An East Coast project is harnessing the power of the world’s biggest tides. Will it succeed where others have failed?

HALIFAX – Every six hours, 160 billion tons of seawater enter – or leave – the Bay of Fundy. That’s more than four times the flow of the Amazon, the Nile and all other freshwater rivers in the world… combined.

In some places, the tide will rise more than 16 meters. When it retreats, it can expose the ocean floor for up to five kilometers.

These tides – the largest in the world – have made the bay an attraction for tourists from around the world, who flock in hordes to walk the newly exposed ocean floor or kayak in its rising waters.

But in the eyes of some, it is also a vast, untapped source of potential green energy that no one has yet been able to fully harness.

That could soon change as, for the first time, a company – using a 30-meter-long, 30-meter-wide floating turbine platform – has managed to convert the energy of the world’s largest tidal waves into electricity for Nova Scotia’s power grid. .

And that could open the door to a predictable, renewable supply of energy on any stretch of coastline with a significant tide — an eye-watering prospect for a country that has oceans on three sides.

Edinburgh, Scotland-based Sustainable Marine announced this week that its PLAT-I 6.40 tidal turbine floating platform had connected to the Nova Scotia grid from its Grand Passage site near the southern tip of Digby. Neck, in the southwest of the province.

At peak flow, it is capable of pumping 420 kilowatts. That’s enough to supply 420 homes, more than enough for the entire population of neighboring Brier Island.

“This is the first time that energy from a system like ours is actually going into a grid and being used by people and helping to end Nova Scotia’s coal habit,” said Jason Hayman, CEO of Sustainable Marine.

“The Bay of Fundy is just an amazing tidal energy resource. It’s a massive, massive resource, but it hasn’t been technically feasible or practical until now to use it.”

Nova Scotia Prime Minister Tim Houston recognized the achievement as “a first in the history of Canadian tidal energy”.

“This project and others are positioning Nova Scotia as a global player in the tidal energy sector and are creating green technologies, green jobs, a cleaner environment and a predictable, renewable source of electricity for Nova Scotia residents,” he said. he in a statement shortly after the platform first supplied power to the provincial grid.

Fundy’s tides could, if harnessed efficiently, go a long way towards decreasing its dependence on coal-fired power plants and meeting its stated goal of having 80% of Nova Scotia’s electricity needs met by renewable energy by 2030.

This is a difficult task. Nova Scotia’s four coal-fired power plants supply 1,252 mW to the province, by far the majority of its generating stations.

There is a huge gap between the maximum power of 420 kW of one of Sustainable Marine’s platforms and, for example, the power of 620 mW of the largest coal plant in the province. But one of the highlights of the Sustainable Marine project is that the platforms are modular and scalable.

Each catamaran-shaped platform has six turbines, each looking a bit like the outboard motor of a speedboat. Like an outboard motor, the turbines can be tilted out of the water for maintenance. A turret on the platform allows you to orient yourself with the flow of the tide. Each platform can be linked to another to increase the amount of electricity generated.

Sustainable Marine's PLAT-I 6.40 tidal turbine floating platform is pictured in this undated brochure photo.  With six turbines and a maximum power of 420 kW, the platform can be connected to other platforms to transform the enormous tides of the Bay of Fundy into electricity.  Photo courtesy of Sustainable Marine.  /Toronto Star

The Grand Passage platform is a proof-of-concept test, Hayman said. When these trials are complete, this platform will travel north to connect to two more platforms on the Mine Passage at the Fundy Ocean Research Center for Energy (FORCE). Together, while environmental monitoring continues, they should be able to generate 1.26 megawatts from the tides.

But that’s just the tip of the iceberg, Hayman said. He said he predicts that in the future, floating turbines will be able to extract hundreds of megawatts of electricity from the Bay of Fundy.

On Passage de Minas alone, he said, the province could easily place 100 of the platforms without coming close to blocking the strait.

“The room is there, and the resources are there to make hundreds of megawatts and really have a really significant impact,” he said.

At the other end of the scale, smaller clusters, or even individual platforms, could generate electricity in coastal waters anywhere that has a tidal flow of around five knots. And that means it could serve smaller coastal communities – some of which may still rely on diesel generators for electricity.

In British Columbia, for example, the platforms could generate power for communities along the passage between Vancouver Island and the mainland, and further north along the coast, for communities along the Inner Passage between Port Hardy and Prince Rupert.

But before that happens, the platforms will face a battery of tests on FORCE. In addition to evaluating its feasibility as a renewable energy alternative, FORCE will study the potential effects of its turbines on marine life, marine noise and other environmental variables.

Hayman acknowledged that for the Sustainable Marine platform to achieve widespread use, there will have to be a level of acceptance from those who live in and around the Bay of Fundy.

“This is new technology and people need to be comfortable with it. If you are going to put things in the community backyard, they need to feel comfortable that it is safe, that there will be no adverse impact on wildlife or their livelihoods.”

If there is any skepticism, it is not without reason; Efforts to extract electricity from the tide have not been without failures, some of which still remain on the ocean floor.

In 2009, a prototype turbine that was on the ocean floor in Passagem de Minas was destroyed by the fast tides of Fundy, which can exceed 10 knots or 18 kilometers per hour.

And in July 2018, Cape Sharp Tidal connected a two-mW tidal turbine mounted on the ocean floor to the grid. But that venture was short-lived, ending when one of its owners, Dublin-based OpenHydro, declared bankruptcy the next day.

The turbine, which was damaged beyond repair just a few months after it was deployed at Passagem de Minas, is still at the bottom of the ocean.

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