Abstract
As the deployment scale of wave farms increases towards hundreds of MW installed capacity, it becomes important to understand how nearshore coastal processes may be modified by energy extraction. Most of the published studies on the environmental impact of wave energy converters represent a group of devices using transmission and absorption coefficients. This approach represents the average energy extraction across the power spectrum but, since wave device performance is dependent on the wave frequency, the use of frequency-dependent transmission coefficients may be more appropriate. In this study, SWAN is used to investigate how the definition of a frequency-dependent transmission coefficient, based on an idealised point absorber, alters nearshore conditions relative to a constant transmission coefficient. Experimental measurements are also presented to quantify the change of wave characteristics due to a small array of heaving point absorbers. Wave spectra measured down-wave and up-wave of arrays comprising five- and ten-devices are compared to those measured at the same location prior to device deployment. The influence of these modifications on breaking conditions near the shoreline is briefly discussed and the measurements provide the basis for evaluation of numerical models of device arrays at the site scale.