• Journal of Wind Energy
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• v.14 no.2
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• pp.14-25
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• 2023

This study focuses on proposing measures for the reasonable development of offshore wind farms using the case of Norway, which was the first nation in the world to build a floating offshore wind farm of 80 MW or more. Norwegian authorities conducted a strategic environment assessment in 2012 to select offshore wind farm sites, discovered 15 potential sites, and finally decided on two designated sites in 2020. Based on various survey data such as seabirds, marine environment, and fishing activities, scientific-based spatial analysis was conducted to select additional offshore wind farm sites in line with future development plans. In addition, a government-led steering committee and advisory group have established marine spatial plans since 2002. Therefore, it will be possible to listen to and coordinate the opinions of stakeholders by using the steering committee and advisory group for offshore wind power development. By examining the case of Norway, we suggest the following policy points that can achieve carbon neutrality and develop sustainable offshore wind farms: 1. Establish a government-led steering committee and advisory group that can select potential sites for offshore wind farms by coordinating the opinions of stakeholders 2. Induce efficient and sequential offshore wind farm development by using various survey data and scientific-based spatial analysis.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.33 no.5
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• pp.179-186
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• 2021

We need measures that can come up with alternative about fishery living zone and enhance local acceptance for responding to the increase in the proportion of renewable energy production and construction of 12GW Offshore wind power according to Korea's Renewable Energy 3020 initiative and Korean-version New Deal. In this study, We suggest that differentiation plans of co-location model in connection with offshore wind power generation suitable for the East Sea. The East Sea is an optimal site for building of a floating offshore wind power generation(FOWPG) field. It is expected that economic effects like energy production, aquatic resource development and tourism industrialization by farming bluefin tuna which is high valued fish and suitable for offshore aquaculture on public waters in FOWPG field. And we can confirm that budget reduction, smart management by sharing operation management technology and increase in fishermen income.

• Journal of Wind Energy
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• v.13 no.1
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• pp.5-14
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• 2022

Currently, the Korean government is driving the construction of large-scale floating offshore wind farms to increase domestic renewable energy generation and decrease carbon emissions. In offshore wind farms, maintenance approaches can be limited more often than onshore wind farms by marine weather conditions (wave height, etc.). Therefore, maintenance planning optimization is more important to minimize maintenance costs and power generation loss by downtime. Additionally, the power generation of a wind farm is affected by wind speed as well as wind direction because of the wake effect, so it is possible that power generation loss by downtime is also dependent on combinations of weather conditions (wind speed and direction) and the location of wind turbines for maintenance. In this study, the effects of the wind conditions and the locations of tripped wind turbines on power generation loss were explored for a hypothetical floating offshore wind farm. In order to calculate the power generation of a wind farm, a wake effect calculator was developed based on Jensen's formula. Then, a simple methodology of determining maintenance priorities that minimize power generation loss was proposed.

• Wind and Structures
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• v.20 no.6
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• pp.751-761
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• 2015

A multi-platform offshore wind farm is receiving the worldwide attention for the sake of maximizing the wind power capacity and the dynamic stability at sea. But, its wind power efficiency is inherently affected by the interference of wake disturbed by the rotating blades, so its layout should be appropriately designed to minimize such wake interference. In this context, the purpose of this paper is to introduce a layout optimization for multi-platform offshore wind farm consisted of 2.5MW spar-type floating wind turbines. The layout is characterized by the arrangement type of wind turbines, the spacing between wind turbines and the orientation of wind farm to the wind direction, but the current study is concerned with the spacing for a square-type wind farm oriented with the specific angle. The design variable and the objective function are defined by the platform length and the total material volume of the wind farm. The maximum torque loss and overlapping section area are taken as the constraints, and their meta-models expressed in terms of the design variable are approximated using the existing experimental data and the geometry interpretation of wake flow.

• International Journal of Naval Architecture and Ocean Engineering
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• v.9 no.1
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• pp.45-54
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• 2017

The purpose of this study is to evaluate various means of wind power turbines installation in the Korean west-south wind farm (Test bed 100 MW, Demonstrate site 400 MW). We presented the marine environment of the southwest offshore wind farm in order to decide the appropriate installation vessel to be used in this site. The various vessels would be WTIV (Wind turbine installation vessel), jack-up barge, or floating crane ${\cdots}$ etc. We analyzed the installation cost of offshore wind turbine and the transportation duration for each vessel. The analysis results showed the most suitable installation means for offshore wind turbine in the Korean west-south wind farm.

