Fundy Isles – After a nitrogen gas leak was detected in a portion of subsea cable, it was taken out of service and power has been supplied to Grand Manan, Campobello and White Head by generator for several days.
The power source for Deer Island, Campobello and Grand Manan comes from a 69 kilovolt “gas insulated” cable which means nitrogen is pressurized within the cable that acts as an insulator to protect the power line from moisture and water, explained NB Power communications officer Marc Belliveau in an email.
Crews noticed a drop in the gas pressure Jan. 17 in the section of cable running between Deer Island and Campobello. NB Power enlisted the help of UNB engineers,
Canadian Seabed Research, subsea cable experts, the Fundy North Fishermen’s Association as well as divers to try to find the source of the leak.
Using technology like sonar and GPS, these experts found the location of the leak Jan. 22 which was approximately 400 metres off Campobello.
After assessing the situation, NB Power has decided to re-energize the cable, as an undersea operation to repair the cable casing is not warranted at this time, said Belliveau Tuesday.
“The amount of nitrogen gas exiting the cable casing is minimal and harmless. Nitrogen gas is 78 per cent of the air we breathe. The cable will be re-energized Wednesday between 4 p.m. and 5 p.m. and will require an outage for customers in Campobello Island and Grand Manan during that time.”
The Fundy Isles submarine cable was originally installed in 1978 and is nearing the end of its useful life so NB Power was proposing to install a new cable between Deer Island and Campobello, and Campobello and Grand Manan while existing cables remain in service. New cables will be rated higher than existing ones to allow for potential additions to future renewable energy projects.
“NB Power will work towards installing a new cable, which was already planned, faster than had originally been anticipated, pending regulatory approval,” said Belliveau. Public open houses were held in Grand Manan and Campobello last fall. This is part of the permitting process which also includes an environmental impact assessment.
It was originally anticipated work on the new cable will be completed by fall 2019 but the timeline will be updated as NB Power seeks regulatory approval.