Tidal energy: a promising future resource for Tasmania

Batman Bridge (Tamar Estuary) and Swan Island (Banks Strait) in Northern Tasmania, Australia have previously been identified as potential tidal energy extraction locations [1]. Measurements with a bottom-mounted acoustic Doppler current profiler (ADCP) over two tidal cycles at each location were analysed to estimate the energy potential. The Batman Bridge data showed good symmetry between flood and ebb tides, both achieving maximum velocities over 2.4 m/s at approximately 180° out of phase. These characteristics allow the Batman Bridge site to meet average energy demand for 180 Tasmanian homes. This site also exhibits characteristics equivalent to those at existing tidal sites such as Paimpol-Bréhat, and from this, offers an exciting resource for Tasmania to harness.

The Swan Island site characterisation revealed a mean velocity of 0.81 m/s occurring during flood tide which is approximately 25% stronger than the ebb tide with 0.64 m/s. A maximum velocity of 1.79 m/s was recorded, yet, the mean power density only reached 0.2 kW/m². This region does not exhibit energetic enough characteristics, however comparisons to works completed show great potential for the greater Banks Strait region to be further investigated.