Tidal Power in Canada
The majority of the Bay of Fundy sits within Canada and some of the highest tidal flows are seen in the northern most regions of the bay. So, Canada has long explored the idea of using these resources to generate electricity. The first study was commissioned in 1977 by the federal government of Canada and the provincial governments of New Brunswick and Nova Scotia.
The second commercial-scale tidal barrage system ever built was constructed at Annapolis Royale in Nova Scotia in 1982. Annapolis Royale is a small town on the western side of Nova Soctia with a small bay. The tidal range in the bay and small scale of the installation made it an ideal site for early testing of tidal barrage technology. The barrage is capable of 16 megawatts of output at peak and utilizes a STRAFLO turbine, a type of Kaplan turbine.
The Annapolis Royale Generating Station highlights some of the dangers of barrage systems to the environment as it has twice been harmful to Humpback whales. The first incident was in 2004 and involved an adult whale that swam through an open gate as the tide was coming in. The whale was trapped for several days before finding its way out and though it did not suffer any permanent damage, it could have easily died due to lack of food had it not escaped. The second incident occurred in 2007 and involved a juvenile whale. This time the whale was killed when it followed a similar pattern as the first and was trapped for too long.
One the other side of the bay from Nova Scotia is New Brunswick, which boasts the world’s highest intertidal range. In the L’Etete Passage, the tide rises 53 feet from its low point, which is the sea floor. This massive range makes the area highly attractive for tidal power.
You may think that a barrage would be the system of choice in this area, but the damage such an approach would cause to a unique environment would be to great. Instead, tidal stream generators are being considered for the area. One of the benefits of such a system would be that at low tide the turbine would be exposed, leaving hours each day for maintenance and repair. Of course, this also means the system won’t be generating power for that length either. Estimates suggest that tidal installations in various regions of New Brunswick could total nearly 3.9 TWh by 2035.
On the west coast of Canada, the approach to tidal power generation has taken a different trajectory. Because the area experiences lower tidal rises, but stronger tidal currents, a tidal stream generation scheme has been installed. The first system was put into place in 2006 in Race Rocks, which is near Victoria. The system is unique in that it is the first of its type in North America. Initially it was intended to be water lubricated and to generate 65 kilowatts using a bidirectional generator. However, the saltwater proved to be too much for the bearings and the system was decommissioned in 2007 so that it could be redesigned.