Meteo-Climatic Conditions of Wind and Wave in the Perspective of Joint Energy Exploitation: Case Study of Dongluo Island, Hainan

Combined wind and wave power generation has advantages such as energy synergy and complementarity and will play a leading role in the integrated development of offshore renewable energy. From the perspective of joint energy development, this study focuses on the meteo-climatic wind and wave conditions in Dongluo Island, Hainan, in the South China Sea. Based on the concurrent measurement from in situ monitoring system, hourly data from June 2020 to September 2021 are used to reveal typical climate characteristics associated with the weak (inverse) correlation between wind and wave. The energy flux density of wind and wave are also assessed to describe the energy pattern. Principal component analysis (PCA) shows the wind parameters contribute a larger variance to the matrix of the wind-wave dataset than the waves, suggesting a lower stability of the wind climate. The first three components via PCA are then classified into five clusters to represent different climatic characteristics. Among them, the dominating cluster symbolizes a climatic circumstance with weaker winds and waves below normal. This cluster, evenly distributed in different seasons, shows the lowest wave-wind correlation, suggesting a favorable condition of the synergy of the two energies throughout the year. The clusters with the second and third largest sample sizes are mainly dominated in spring and winter, respectively. The magnitudes of the wind and wave parameters in these two clusters yield to a relation of "as one falls, another rises", implying a high interest in complementarity between the two resources to a certain extent. The energy features inferred by meteo-climatic clusters are further verified by direct assessment of energy density. There are generally consistent variations between wind-wave climate and energy, both in magnitude and in seasonality. Based on these results, differentiated exploitation schemes considering the complementarity or synergy of wind and wave according to different seasons are recommended.