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Engineering Marvel: Ship Begins Laying Massive Power Cable Connecting N.L., N.S.

April 27, 2017 5:36 PM | The Canadian Press

By Michael MacDonald, The Canadian Press

Nexans Skagerrak

A cable reel aboard the cable-laying vessel Nexans Skagerrak is shown in Argentia, N.L. in a handout photo taken earlier this month. Late Wednesday the ship started laying 170 kilometres of electricity cable between Cape Ray in southwestern Newfoundland and Point Aconi in northeastern Cape Breton as part of the $1.6-billion Maritime Link project. (THE CANADIAN PRESS/HO)

HALIFAX – Somewhere off Newfoundland’s southwest coast, a Norwegian ship has begun spooling out a massive, thick cable that will connect the island with Nova Scotia, a 170-kilometre voyage that, once completed, will create North America’s longest subsea electricity link.

The cable-laying ship CS Nexans Skagerrak started rolling out the black-and-orange cable across the Cabot Strait late Wednesday, a process that began just off Cape Ray, N.L., where the cable has already been anchored.

The slow-moving ship, operated by Nexans SA of France, is expected to arrive off Point Aconi, N.S., by May 8, if the weather holds.

“It looks like we’ve got a pretty good weather window to work with,” said Rick Janega, president and CEO of Emera Newfoundland and Labrador, a subsidiary of Halifax-based Emera Inc.

A second cable is expected to be deployed by early June. Final connections and testing are expected to wrap up by the end of this year.

The two cables, each the width of a two-litre pop bottle, will be part of the $1.6-billion Maritime Link project, which will enable Newfoundland and Labrador’s Crown-owned Nalcor Energy to provide privately owned Nova Scotia Power Inc. with renewable energy from the Muskrat Falls hydroelectric project in Labrador.

The cables will also enable the two provinces to trade and sell electricity. Each can carry up to 250 megawatts of electricity.

Together, they weigh about 11,000 tonnes, which is more than the Eiffel Tower. Their copper conductors are protected by 13 layers of various types of armour, insulation, fabric tape and a lead-alloy sheath.

The cables will rest on the ocean floor at depths up to 470 metres. Closer to shore, they will be buried under sand or rock at depths of 200 metres or less.

“Deeper than that there isn’t much risk of marine activity, whether fishing or anchors from vessels,” Janega said.

At 170 kilometres, the Maritime Link will be twice the length of what is now North America’s longest subsea electricity cable, which crosses San Francisco Bay.

The world’s longest submarine electricity cable, the NorNed project, links the grids of Norway and the Netherlands. It is three times longer than the Maritime Link, at 580 kilometres.

“They’ve been doing these cables for 50 years in Norway and Sweden, and in the Netherlands,” Janega said. “We know it’s proven technology.”

The Maritime Link, most of which will be paid for by Nova Scotia Power ratepayers, remains on schedule and on budget, Janega said.

“We’re doing everything we can to meet both of those objectives,” Janega said. Things are looking pretty good.”

Emera says the link will help meet Canadian federal regulations requiring a 50 per cent reduction in coal emissions by 2030 and Nova Scotia regulations requiring 40 percent renewable energy by 2020.

The project stands in contrast to the Muskrat Falls project itself, which is two years behind schedule and about $4 billion over budget at $11.7 billion.

Stan Marshall, Nalcor’s CEO, has agreed that the project has become a “boondoggle,” saying it will remain an economic burden for Newfoundland and Labrador for at least four years.

Muskrat Falls was supposed to start producing power later this year, in time to take advantage of the Maritime Link, but the delay means electricity from there won’t arrive in Nova Scotia until 2020 at the earliest.

Still, the Maritime Link won’t sit idle. Nova Scotia Power, another subsidiary of Emera, is expected to supply electricity to the island of Newfoundland to enable the province to shut down its oil-fired Holyrood generating station near St. John’s, Janega said.

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