Long-term variability analysis of wave energy resources and its impact on wave energy converters along the Chinese coastline

The long-term variability of wave energy resources will affect the practical decadal application of wave energy converters. This paper has evaluated the distributions and long-term trend of wave energy resources in the sea regions along the Chinese coastline for 83 years based on reliable ERA5 wave reanalysis data from 1940 to 2022 after verifying by 39 local buoys, and found that it is of great potential to develop and apply wave energy resources projects. The long-term trend analysis of the wave energy density and its major contributing wave parameters, significant wave height, and wave energy period, is carried out using Theil-Sen estimation showing the general positive tendency. And the impacts of the decadal variation on four wave energy converters are evaluated via computing the decadal mean power production by combining the wave energy density and the wave energy characteristic. It is verified that the long-term wave energy density in this region increases along with the decrease in power production and the capture width. This study shows that long-term variability of wave energy resources and wave energy characteristics should also be considered in the designing of WECs and the identification of energy hotspots.