Offshore wind power generation has significant advantages, including enhanced energy security and job creation. However, despite these benefits, South Korea has not fully utilized its potential in this sector. In contrast, offshore wind power industry development in Europe has been driven by government leadership. Drawing from this experience, South Korea also needs to relax regulations, strengthen necessary infrastructure, and enhance financial support systems to activate the offshore wind power industry. For this, sustained government leadership is absolutely essential. Without addressing the capacity issues in the power grid, we cannot expect offshore wind power generation to succeed. To address grid issues, we propose the enactment of a special law called the "Special Act on Grid Expansion." Considering KEPCO's financial situation, private investment should be encouraged for grid construction. The role of developers is crucial for the successful development and operation of offshore wind power. They manage risks throughout various stages, from site acquisition to construction and operation, which have a significant impact on the success or failure of projects. Since domestic developers currently lack experience in offshore wind power, a cooperative strategy that leverages the experience and technology of advanced countries is necessary. Energy issues should be recognized as important tasks beyond mere political ideologies, as they are crucial for the survival of the nation and its development. It is essential to form a public consensus and implement ways for residents to coexist with offshore wind power, along with the conservation of marine ecosystems and effective communication with stakeholders. Expansion of the offshore wind power industry requires support in various areas, including financial and tax incentives, technology research investment, and workforce development. In particular, achieving carbon neutrality by 2050 necessitates the activation of offshore wind power alongside efforts by major corporations to transition to renewable energy. South Korea, surrounded by the sea, holds significant offshore wind power potential, and it is our responsibility to harness it as a sustainable energy source for future generations. To activate the offshore wind power market, we need to provide financial and tax support, develop infrastructure and research, and foster a skilled workforce. As major corporations transition to renewable energy to achieve carbon neutrality by 2050, offshore wind power must play a significant role. It is our responsibility to fully utilize South Korea's potential and make offshore wind power a new driver of growth.

As the generation capacity of floating offshore wind turbines increases, the wind load applied to each turbine increases. Due to such a high wind load, the capacity of transport equipment (such as tugboats or cranes) required in the transportation and installation phases must be much larger than that of previous small-capacity wind power generation systems. However, for such an important wind load prediction method, the simple formula proposed by the classification society is generally used, and prediction through wind tunnel tests or Computational Fluid Dynamics (CFD) is rarely used, especially for a concept or initial design stages. In this study, the wind load of a 10 MW class floating offshore wind turbine was predicted by a simplified formula and compared with results of wind tunnel tests. In addition, the wind load coefficients at each stage of fabrication, transportation, and installation are presented so that it can be used during a concept or initial design stages for similar floating offshore wind turbines.

In order to respond to environmental changes and various events in the nearby sea area due to the operation of an offshore wind substantiation farm in the Southwest Sea, X-band radar has been installed and operated on a fixed platform since 2018. The X-band radar's monitoring system produces wave and current data through Rutter's Ocean WaveS wave and current (Sigma S6 WaMoS II). In this study, to verify the reliability of the produced data, the accuracy of current and wave data was evaluated by analyzing the correlation with the results obtained by an acoustic doppler current profiler (ADCP). The selected analysis period was a total of 30 days from November 29 to December 28, 2021, the period during which the ADCP survey was conducted. As a result of comparative verification, the current, wave height and peak wave period (H_s > 0.69 m) data observed from the X-band radar showed a high correlation with the results investigated from ADCP. In the future, current and wave data produced by X-band radar are expected to be used as basic data to analyze environmental changes in sea areas and provide information on various events.

This paper examines the design feasibility of cage aquaculture coexistent with an offshore wind farm in the southwestern sea of South Korea. Among the many types of fish farms, 2 × 3 cage aquaculture was selected for the investigation and the initial design including mooring lines, bridles, etc. was drawn with iterative numerical simulations using Orcaflex. Experimental campaigns were conducted to validate the numerical results, and they were found to be in good agreement with the experiments. Using a validated numerical model, the tension of mooring lines and the deformed volumes of the facility were examined under given operating and survival conditions. The validated model will be further used to investigate various aspects of the cage farm design for design optimization.

This study performed a response analysis according to the transmission error of the yaw drive. To perform the response analysis, the excitation source of the transmission error was modeled and the outer ring of the first stage bearing and the outer ring of the output shaft bearing were used as measurement positions. The response results were analyzed based on the vibration tolerance values of AGMA 6000-B96. As a result of the response of the first stage bearing outer ring, the maximum displacement of the first stage planetary gear system was 5.59 and the maximum displacement of the second to fourth stage planetary gear systems was 4.21 ㎛ , 3.13 ㎛ , and 25.6 ㎛ . In the case of the output shaft bearing outer ring, the maximum displacement of the first stage planetary gear system was 1.73 ㎛, and the maximum displacement of the second to fourth stage planetary gear system was 1.94 ㎛, 0.73 ㎛, and 2.03 ㎛. According to AGMA 6000-B96, the vibration tolerance of first stage is 17.5 ㎛, and the vibration tolerance of the second to fourth stages is 58 ㎛, 80 ㎛, and 375 ㎛, which shows that the vibration tolerance is satisfied and it is safe.

