Current from Tidal Current

8.1 Introduction

With at least sixty major papers in print and several international conferences on the subject, over the last decade, it appears that, contrary to assertions made in some trade-and-news journals, interest in tidal power—using barrages—is far from being on the wane.1,2 This is particularly true in the Far East, viz. China, Japan, Korea.3

Tidal power can be harnessed, as did tide mills, by creating a retaining basin and using the up and down movement created by the tides, or by diverting part of a flow and using the to and fro movement of the tide induced current, pretty much like a run-of-the-river approach.4 The flow of the tidal current is diverted in part into a channel where it turns a wheel: some tide mills operated by tapping the energy of the tidal current.5 Substitute a turbine, place it in the dam and you have a tidal current energy plant.

In discussions dealing with extraction of tidal energy, tidal current power has been far less often mentioned that tidal barrages yet, this “sleeper” has been [195] [196] considered as a power source with steadily increased frequency for better than a decade.6,7,8,9 As one may dispense with cofferdams, barrage, sluices and retaining basin, a tidal current power plant can be built and provide electricity far less expen­sively. Electricity production is of course more modest than with a “barrage plant”. The view that tidal currents constitute a big saving compared to barrage schemes is not, however, held universally.[197] [198] [199] [200] [201] [202]

An advantage of the tidal current resource is that being gravitational bound, it is highly predictable; it is, however, not in phase with the solar day. One hundred six locations in Europe if put “in service would provide 48 TWh/yr exploitable.11

Updated: September 23, 2015 — 6:33 pm