Several months after receiving approval from Nova Scotia’s Department of Environment to deploy two 16-metre, 1,000 tonne turbines in the Bay of Fundy’s Minas Passage, Cape Sharp Tidal has finally submerged the first of the OpenHydro Open-Centre 2MW turbines at the Fundy Ocean Research Centre for Energy (FORCE), near Parrsboro.
Cape Sharp Tidal plans to connect the turbine to the power grid in the coming days via FORCE’s subsea cable, which during the next several weeks will deliver Nova Scotia’s first in-stream tidal energy to the province’s power grid.
The turbine was towed on a barge from West Bay to the FORCE site on Monday morning, and then lowered to the sea floor in a four-hour operation during an ebb tide.
Cape Sharp Tidal is a joint venture between Nova Scotia utility Emera Inc. and OpenHydro, a tidal turbine manufacturer owned by French company DCNS.
The deployment follows months of delay for environmental review and an injunction request filed by the Bay of Fundy Inshore Fishermen’s Association, challenging the approval of Nova Scotia’s Environment Minister over concerns regarding the project’s possible impacts on sealife.
At the end of October, the Nova Scotia Supreme Court rejected the Association’s request for an injunction to prevent the installation of the turbines until after their judicial review application is heard on February 1, 2017.
Water moving from the outer Bay of Fundy into the smaller Minas Basin can reach peak surface speeds of five to six metres per second and rise up to 17 metres vertically, the height of a five-storey building.
Tides in the Bay of Fundy push more than 160 billion tonnes of water twice a day, which is more than four times the combined flow of every freshwater river in the world.
If that power could be harnessed, it would provide up to 60,000 megawatts (MW) of energy, from which approximately 2,500 MW can be extracted without significantly impacting the marine environment.
Nova Scotia’s Marine Renewable Energy Strategy articulates an objective of harnessing at least 300 MW of in-stream tidal energy after 2020, which is approximately 10% of Nova Scotia’s peak energy demand.
But installation of turbines for use in the Bay of Fundy has been a long trial-and-error process that has been defeated by the massive power of the bay, which can easily crush equipment.
Back in 2009, OpenHydro and Nova Scotia Power tried to deploy a one-megawatt turbine in the Minas Passage, but currents in the Bay are so powerful that the 12 two-metre long blades developed by the company and attached to the 400 tonne turbine simply snapped off.
That humbling failure sent engineers and designers back to the drawing board to build the turbines that are being deployed now.
There is no timeline yet for deployment of the second Minas Passage turbine.
When the two turbines are functioning together, they will represent North America’s first tidal array connected to an electrical grid.
In 2015, FORCE deployed two underwater monitoring platforms to facilitate real-time data collection from the Minas Passage, measuring currents and turbulence, marine life activity, noise level, and seabed stability.