外流影片

Along the craggy coast of southwestern Nova Scotia, the rocky narrows of the Digby Gut connect the with the Annapolis Basin. The treacherous tidal currents that make the Gut a risky spot for sailors also make it an ideal spot for researching ways of harnessing tidal energy.

In a three-year, $3.3 million research project, of Acadia鈥檚 Department of Mathematics and Statistics is investigating the Digby Gut and two otherchannels as potential sites for underwater turbines to generate electricity. Digby Neck is a small peninsula that lies alongside mainland Nova Scotia in the Bay of Fundy.

The project will assess the sites on their greatest energy potential, but it will also consider the engineering, construction, and operational costs associated with different technologies.

Called 鈥淩educing the cost of in-stream tidal energy generation through comprehensive hydrodynamic site assessment,鈥� the project involves other Acadia departments and five partners, including and the .

Funding of $1.6 million will come from Natural Resources Canada through its 2012 ecoEnergy Innovation Initiative competition.

In simple terms, Karsten鈥檚 part of the project is to use mathematical modelling to figure out how much power is available at the three sites, how much electricity can be generated using turbine technology, and how extracting power will change the tides. In short, it will define the opportunity to develop tidal power there.

Industry partners

The three industry partners are , , and .

Fundy Tidal is owned by community members in the Digby Neck area. 鈥淭hey鈥檙e the only company in Nova Scotia that has the right to sell tidal power to Nova Scotia Power right now,鈥� says Karsten, 鈥渁nd they have the right to do this in the three Digby Neck passages.鈥�

Dynamic Systems Analysis, Halifax, engineers marine structures and cabled systems in the ocean and is able to show how a turbine will survive and react to the tidal flows. Clean Current Power Systems is a Canadian company that develops river and tidal turbines to produce electricity with minimal environmental impact and zero greenhouse gas emissions.

Each partner is critical to the project, Karsten says. 鈥淲ith this type of project, it had to be university and industry in partnership to do the research, but also to tackle an applied problem with the goal of generating electrical power at the end of it.鈥�

Modelling the tides

Using computers and to predict how fast the water is moving at a given location, Karsten and his undergraduate students are modelling the tidal flow. With accurate models, they can identify the best places to site turbines. From there, they can predict how much power the turbines would generate if placed singly or as a large array, or farm.

The final task is to identify the impact turbines would have on the flow of the water and, ultimately, on the tides and local ecology.

鈥淲hen the water flows through the turbine, it slows down,鈥� Karsten says. 鈥淭hat鈥檚 the power you鈥檙e taking out. And if you put many, many turbines in, the slowing down of the water is going to change the tides.鈥�

A significant slowing of the water would have two main effects. First, it would change how much electricity would be generated if more turbines were installed. Second, it would affect the plants and animals that depend on the mud flats of the intertidal zone, including marine life and migrating birds.

鈥淲e鈥檙e trying to make sure we鈥檙e always balancing the possible benefits of generating electricity from the tides with the possible impacts on the environment,鈥� Karsten says.

Karsten鈥檚 students have done the bulk of the work developing the numerical models. One student is now looking at the potential change in area of the mud flats in the Annapolis Basin. Before any decisions are made to install turbines, the project鈥檚 environmental impact will be assessed.

Acadia鈥檚 location and people

Acadia鈥檚 location on the Bay of Fundy makes it a natural place to work on tidal projects, Karsten says, but the people here are just as important.

鈥淔or a small university, we鈥檝e got a core of researchers here working on tidal energy,鈥� he says. 鈥淲e have formed the with the mission of advancing knowledge of tidal energy that respects the environment and promotes socioeconomic prosperity.鈥�

The Institute includes from Biology for the environmental work; J from Recreation Management and Community Development, who鈥檚 looking at how the communities around the Bay of Fundy will be affected;  and  from the School of Business, who鈥檚 looking at the economic side of the project.

The involvement of students has been vital in getting the research done, Karsten says, but also because he can teach this project in the classroom.

鈥淲e鈥檝e tried to focus on making our research useful to the development of tidal energy, to answering the important questions about tidal energy,鈥� he says. 鈥淎nd I think a large part of that is being at Acadia. We do this every day in our classrooms.鈥�

-30-

For more information: