the likeliest destinations for this energy, but President Donald Trump’s renewables moratorium has cast a pall over this plan. Meanwhile, the early promise of using offshore wind to produce green hydrogen for shipment into international markets has not materialized as quickly as once forecast. 

Until now, the major cities in the US northeast — New York, Boston, Philadelphia — were the likeliest destinations for this energy, but President Donald Trump’s renewables moratorium has cast a pall over this plan. Meanwhile, the early promise of using offshore wind to produce green hydrogen for shipment into international markets has not materialized as quickly as once forecast. 

The European side was well-equipped already, he added, pointing to the numerous energy islands - offshore hubs for collecting and distributing electricity generated by wind farms at sea - that are currently under development. 

Black thinks that in the long run NATO-L transforming Europe into an export market for Canadian wind and hydropower could mean interest in green hydrogen production — for which Canada has three memoranda of understanding with Germany — wanes further. 

“Once the economics of a project like a transatlantic interconnector become clear, we may see the market for green hydrogen shrink,” he said.

Given the pace at which the world is electrifying, with record installations of 560 GW of renewables last year, according to the International Energy Agency,  interconnectors will be edge-pieces in the global energy transition puzzle.  

“NATO-L will eventually get built —  even if not by us —  because it answers all the questions about energy supply, energy sovereignty, energy security in Canada and Europe,” said Segalen.

“The bigger the grid, the better for everybody. Good for all countries involved, good for consumers, good for society.”

From: The audacious plan to build a giant green powerline under the Atlantic | Canada's National Observer: Climate News