3.3.3. Potential
It is estimated that the United Kingdom could generate up to 50.2 TW h/yr with tidal power plants, while western Europe as a whole could generate up to 105.4 TW h/yr. Total worldwide potential is estimated to be about 500–1000 TW h/yr, though only a fraction of this energy is likely to be exploited due to economic constraints [30]. The availability of tidal energy is very site specific, where tidal range is amplified by factors such as shelving of the sea bottom and funneling in estuaries, reflections by large peninsulas, and resonance effects when tidal wave length is about 4 times the estuary length, as in the bay of Fundy [34]. Major potential sites for barrages include the Bay of Fundy in Canada, which with a mean tidal range of 11 m has the highest tides in the world, and the Severn Estuary off Britain [30]. Tidal fences and turbines could be installed anywhere tidal flows and the constraints of topography create predictable currents of 2 m/s or greater.