Interaction of ocean wave energy converters

Abstract

It is expected that several identical Point Absorber Wave Energy Converters (PAWECs) will be arranged in arrays to form a Wave Energy Farm. One of the key challenges in designing such a WEC array is their spatial configuration, as the WECs in the farm interact hydrodynamically with each other. This study focuses on different potential PAWEC deployments to identify the best relative position in order to maximise energy output. This is done by resolving the hydrodynamic interactions between a modelled WEC point absorber, with use of open-source Boundary Element Methods (BEM) and time domain WEC simulator. The results from the numerical model are also compared with wave tank testing, to verify
the accuracy of the analysis. The simulations show that the relative position can significantly increase a WEC’s individual power output. A spatial pattern of relative positions that result in higher potential power extraction was shown, with increases up to 20% compared to a single WEC on its own. However, the computational results showed realistic results for only a select number of configurations. As for the experiment, unexpected variations in test conditions occurred, inhibiting the possibility to isolate certain events. Therefore, when cross checking results from both simulations and experiments, the identified simulated trends only partially showed adherence with the experimental data. Henceforth, the knowledge gathered from the simulations can’t conclusively be validated by the experiments conducted in this study. This study shows that the spatial configuration of two WECs influences their individual power outputs.