Wave data analysis for a semi-sheltered site in the Inner Hebrides of Scotland suitable for small scale WEC development

Abstract

Wave data analysis from a short-term deployment of a wave buoy and AWAC in the lee of a Hebridean island in the United Kingdom is discussed in this paper. Significant parameters are calculated and Rayleigh, Weibull and Kernel density probability distributions have been employed to fit the measured data. Results show that while the Atlantic facing side of the island is exposed to a predominant swell based wave regime, the area in the lee features bimodality for wave period and directionality. The Kernel density distribution is found to fit the measured bimodality well compared to Rayleigh and Weibull distributions. The analysis illustrates that interference between swell waves and associated wave periods from north with southerly wind driven seas creates a complex sea state. It is shown that the higher wind sea related frequency components are of more significance in the lee of the island than at the open ocean site. Findings of this study are relevant to the aquaculture sector or small scale wave energy developers (e.g. <100kW), as an insight is provided into the interaction between ocean swell and localised wind seas in semi-sheltered areas.