Physical Modelling Of The Wave Field Around An Array Of Centrally Controlled Wave Energy Converters

Abstract

To capture a substantial amount of wave energy, Wave Energy Converters (WECs) will be placed in arrays in a certain geometric configuration.  WECs spaced closely together will interact, affecting the hydrodynamics of these devices and thus the total power absorption of the WEC array. These are called ‘near-field effects’. Furthermore, a WEC array will also influence the wave field in the wake zone behind the farm, the so-called ‘far-field effects’. This affects the coastline and other users of the sea near the WEC array. Both near- and far-field effects are caused by the modification of the incident waves due to wave radiation by and wave diffraction around the WECs. To understand these effects, it is therefore necessary to study the wave field in and around a WEC array. This study investigates the wave field modifications for an array of up to five heaving point absorber WECs that was tested at the Coastal & Ocean Basin Ostend. To optimize the absorbed power of the array, the Power Take-Off (PTO) devices are controlled using a centralized control algorithm, influencing the hydrodynamic behaviour of the WECs and hence the wave field. The research fits into the larger scope of the ‘WECfarm’ project, which has been initiated to address the lack of available realistic and reliable data covering large centrally controlled WEC arrays to validate numerical models (Vervaet et al., 2022).