Tidal

Tidal energy is one of Nova Scotia’s natural advantages and will form a key part of its suite of renewable energy resources. The Bay of Fundy is internationally recognized as the most suitable location for the development of a world class energy resource.

Tidal energy is based on lunar gravitation. A form of hydroelectricity, tidal energy is intermittent, but it is predictable and reliable. The utilization of the tides for energy is not a new idea. Tidal mills were built in Britain, France, and Spain as early as the 12th century.

Applications of Tidal Energy
Conventional tidal applications make use of estuaries or lagoons where a barrier can be constructed. Known as “barrage plants”, turbines are installed similar to a hydro-electric application and energy is harvested as the tides flow through the turbines. The Annapolis Royal site uses this type of technology at a capacity of 20W. There has been a 240MW site in operation in Brittany since 1966. The sites for this type of application are limited, as they require natural ponds and estuaries or environmentally damaging man-made dams and lagoons.

Newer technologies for harvesting the tides resemble wind turbine applications and are placed directly in the ocean. Because water is much denser than air, a single turbine can harvest a considerable amount of energy. Commercial entities are developing competing models for retail into a rapidly developing market. Several installations are in development even as prototypes of machines compete for primacy. A 300 kW machine in Norway was the first grid-connected turbine. In 2007, a 1.2 MW machine was installed in Northern Ireland.

Costs are Coming Down
Tidal turbines are still extremely expensive, but they are moving quickly toward commercial viability. With so many corporations and entrepreneurs competing to develop turbines, the price of harvesting tidal energy should tumble in the short –to-near term. Compared to the cost of fossil fuels, we can be sure that tidal energy will provide a reliable ‘low-cost’ alternative and a key part of Nova Scotia’s energy mix.

Potential Resource
The Canadian Encyclopedia estimates that the aggregate total capacity of all potential tidal-power sites in the world is about one billion kilowatts, with an expected electrical-energy output of 2-3 trillion kilowatt-hours annually.

Nova Scotia is fortunate in its abundance of this resource. As the world demand for clean energy grows, our province finds itself in the enviable position of enjoying two of the world’s best sources of two of the most productive renewable energy sources: wind and tidal.

Research from US-based Electric Power Research Institute identifies the Bay of Fundy as perhaps the most potent site for tidal power generation in North America. (Reference: Electric Power Research Institute, “Ocean Energy: Nova Scotia Site Survey Report”, Oct 2, 2006.)

One-hundred billion tons of seawater flow in and out of the Bay of Fundy each day - more than the combined flow of the world’s freshwater rivers. (Nova Scotia Department of Energy, Web site Information on Tidal.)

The 25-30 ft tidal variations of Passamaquoddy Bay (Bay of Fundy) have the potential of between 800 to 14,000 MWe. (Reference: Ocean Energy Council, Tidal Energy FAQ.).

Finally, according to the Consultation Document for the Energy Strategy, when fully developed, new in-stream tidal technology has the potential to generate 300 megawatts of green, emission free energy from only two locations in the Bay of Fundy - enough energy to power close to 100,000 homes.

The Case for 100% Renewable in Nova Scotia

Read more about the case for 100% Renewable Energy in our 2008 submission to the Department of Energy, Renewed Energy Strategy + Climate Action Plan consultations. Download 2008 Submission Document.