Preliminary Estimation of Tidal Current Energy for Three Straits in the Vicinity of Bali and Lombok Islands

Abstract

Indonesia is an archipelago country which has a great potential of ocean energy resources including tidal current and wave power. In this present work, tidal power in three different straits, namely Alas strait, Bali strait and Lombok strait will be estimated. In order to achieve our goal, a two-dimensional, depth-integrated Advanced Circulation (ADCIRC-2DDI) model was employed. Eight tidal constituents were imposed along the ocean open boundaries. Two different sources of tidal constituents namely Le Provost and OTIS (OSU Tidal Inversion Software) were used. Tidal elevations have been validated and calibrated against tide gauge data in which at least six tide gauges are available in the study location. We found that, tidal constituents from high resolution database that is OTIS give better results. Open boundary conditions have been improved using Green’s function approach. As a result, significant reduction of the root-mean-square error (RMSE) has been obtained. This indicates that the method is powerful.  Furthermore, tidal current energy was estimated. Since there is no tidal current observation available in the area, tidal velocities were compared with the tidal current obtained from finite element solutions 2014 (FES2014). We found that tidal current obtained from ADCIRC model has a very good agreement with FES2014. Moreover, tidal current speed in the vicinity of Bali and Lombok islands could reach up to 3.8 m/s. As a consequence, tidal current power could exceed 10.98 kW / m 2 with assuming that turbine efficiency is about 0.39.