Tidal Stream Energy Resource Assessment of the Shannon Estuary, Ireland

The Shannon River and its estuary is one of the largest such systems in the British Isles. The tidal range at the mouth and head of the estuary is over 5m and 6.5m, respectively, during normal spring tides, inducing peak... [ view full abstract ]

The Shannon River and its estuary is one of the largest such systems in the British Isles. The tidal range at the mouth and head of the estuary is over 5m and 6.5m, respectively, during normal spring tides, inducing peak currents of up to 3m/s in water depths of 35m. The estuary has rightly been identified as a potential location for tidal energy extraction; however, little detailed analysis has been carried out to accurately determine its tidal energy potential.
The primary aim of this research is to accurately quantify the potential tidal stream resource available in the estuary. A weakness of traditional resource assessment studies is that they ignore the directionality of tidal flows. This research utilises tidal current ellipses to incorporate the prevailing direction of flow into available power calculations, resulting in a more accurate assessment. A secondary aim is to carry out a more detailed resource assessment at particular sites that have been designated as tidal energy berths.
It is shown that the available power resource can vary substantially depending on the assessment methodology that is employed and that omitting the effects of flow direction from an assessment leads to significant overestimation of the available resource.