Assessment of wave energy resources and their associated uncertainties for two coastal areas in Japan

At reconnaissance to feasibility study stages of wave energy development, guidelines and standards recommend wave power assessments to be conducted for long periods of time, albeit at relatively coarse spatial resolutions. However, quite often developers need to make a preliminary site selection based on high-resolution information. Unfortunately, even with abundant computational resources nowadays, running a high-resolution coastal model for more than a decade is still not practical. In this paper, we propose to combine uncertainty estimates from a 21-year-long 1-km-resolution model and a high-resolution (10 m nearshore) coastal model to assess wave energy. Two sites in Japan facing the Pacific Ocean were selected for this study. One site located on the southern coast (site-S) is affected more by the passage of typhoons than another site located on the eastern coast (site-E). The estimated wave power climatology at site-S ranges between 3 and 7 $$\text{kW}\,\text{m}^{-1}$$ with an uncertainty of ± 0.27 to ± 0.51 $$\text{kW}\,\text{m}^{-1}$$ ; whereas for site-E, the climatology varies between 3 and 9 $$\text{kW}\,\text{m}^{-1}$$ with uncertainties of ± 0.12 to ± 0.34 $$\text{kW}\,\text{m}^{-1}$$ . In general, the eastern coastal area of Japan is found to offer higher wave power and lower margins of uncertainty than compared with the southern coastal area.