For a couple of weeks, Grand Manan, Campobello and White Head islands were powered by the Grand Manan generating station after damage to the undersea cable occurred on January 17. The cable casing was breached, possibly by a scallop dragger. The casing is filled with nitrogen as an insulator, and gauges showed a drop in pressure and more nitrogen being used. The power cable was shut down, and customers were transferred to the island generating station. Outages on Grand Manan and White Head lasted between one and three hours as the transfer was effected.
"It's fairly straightforward," says NB Power Media Relations spokesman Marc Belliveau and not as complicated as other outages they have had, although they were surprised to have a problem with the "very reliable" cable, which was installed in 1978 and has had "very little problem in all the time it's been there." He says they have seen footage of anchors snagging the cable without damage.
NB Power enlisted the help of University of New Brunswick engineers, Canadian Seabed Research, subsea cable experts, the Fundy North Fishermen's Association and divers using sonar and GPS to locate the leak, which turned out to be 400 meters off the coast of Campobello toward Deer Island. Belliveau says, "Sonar is able to detect changes in the ocean bottom; they are so precise they can find fish. Our team actually was able to increase the nitrogen pressure and on a calm day on a boat were able to see bubbles at the surface after having passed over the cable area with sonar. A remote-controlled underwater vehicle with a camera followed the cable and found the precise area where bubbles were coming out of the pipe." He notes that 78% of the air people breathe is nitrogen and says there is "no threat to wildlife, sea life, fishing activities or the public," but the leak was reported as required to both federal and provincial departments of the environment.
Grand Manan Mayor Dennis Greene was in "constant touch" with NB Power and says it took 100,000 litres of diesel at a cost of $100,000 per day to run the island generator. This amounts to four truckloads per day from the mainland; Greene says he wasn't initially too concerned about the arrangement until residents began asking what might happen if the ferry couldn't run. Someone pointed out that the island was "dependent on three diesel engines," two on the ferry plus the generating station. Greene says the island's agreement with NB Power has been that there would always be backup power for Grand Manan; however, the generating station is the backup, and it has been suggested "we need a backup for the backup."
After assessing the situation, Belliveau says NB Power decided "to re-energize the cable, as an undersea operation to repair the cable casing [using a sleeve] is not warranted at this time. The amount of nitrogen gas exiting the cable casing is minimal and harmless." The work was originally scheduled for January 31 but was postponed until February 1 because an insulator on the transmission line had to be replaced. He says they don't anticipate further trouble.
Although it "took a while to get off on the right foot" in his conversations with NB Power representatives, Greene says they had good communication and he was kept updated. He says there would be five days of reserve fuel if the ferry didn't run, but he would like to have other alternatives. They have discussed the possibility of getting power from Maine through Campobello or providing another generator for the islands. He thinks that in the future "we will meet with [NB Power] and pursue other options that we think are in the best interest of Grand Manan."
The undersea cable is scheduled to be replaced, and Belliveau says at least this breach had good timing since they are in the planning and regulatory approval process; open houses were held on Grand Manan and Campobello in September. NB Power's website states that the new cables will be "rated higher than the existing to allow for the potential addition of future renewable energy projects." No decision regarding the removal of the old cable has been made, as NB Power is assessing options. An environmental impact determination is expected this spring. The timeline includes a six- to eight-month manufacturing time, with land‑based work scheduled to start this year, cable installation in the summer of 2019 and service beginning that fall. Now, Belliveau says, NB Power will work toward finishing the project sooner. Greene is hopeful for the coming summer, but Belliveau notes a revised timeline will depend on regulatory approval.