I always had so many questions swirling (sorry for the bad puns) around in my head about Tidal power and its inner workings, but never really looked it up. This video, minus the tacky music, does most of that, including my questions on the impact of the blades on marine ecosystems and species ( although I am not too sure this has been fully tested and the 'bat & bird' critics may change to 'shark & dolphin' outcries ... Depends on how much the lobbyists pay!)
Translated, a five-knot ocean current carries more kinetic energy than a 220 mile-per-hour wind and, in a boon to the economics of such projects, tidal turbines can be physically smaller than their above-ground cousins. The blades of tidal turbines move slower than above-ground turbines, which reportedly make them less likely to damage below-surface ecosystems.