Will the Bay of Fundy wash ashore Nova Scotia’s hidden energy potential?
The ocean currents that flow into the lakes and bays of Nova Scotia have tremendous potential to provide the coal-dependent east coast province with not only a source of renewable energy but also some potential relief from dependence on fossil fuels
Tidal power has been in commercial use since the mid-1980s, but the province has recently set out to explore new in-stream energy conversion technology, deployment of which could well position Nova Scotia as a world leader in tidal power generation. As Aimee Lorefice explains, combined with a recognized need for cleaner energy, the Atlantic province has caught the attention of industry and developers alike.
The Bay of Fundy, running between Nova Scotia and New Brunswick at the tip of the Gulf of Maine, has a tidal power capacity of about 2,700 megawatts (MW), 300 of which are deemed usable. A study last spring by a California research institute specifically cited seven key development areas in the Bay of Fundy, causing a stir at the desks of Nova Scotia bureaucrats and re-igniting investor interest. Since then, the province on April 12 released a regulations framework for investors and put $250,000 toward an environmental study to test the impact of in-stream devices.
And, if it can successfully capitalize on the reliable and predictable energy source, Nova Scotia stands to do well. But a lot of work has to be completed first. Before in-stream tidal power generation goes commercial, in-depth environmental studies must be conducted and new devices will have to demonstrate their resilience to the Bay of Fundy’s treacherous waters.
Scientists have explored Nova Scotia’s tidal power potential for decades, leading to many proposals and the development of the Annapolis Tidal Power Generating Station. Operating since 1984, and generating 20MW of power (enough to power about 6,000 homes), the Annapolis River plant is one of only three of its kind in the world. Northern France is home to the largest tidal power station (240MW) and Russia has a small unit in the White Sea. But this dated technology poses considerable environmental consequences and new devices show great potential.
The unit selected for testing by Nova Scotia’s power utility is a 12-diametre submersible device with an open centre and enclosed blades – a big step forward from the obtrusive dam and barrage structures that are otherwise used. While highly expensive – a one-megawatt turbine would cost $12 million – Acadia University biologist Graham Daborn says the proposed open centre turbine, which has a hole in the centre for fish and water to pass through, may have less impact on fish and invertebrates. However, myriad environmental concerns attend any structure that blocks ocean water movement because of its effect on the sea floor and on the natural flow of tides.
“Fish mortality rates are a serious concern,” Daborn says. “There is a concern of destabilizing the sea bottom and there is a real concern that if you try to take out too much energy one of the effects is to change the regime
of the tides.”
And one environmental concern gives way to another. Rising oil prices and mounting concerns about the overuse of fossil fuels add clout to the exploitation of alternative energy sources. Renewable energy options are particularly attractive in Nova Scotia where fossil fuels, predominantly coal, represent 85 per cent of the electricity mix, according to Nova Scotia Power Incorporation (NSPI) figures.
“Interest (in tidal power) has been generated four times over the last 100 years,” says Daborn, who has studied tidal power development in the Bay of Fundy for 30 years and co-edited a number of books on the topic. “And each time the catalyst was a rise in oil prices and decrease in supply.”
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