The estimates of global potential of tidal energy generation vary, but it is widely agreed that tidal stream energy capacity could exceed 120 GW globally.
It has been estimated that tidal stream energy could theoretically supply more than 150 TW/h per annum, well in excess of all domestic electricity consumption in the UK. This represents a potential total global market size of up to 90 GW of generating capacity.
The UK’s tidal power resource is estimated to be more than 10 GW, representing about 50 percent of Europe’s tidal energy capacity.
25 percent of Europe’s tidal energy potential resources come from Scotland.
The Pentland Firth, widely considered to be one of the world’s best sites for tidal power, could provide half of Scotland’s electricity, according to study recently completed by Oxford University. “It is almost certainly the best site for tidal stream power in the world,” said Thomas Adcock, from Oxford University. The water flow is rapid there because the tide shifting from the Atlantic into the North Sea is forced through a narrow eight-mile channel.
The Oxford University engineers calculated that underwater turbines strung across the entire width of the Firth could generate a maximum 1.9 GW of power, averaged across the fortnightly tidal cycle. That is equivalent to 16.5 TW/h of electricity a year, almost half Scotland’s entire annual electricity consumption in 2011. As Scotland already produces 14.6 TW/h a year of renewable energy, a fully exploited Pentland Firth would bring Scotland close to meeting its aim of 100% renewable electricity by 2020.
The Bay of Fundy between New Brunswick and Nova Scotia is the most promising location in Canada for tidal energy and could potentially produce as much as 30.000 MW of energy .
China has abundant resources of tidal power with more than 18.000 kilometers of mainland coastline and more than 14.000 kilometers of island coastline, with an estimated tidal power capacity of 3.5 GW according to the China Ocean Energy Resources Division.
Australia and New Zealand have large ocean energy resources but do not yet generate any power from them.
Other territories with significant tidal power potential include North America, Argentina, Russia, France, India and South Korea.
