Tidal Power

Tidal power can use either conventional or new technology to extract energy from a tidal stream.  It is usually deployed in areas where there is a high tidal range.  Typically a barrage, or what might be described as a wall dam, with turbines is built across an estuary or a bay.  As the tide rises it creates a height differential between the inner and outer walls of the barrage.  Water can then flow through the turbines and drive generators.  Some tidal barrages operate on both the rising and the falling tide, but others, particularly estuarine barrages, are designed to operate purely on the falling side.

It is also possible to make use of the tidal flow that occurs between headlands and islands or in and out of estuaries.  It is this application that is the focus of much research and development, and new products for this purpose are now being commercialized.  These "in-flow" tidal turbines can be arranged singly or in arrays allowing a range of power outputs to be produced.