Primitive tidal mills operated in the England date back to the 11th century. During the 18th century, several tidal mills popped up in Western Europe. The news that the world's largest tidal turbine â€“ 1 MW in size â€“ will be installed off the coast of Scotland near Orkney should come as no surprise.
Scotland is the hot spot for tidal power in all of northern Europe, with the Pentland Firth often described as the "Saudi Arabia of tidal power." The U.K. and Ireland also feature among the best tidal sites in the world, because they are relatively close to people. Some from these islands near the European coast may argue with this assessment, but when compared to the U.S. â€” where 95% of the nation's tidal resources rise and fall off the coast of remote Alaska â€” it becomes clear it is all a matter of perspective.
Tidal stream turbines often look suspiciously like wind turbines placed underwater. Tidal projects comprise over 90 percent of today's marine kinetic capacity totals, but the vast majority of this installed capacity relies upon first generation "barrage" systems still relying upon storage dams (see forecast below.)
Pike Research will be issuing a revised forecast of ocean energy technologies next year, with lower capacity totals given the lack of progress on carbon regulations and the lingering recession, but this 2009 forecast shows how tidal systems dominate the near-term market for ocean energy technologies.
The basic selling points for tidal as follows:
-Tidal resources have the highest power density of any of the marine renewable technologies, hence the lowest cost estimates.
- Unlike many renewable resources including solar and wind power, tidal resources can be accurately predicted literally years in advance.
- Tidal devices are typically sited below the ocean surface: they canâ€™t be seen; canâ€™t be heard; and, in most instances, would not interfere with shipping or other maritime uses.