Marine Renewable Energy | WWF-Canada
	© Sarah Saunders / WWF-Canada

Marine Renewable Energy

The power of the tides

Climate change impacts oceans by raising temperatures and acidifying ocean water worldwide. Warmer temperatures are already shifting some marine species toward the North and South poles, and destroying those, like corals, that can’t move. Warmer waters and an increase in sea-ice melt have led to rising sea levels and more frequent and intense storms that are changing coastlines and damaging infrastructure. These changes are impacting marine species, and all those who make their living from the ocean. In some cases, entire nations are under threat.
An immediate and massive transition to renewable energy sources is the single most important step we can take to slow climate change and its impacts, thereby safeguarding our rich marine ecosystem. WWF-Canada is committed to seeing Canada use 100 per cent renewable energy by 2050.
In order to do this, new habitat-friendly renewable energy sources must be developed. Canada has the longest coastline in the world and some of the world’s highest tides, giving habitat-friendly marine renewable energy, including tidal power, an important role.

Untapped potential

What is tidal energy, and how does it work?

The tides, pulled by the gravity of the moon and the sun, ebb and flow with predictable regularity. Generating energy from the tides makes tidal energy a reliable, renewable energy.
Power from the tides is similar to wind – with water moving the turbine blades, instead of air. Energy from the tides can be captured in two ways: from the speed of tidal currents (known as in-stream tidal) and from the rise and fall of the tides (tidal range).

WWF-Canada supports habitat-friendly renewable energy projects that have minimal impacts on the world around them. In-stream tidal and tidal range projects use very different types of technology, and have vastly different impacts on the environment.
In-stream tidal energy versus tidal range

The in-stream tidal energy industry is in its infancy, with technology being tested to see if electricity can be safely and reliably produced. To date, in-stream tidal energy turbines have shown minimal impacts on the environment. However, only single turbines have been tested. In-stream tidal uses free-standing turbines, which can be removed should unacceptable impacts be seen.
Tidal range projects, similar to dams, wall off water to generate electricity. Tidal range projects, such as barrages and lagoons, can block the movement of boats and migrating species. WWF-Canada is not supportive of tidal range projects because of their long-term and potentially large-scale impacts on the environment.

Cautionary support

We need to exercise caution with in-stream tidal energy development to ensure it does not harm species or habitats, particularly as we move to the commercial stage.  

WWF-Canada’s involvement in the early stages of some projects has already mitigated potential negative impacts of in-stream tidal energy; for example, by ensuring that environmental considerations were added to Nova Scotia’s Marine Renewable Energy Act prior to the launch of the Fundy Ocean Research Center for Energy.
Given the excellent tidal energy potential around Canada, WWF-Canada recommends that in-stream tidal energy technologies be tested and eventually deployed at both large and small scales, but under the clear understanding that any impacts on marine ecosystem integrity and biodiversity will be short-term, reversible and effectively mitigated through appropriate locations, design and construction of turbines with stringent environmental monitoring programs and adaptive management plans in place.
We support the development of a clear regulatory framework, to ensure nothing is overlooked in the approval process. Development in this sector should proceed in an incremental and precautionary manner, erring on the side of caution to prevent negative impacts to species and their habitats.


WWF Marine Renewable Energy Reports