Ocean energy is produced in various forms (e.g., from tidal currents, wave energy, ocean thermal energy and salt gradient energy). Ocean energy technology is relatively new and only tidal current energy (tidal energy) technology has been applied on commercial scales. There is worldwide interest in tidal energy because tidal energy resources are up to 50 times as dense as wind resources and are 100 times more efficient than solar photovoltaic (PV) resources. The advantage of using tidal currents to produce electricity is their predictability and persistence. Presently, there are two leading ways to convert tidal energy into electrical energy: tidal barrages and in-stream turbines. Tidal barrages are similar in concept to hydroelectric dams, where water is stored and directed through turbines to generate electricity. In-stream tidal turbines are analogous to wind turbines in that turbines are designed to utilize existing current flows without necessarily controlling them.
There are a number of different in-stream tidal turbine designs, but all follow the same principle of using the ebb and flow of underwater tides to rotate a turbine. In-stream turbines are submerged and are usually installed onto the seafloor. In-stream turbine technology is currently being investigated in Canada (e.g., British Columbia and Nova Scotia), the United States (e.g., Alaska), and Europe (e.g., Ireland and Scotland).
The cumulative mean potential tidal current energy of Nunavut is estimated to be highest in Canada. Many sites with tidal energy potential are in remote parts of Nunavut and it may not be feasible to explore the development of tidal energy in these areas. In-stream turbines are expensive and investing in the development of tidal energy may be risky especially when considering Arctic conditions and issues. There is potential for tidal energy development in Frobisher Bay, where tides are among the highest in Canada. In-stream turbines in Frobisher Bay could supply electricity for Iqaluit, where population numbers and electricity demand may be at high enough levels to support the high cost of tidal energy development.
Modeling studies of tidal currents and tidal energy in Frobisher Bay are recommended as next steps in assessing tidal energy potential for Iqaluit. Sea ice conditions in the bay have to be considered as well as sea ice and sea ice floes could negatively impact the turbines.