While Nova Scotia’s Minas Passage is one of the most promising industrial-scale tidal-electricity resources in the world, several marine engineering issues, the most obvious of which are related to the seasonal presence of ice, need to be resolved before this renewable energy resource can be accessed year-round.
Prior to the installation of the hundreds of modular tidal electricity harvesting devices planned for this roughly 8 km by 16 km area, engineering strategies need to be developed to:
• avoid, minimize or tolerate occasional contact between tidal current harvesting devices and seasonal surface ice and sub-surface masses such as sediment-laden ice cakes, water-logged trees and large marine vertebrates; and
• avoid, minimize or tolerate damage to tidal current harvesting devices and their associated cables from seafloor turbulence such as reciprocating tidal-current-driven sea-bed sediment storms mobilizing mud, silt, sand, cobbles and/or boulders.
Obvious prerequisites to the development of engineering strategies for these two issues are studies to quantify the risk of both sub-surface collision and seafloor turbulence. Specifically required are:
• an annual sub-surface census of all macroscopic traffic through the Minas Passage; and
• a year-long monitoring of sea floor dynamics at all sites where tidal devices and their associated cables are to be located.