Canada: Tidal power plants and other turbine systems harness the moving water to create renewable energy

Tidal current energy

Tidal energy is produced by the rise and fall of tides from the gravitational influence of the sun and moon. It can take two forms: tidal current and tidal range. Currently, Canada is not pursuing energy extraction from tidal range due to high capital costs and environmental concerns. 
 
However, Canada is pursuing tidal current energy extractions. Tidal currents are reliable and predictable, offering great potential to power turbines and generate electricity. Some 190 tidal power sites have been identified off Canada’s coasts with a total estimated capacity of 42,000 MW (total mean annual wave power)—more than 63 percent of the country’s annual total consumption. Nunavut has the country’s greatest abundance of tidal resources; British Columbia has the most sites with potential power greater than 1 MW.

Not all of this potential energy can be converted into usable power without noticeable impact on tides and tidal flows. However, tidal energy is scalable: it can start with one turbine and over time scale up to multiple turbines. Tidal current energy is a renewable, zero-emission option with high power density.

Wave energy

Wave energy is a concentrated form of solar energy: ocean waves form as a result of the sun heating the ocean surface. The motion of the waves can be used to power turbines or other power take-off systems to generate electricity.

The waters off Canada’s Pacific and Atlantic coasts are rich with wave energy resources. Roughly 37,000 MW of total mean annual wave power off Canada’s Pacific coast—equal to more than 55 percent of the country’s annual electricity consumption. The potential capacity off Canada’s Atlantic coast is even greater: about 146,500 MW, or more than double current electricity demand. As with tidal energy, not all of these available wave energy resources can be realized as usable power due to various factors including socio-economics, the harsh ocean environment, power conversion losses, and cost.

River current energy

Energy can be drawn from free-flowing river currents much as it can from the tides. Some developers have been able to deploy similar technologies in both tidal and in-stream river current environments. The resource potential in Canadian rivers is still unknown. A three-phase project is underway to establish preliminary estimates.