Numerical study to estimate the wave energy under Wave-Current Interaction in the Qingdao coast, China

The purpose of this study is to characterize how the Wave-Current Interaction (WCI) at a specific location modifies the wave energy available for conversion. In this work, a third generation spectral model MIKE21 SW (version 2014) is utilized to investigate the wave energy resources under WCI in the Qingdao coast. This model can directly calculate the wave power in terms of the wave spectrum, which improves the accuracy of the wave energy estimation, especially in the nearshore zones. Here, the models run for coupled (waves and currents) and uncoupled (only waves) modes over the whole year of 2014 with the same model setup, except the tide currents setting. The results indicate that the annual mean differences between coupled and uncoupled models are mainly occurred in the nearshore zones, varying up to 100% when the WCI effect is neglected. Further investigations reveal that those differences can be attributed to the tidal level, the strength of currents and the relative wave direction, which may cause underestimation or overestimation of the wave energy resources. This work confirmed that the WCI should be considered when performing estimation of the wave energy resources in the shallow nearshore zones with macro tidal range and current.