Tidal energy site characterisation in a large tidal channel in Banks Strait, Tasmania, Australia

Abstract

Banks Strait is a 15 km wide tidal channel in Tasmania, Australia, and has been identified as a prospective site for tidal energy extraction, however flow characteristics have never been investigated. We present detailed field measurements from campaigns which deployed multiple Acoustic Doppler Current Profiles (ADCPs) across Banks Strait to analyze energy resources. The deployment period lasted for almost a year including a rigorous technical assessment of tidal stream resource that exceeded IEC site characterisation standards. Our results reveal that the Banks Strait channel has sufficient depth but that tidal currents generally do not exceed 2.5 m/s at the mooring sites. Large areas reveal an active wave climate and significant wave current-interaction. Maximum values of in-situ tidal kinetic power densities were approximately 0.85 kW/m2 on the southern side of the channel. The northern side suggests even more energy potential although ADCPs could not be recovered due to strong currents and sediment movement. The results will feed into numerical models to further investigate the energy potential. Based on our in-situ estimates, a tidal turbine farm could bring significant advantages to the region by reducing intermittency and increasing constant energy extraction to support an already existing wind farm located in north eastern Tasmania.