Massive New Grid Corridor Could Connect Offshore Wind to Nova Scotia, New England

A new offshore power transmission corridor could eventually connect wind turbines off the Nova Scotia coast and in the Gulf of Maine to power grids and green hydrogen facilities in the Maritimes and New England, under a preliminary scenario published last week by a seven-member business coalition.

A synopsis of a white paper produced for the New England-Maritimes Offshore Energy Corridor (NEMOEC) coalition by Toronto- and Boston, MA-based Power Advisory LLC envisions a 2,000-megawatt project that would cost US$6 to $8 billion to build. It would connect to power grids in Nova Scotia, where the province is planning leases for 5 GW of wind by 2025 to support green hydrogen development, and Massachusetts, which has set its sights on up to 30 GW of offshore wind by 2050.

The paper lays out one possible plan for a phased, modular project that could begin with high-voltage direct current (HVDC) connections to wind farms off Nova Scotia’s Sable Island or south of Halifax, then potentially extend to New England electricity markets and offshore wind projects at a later date.

Coalition representatives will be presenting the project at a May 11 webinar hosted by Net-Zero Atlantic.

Reaching Out Early

The NEMOEC coalition includes companies based in Halifax, St. John’s, Toronto, Houston, and three countries in Europe. Coalition spokesperson Abby Watson, president of Philadelphia-based Groundwire Strategies, said the connection to New England comes from coalition member Total Energies SBE US, a new partnership between French state fossil TotalÉnergies and Simply Blue Group that has been actively involved in offshore development in the Gulf of Maine.

Watson said coalition began meeting with policy-makers, environmental groups, and other stakeholders in Atlantic Canada and New England in December to make sure the initial white paper addressed their most important questions. That kind of listening and outreach is an important part of the process, she added: “Recognizing that this was clearly going to be a big-tent effort, we were going to need a lot of buy-in from all sorts of stakeholders to make it successful.”

Brendan Callery, manager of resource integration analytics in Power Advisory’s Toronto office, said a key purpose for the white paper is to advance those conversations and try to entrench the basic concept of an international transmission intertie that connects two different electricity supply regions, and possibly two demand regions if projects from the Gulf of Maine eventually join in.

“There is no timeline” for actual project development, he added, and “there are still some assumptions and caveats and different directions a project proponent could take this.” For now, “it’s just taking a high-level view and longer view,” building on experience in Europe with setting common design standards for offshore wind projects that can expand in a modular way over time.

Less Gas, More Reliable Grid

The synopsis acknowledges the “complexities associated with permitting a multi-jurisdictional HVDC transmission line,” but sees the project delivering a series of economic and environmental benefits worth US$620 to $780 million per year. They include:

• The connection itself between offshore wind farms and onshore grids;

• Reduced reliance on natural gas, particularly in New England, leading to less fuel security risk, more stable prices, and lower greenhouse gas emissions;

• Better grid reliability;

• Less need for onshore transmission upgrades to deliver electricity farther south in New England;

• Use of HVDC lines that allow for longer subsea cables and give developers a better chance of locating landing points in less environmentally sensitive areas;

• Reduced impacts on local fisheries, with fewer transfer points to the mainland and nearly 50% less trenching needed in marine ecosystems;

• More opportunity for wind developers to sell their product where it will generate the highest revenue.

It was important to lay out those gains in detail, the synopsis explains, since they accrue to a variety of different parties. “With transmission benefits more diffuse, there’s a greater likelihood of reduced transmission investment,” it states. “By quantifying the benefits, those values can be recognized in the cost allocation process or when the investment decision is made.”

The white paper says planning and permitting for an offshore transmission corridor will take two or more years at the federal level in the United States, four to five years at the state level, and two to three years in Canada. But regulation of offshore clean energy projects is an area where Canadian regulators are running behind their U.S. counterparts.

“This is something they’re looking into just now,” Callery said, and that means an opportunity to help shape and form the eventual regulations before they’re set in stone. “It was good timing to get this out, to be a part of the process and see what lessons we can learn from the U.S. and Europe on how to make smart, long-term decisions,” all while acknowledging that “we don’t quite know what this project will look like in its final form.”

The next step, Callery said, is to track down funding for a full transmission study to assess project costs and benefits in more detail, refine the numbers, look more closely at possible business models for the line, and get more specific about the corridor route, at a time when power utilities across North America and Europe are in desperate need of more transmission capacity. “It’s not just about developing renewables,” he said. “We need to build a lot more wires to go along with that, and the more options on the table, the better.”

He cast grid infrastructure as the “essential bridges and roads and railways that are necessary to maintain the level of reliability we’ve become accustomed to as we shift our systems towards clean energy.” With New England facing long-standing issues with its natural gas network, “there’s a reliability benefit that is very important,” and a “massive shift about to take place in a transition to a fully green grid, or a grid where gas has a much lower profile.”