Wind speed interannual variability with measured data validations and its impact on energy yield in the Southwest Sea of Korea

The Republic of Korea (ROK) has set an ambitious goal of 40.7 GW of onshore and offshore wind farms by 2038, as outlined in the "11th Basic Plan for Electricity Supply and Demand" in May 2024. To achieve this target, both wind farm developers and the government are crafting policies for "Project Site Planning" and "Offshore Wind Farm Clusters". A major concern for stakeholders is the variability in annual wind resources driven by climate phenomena and climate change, which can lead to increased uncertainty in energy yield predictions. This study investigated the interannual variability (IAV) of wind speed in the Southwest Sea of Korea, a critical factor influencing energy yield predictions and the levelized cost of energy (LCOE) for offshore wind farms. To achieve this goal, we used reanalysis datasets validated against measurement data to calculate a ROK-specific IAV. Our findings indicate the possibility of reducing LCOE estimation by accurately accounting for regional IAV, particularly in Jeonnam, where 14 GW of offshore wind capacity is projected. This research provides essential data for improving energy yield predictions, thereby enhancing financial confidence and supporting the development of expertise in the growing wind energy sector in the ROK.