The Mid-Atlantic and Midwestern United States could plug into growing Canadian clean power sources through a new underwater transmission line under a plan submitted to the National Energy Board (NEB).

Sponsor ITC Holdings started regulatory and service marketing processes by filing a formal project description for the proposed Lake Erie Connector. The line would be the first direct link between Ontario’s Independent Electric System Operator (IESO) and the U.S. network of PJM Interconnection LLC.

The plan calls for laying a pair of six inch-diameter high-voltage direct current (HVDC) cables, capable of transmitting 1,000 megawatts, across 107 kilometers (64 miles) of the bottom of Lake Erie between southern Ontario and northern Pennsylvania.

As a merchant connection, needing no direct government or consumer subsidies, “the project will capitalize on existing and projected energy market opportunities,” said ITC, an independent power line builder based in the Detroit suburb of Novi that bills itself as America’s energy superhighway.

The package includes a dramatic symbol of replacing old, polluting power supplies with clean sources. On the Canadian side, the route would start near the remains of a 43-year-old coal-fired generating station that was an environmental sore spot at Nanticoke on the Ontario northern shore of Lake Erie.

At its operational height in the 1990s and early 2000s, the Nanticoke complex stood out as Canada’s biggest single source of carbon emissions by burning 35,000 tons of coal per day to make steam for eight generators putting out 4,000 MW.

Under provincial and federal policies of phasing out coal-fired power across the country as generators reach the end of their mechanical lifespans, the Nanticoke site shut down in 2013. Four of the generators have been discarded. The last four are idle, in mothballs on “standby” as last resorts for peak demand periods. Firing any backup with coal is off limits. To restart, the plants would have to burn cleaner substitutes: natural gas or biomass.

In Ontario, the IESO serves a market going through continuing change under an ambitious provincial government clean-power policy that includes a feed-in tariff for passing on to consumers added costs of switching electricity sources.

In the United States, PJM is the regional transmission organization running power delivery and markets for an estimated 61 million consumers in 14 jurisdictions: Delaware, Illinois, Indiana, Kentucky, Maryland, Michigan, New Jersey, North Carolina, Ohio, Pennsylvania, Tennessee, Virginia, West Virginia and Washington, DC.

Before filing at the NEB for the Lake Erie Connector, ITC obtained permission from the Federal Energy Regulatory Commission to solicit potential service subscribers. The new line would be a long-range profit generator for power merchants, the project sponsor predicts in its Canadian documents.

“Due to differences in resource mix and other market dynamics in the IESO and PJM markets, energy price differentials have been substantial, demonstrating significant market opportunities,” ITC said.

“Nuclear, hydro and other renewable and low-carbon emitting resources in Ontario, compared to a mix of relatively higher carbon emitting coal and natural gas resources in PJM coupled with state mandated renewable standards and federal environmental regulations, are expected to sustain the price differential.”

The NEB filing set targets of starting work on laying the proposed Lake Erie Connector in 2016 and putting the link into service as of 2018. A power supply surplus is at hand in Ontario and will keep on growing during the construction period, ITC said.

By 2018, the mixes of generating capacity in Ontario and the target U.S. market for the new line are forecast to be sharply different.

In Ontario the market share of fossil fuel-fired power stations is expected to drop to 25%, all from burning natural gas or oil and zero from coal. Renewable sources, led by wind power but including spreading solar installations, are forecast to grow to 23%, while atomic power reaches 28% and hydroelectric sites are 22%.

In the PJM territory, the fossil fuels are forecast to retain strongly dominance. As of 2018, coal-fired generation is expected to retain a 22% share of supplies, while gas- and oil-burning stations keep 45% and renewable sources trail at 14%, atomic power holds 16% and hydroelectric stays marginal at 3%.

Although primarily intended for Ontario clean-power exports, the transmission service would be reversible, ITC says. AC-DC converters would be installed on both the U.S. and Canadian shores of Lake Erie, and each side would be capable of going both ways. Converters are essential elements of the new generation of high-efficiency DC transmission lines because AC remains the dominant current used by consumers.

No cost forecast is disclosed by ITC’s description of the Lake Erie Connector for the NEB. An early estimate by a Canadian renewable energy firm that originated the concept and sold the project to ITC pegged the link’s price tag as on order of US$1 billion.