• Journal of Ocean Engineering and Technology
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• v.33 no.6
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• pp.648-656
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• 2019

The ecological changes in the ocean due to the drastic global warming require that action be taken to sustain the productivity of fisheries. Proper ocean facilities could help prevent the loss of the expenditures made on marine aquaculture and reduce the related compensation for various ocean conditions. The aim of this study was to develop a floating ocean wave-breaker using an eco-friendly concrete and conducting a site survey, a structural analysis, and a test of towing the tank. As a result, the wave at the fish farm would be reduced. The results of the holding power of anchors and the capability of moving the floating structures were considered in the design of the wave-breaker. The analyses of the material properties of concrete and the steel structures, as well as the CAPEX and OPEX analyses of the manufacturing and operation processes confirmed the superiority of the floating concrete wave-breaker. In particular, this study demonstrated that the concrete floating breakwater can protect the fish farm against typhoons and reverse-waves, thereby reducing losses of the fish.

• Journal of Wind Energy
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• v.14 no.1
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• pp.5-13
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• 2023

The commercialization has been of great importance to the clean energy research sector for investing the wind farm development, but it would be difficult to reach a social consensus on the need to expand the economic feasibility of renewable energy due to the lack of reliable and continuous information on levelized cost of Energy (LCOE). Regarding this fact, this paper presents the evaluation of LCOE, focusing on Ulsan offshore region targeting to build the first floating offshore wind farm. Energy production is estimated by the meteorology data combined with the Leanwind Project power curve of an exemplar wind turbine. This work aims to analyze the costs of the Capex depending on site-specific variables. The cost of final LCOE was estimated by using Monte-Carlo method, and it became an average range 297,090 KRW/MWh, a minimum of 251,080 KRW/MWh, and a maximum of 341,910 KRW/MWh. In the year 2021, the SMP (system marginal price) and 4.5 REC (renewable energy certificate) can be paid if 1 MWh of electricity is generated by renewable energy. Considering current SMP and REC price, the floating platform industry, which can earn around 502,000 KRW/MWh, can be finally estimated highly competitive in the Korean market.

• Journal of Wind Energy
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• v.13 no.2
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• pp.5-12
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• 2022

Operations and maintenance (O&M) in offshore wind farms accounts for a substantial portion of the life cycle cost due to harsh weather conditions and vessel dispatching. In this regard, it is crucial to expedite O&M technologies in South Korea, which is in the early stage of harnessing wind resources from the ocean. This contribution investigates an O&M planning and scheduling model for floating offshore wind farms with a literature review and use case study. We introduce the development of a long- and short-term maintenance planning framework as part of an integrated O&M platform. This contains a single vessel and fleets routing composition along with technicians and a maintenance job list based on numerical algorithms. Additionally, the routing search presents the basis of decision support for economic trade-offs regarding smooth operation corresponding to ever-changing wind farm situations. The maintenance planning simulator will ultimately contribute to support yearly and day-to-day power-related decisions in a cost-effective manner.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.6
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• pp.658-665
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• 2019

Among the renewable energy resources, wind power is growing rapidly in terms of technological development and market share. Recently, onshore wind farm have been affected by limitations of terrestrial space and environmental problems. Consequently, installation sites have been moved to the sea, and the development of floating offshore wind farms that are installed at deep waters with more abundant wind conditions is actively underway. In the context of maritime traffic, the optimal site of offshore wind farms is required to minimize the interference between ships and wind turbines and to reduce the probability of accidents. In this study, genetic algorithm based AIS(Automatic Indentification System) data composed of genes and chromosomes has been used. The optimal site of floating offshore wind farm was selected by using 80 genes and by evaluating the fitness of genetic algorithm. Further, the final site was selected by aggregating the seasonal optimal site. During analysis, 11 optimal site were found, and it was verified that the final site selected usng the genetic algorithm was viable from the perspective of maritime traffic.

• Journal of the Korea Society of Computer and Information
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• v.26 no.12
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• pp.255-264
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• 2021

In this paper, we propose operations and maintenance (O&M) planning approach for floating offshore wind farm using the mathematical optimization. To be specific, we present a MILP (Mixed Integer Linear Programming that suggests the composition of vessels, technicians, and maintenance works on a weekly basis. We reflect accessibility to wind turbines based on weather data and loss of power generation using the Jensen wake model to identify downtime cost that vary from time to time. This paper also includes a description of two-stage approach for maintenance planning & detailed scheduling and numeric analysis of the number of vessels and technicians on the O&M cost. Finally, the MILP model could be utilized in order to establish the suitable and effective maintenance planning reflecting domestic situation.