Northern Pass officials plan to appeal the New Hampshire Site Evaluation Committee's 7-0 decision on Feb. 1 to deny the project's application for a 192-mile, $1.6 billion transmission system that would deliver lower-cost Canadian hydropower through New Hampshire and into neighboring Massachusetts.
The surprise vote came in the early part of a 12-day deliberation period that followed a 27-month review process.
The Northern Pass Transmission Line Project was to have been under construction as early as April, with a 2020 completion date.
But that timetable is uncertain now after the committee concluded Northern Pass failed to meet its legal burden of proving the transmission line would not "unduly interfere with the orderly development of the region."
The hydropower to be delivered by the project to New England’s power grid would come from Hydro-Québec’s hydroelectric plants.
Northern Pass spokesman Martin Murray said in a statement that the project’s developers were "shocked and outraged" by the committee's vote, adding Northern Pass would seek reconsideration of the SEC's decision and review "all options for moving this critical clean energy project forward."
Pamela Monroe, the SEC's administrator, said in a Feb. 5 email that the committee "will be issuing a written decision memorializing the decision of the committee" at some point, although she could not estimate when that might be.
Once the written decision comes out, Northern Pass will have 30 days to file for rehearing, she said. "The committee will then need to convene to make its decision on the motion for rehearing."
Northern Pass also could appeal the committee's decision to the New Hampshire Supreme Court, but Murray did not comment on that potential option.
During last week's SEC meeting, committee member Patricia Weathersby, an attorney, appeared reluctant to halt the proceedings so early in the 12-day deliberation process.
"I'd love to be done. I think everyone here would love to have this - a final decision on this," she said, according to an official transcript of the meeting provided by Monroe. "But the lawyer in me says we should be sure to dot all our 'i's' and cross all our 't's'."
Weathersby, who ultimately voted with her colleagues against the project, acknowledged the panel had made good progress in its deliberations. "It's gone quicker than I think, I know, more quickly than I thought it would go."
The Northern Pass project recently was chosen by Massachusetts to advance to contract negotiations under a procurement issued in 2017.
The solicitation process was the result of a law passed in 2016 by the Massachusetts Legislature to provide new sources of clean energy by 2020.
Northern Pass was one of dozens of projects proposed in response to the solicitation. The Northern Pass Transmission Line Project bid was submitted by Eversource and Hydro-Québec.
Eversource is New Hampshire's largest electric utility, serving more than 500,000 homes and businesses in 211 cities and towns.