Floating LiDAR systems provide significant savings in cost and time compared to the fixed meteorological mast measurement type, and have the advantage of being able to be deployed in various locations due to less restriction on the depth of the installation site. However, to use the wind data collected by a floating LiDAR system commercially, verification procedure is required to ensure that the collected data have sufficient availability. The Carbon Trust OWA roadmap presents guidelines in three stages for the reliability of the wind data collected using a floating LiDAR system. Companies developing wind farms are requesting at least Stage 2 (pre-commercial stage) presented by OWA, and many overseas companies are leading the domestic and overseas markets. In this paper, we introduce the case of OWA Stage 2 certification for the commercial operation of floating LiDAR systems.

In this study, a hardware-in-the-loop simulation (HILS) environment was established using MATLAB/Simulink to simulate and verify the power performance of a wind turbine. The target wind turbine was selected as the NREL 5 MW model, and modeling was performed based on the disclosed specifications. The HILS environment consists of a PC equipped with a MATLAB/Simulink program, a programmable logic controller (PLC) for uploading and linking control algorithms, and data acquisition (DAQ) equipment to manage wind turbine data input and output. The operation of the HILS environment was carried out as a procedure of operation (PC) of the target wind turbine modeled based on MATLAB/Simulink, data acquisition (PLC) of control algorithms, control command calculation (PLC), and control command input (PC). The simulation was performed using the HILS environment under turbulent wind conditions and compared with the simulation results performed under the same conditions in the HILS environment using the commercial program Bladed for performance verification. From the comparison, it was found that the dynamic simulation results of the Bladed HILS and the MATLAB HILS were close in power performances and the errors in the average values of rotor rotation speed and power generation between the two simulations were about 0.44 % and 3.3 %, respectively.

In order to understand water depth distribution in the waters of the southwestern sea offshore wind power demonstration complex, field observations were conducted using a multi-beam echosounder from before construction (2018.2) to operation (2022.8). After data processing and correction of the observed depth, cross-sectional analysis was performed to calculate the maximum water depth value, and time phase analysis was performed using the maximum water depth value. The maximum water depth change rate over time tended to gradually decrease, and there was little difference in the rate of change before the construction of the wind turbine foundation structure, and the rate of change was rapid when the foundation structure was under construction. As a result of time phase analysis, the rate of change of the first (2018.02) and the second (2018.05) showed a rate between -6.27 and -4.13, on average, as the rate of change before the construction of the offshore wind farm, and there was no difference between the first and second rates. The third (2018.11) rate of change was -4.25 to -1.82, and the fourth (2019.04) rate of change was -2.34 to -1.22, and the rate of change increased rapidly after the third time. The fifth (2019.07) rate of change was -2.11 to -1.31, the sixth (2021.05) rate of change was -2.09 to -1.28, and the seventh (2022.08) was -2.11 to -1.22 rate of change, and after the rate of change reached some extent, the change was analyzed in an insufficient graph.

Bio-fouling has positive aspects that are used as a fish resource, but there are also negative aspects such as corrosion of the surface of the support structure, aesthetics and work safety problems. A specimen was produced using a polyurea material with excellent anti-fouling and methodology, and contact angle, high water pressure, adhesion, and real sea area tests were performed. As a result of measuring the contact angle of the specimen with a 10 cm x 10 cm area of polyurea, There was found to be an average of 124.4 ° at nine points. No surface damage was found even above 5 Mpa when high water pressure was sprayed, and adhesive strength of 300LSE adhesives was confirmed between 22.84 and 23.04 Mpa with an adhesion test. During the 6-month real sea area test, it was confirmed that about 17.24 % of the polyurea film was less generated than the comparison group.

Rapid progress is being made in foundational technology research and engineering for the construction of floating offshore wind farms. There is active development of technology for detachable mooring systems, which have strengths in addressing maintenance issues that arise in floating offshore wind farms and enhance their economic viability. Conventional detachable mooring systems use Kenter links inserted into the middle of mooring chains, which require excessive time for retrieval by Anchor Handling Tug Supply (AHTS) vessels during detachment operations. Moreover, these operations pose risks of link damage and accidents. Therefore, there is a demand for the development of a new concept of detachable mooring systems. The proposed detachable mooring system in this study simultaneously integrates a fairlead chain stoppers (FCS) and submersible mooring pulleys (SMP), which enables all operations to be conducted on the AHTS vessel without underwater tasks. This study detailed the design and safety evaluation of the SMP, a core component of the detachable mooring system, based on the minimum breaking load (MBL) of selected mooring lines according to the capacity of the floating platform. It referenced international codes (AISC Specification for Structural Steel Buildings D5, Pin-Connected Members) for design verification and performed finite element analysis to evaluate the strength of major components in installation and operation scenarios. Additionally, procedures and techniques for evaluating the structural strength of components under uncertain boundary conditions were proposed.