• Journal of Advanced Marine Engineering and Technology
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• v.37 no.3
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• pp.266-273
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• 2013

With the worldwide trend of controlling the utilization of fossil fuels inducing global climate change, many efforts will have to be made on securing a sustainable energy supply. Tidal current is a concentrated form of gravitational energy, its resource is significant, but limited locations. To effectively capture tidal current energy from the sea, a group of tidal turbines should be formed and positioned with optimal size and spacing for absorbing from multiple points. Thus, the flow field including turbines becomes a huge domain, a so-called tidal farm. It can be very convenient technically and economically if a whole turbine farm is simulated by means of actuator disc thoery. So, the analysis method using actuator discs coupled with a solution of Reynolds Averaged Navier-Stokes (RANS) equations is adopted for actual tidal turbines. Actuator discs have regions where similar forces imposed by actual turbines are applied to a flow. As working in group formation, turbines naturally have interaction effects on one another. Therefore, the present paper investigate the evaluation on the operating performance of tidal farm in terms of the mutual influence among turbine units with various lateral and longitudinal spacing. Authors expect that results of the present study contribute to the development of tidal farm for the future potential energy.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2012.06a
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• pp.155-156
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• 2012

In the modern age, as man's demand of energy is continuously grew, tidal becomes one of the sustainable energy sources that have been investigating thoroughly recently. Tidal turbine has proved high potential as a future power-generating device. To effectively capture tidal energy on site, a group of tidal turbines should be used and positioned in some formation with proper size and space so that energy can be absorbed from multiple point. Thus, the turbines together with the flow filed becomes a huge domain, a tidal farm. So, it becomes more convenient if a whole turbine farm is simulated by means of actuator discs since the time and cost for analysis can be reduced. This paper aims to evaluate the operating performance (power efficiency and energy restoration rate), mutual influence (for different longitudinal and lateral spaces), the influence of velocity profiles, turbulence intensity and the far wake characteristic of tidal turbines operating in farm formation. The results of this study help contributing to the present development of tidal turbine as the future potential energy conversion machinery.

• Journal of Ocean Engineering and Technology
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• v.23 no.1
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• pp.109-113
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• 2009

Several tidal current power plants are being planned and constructed in Korea utilizing the strong tidal currents along the west and south coasts. A tidal current reaches 9.7 m on the west coast; there are few potential regions for tidal current power generation. The construction of a dam to store water can prevent the circulation of water, causing a great environmental impact on the coast and estuary. The tidal barrage could produce a large amount of power, but it should be carefully considered. The purpose of developing renewable energies is to minimize the environmental impact and to maximize the utilization of clean energy. To produce a great quantity of power, tidal current farms require the placement of numerous units in the ocean. The power generation is very dependent on the size of the rotor and the incoming flow velocity. Also, the interactions between devices contribute greatly to the production of power. The efficiency of a power farm is estimated to determine the production rate. This paper introduces 3 D interaction problems between rotating rotors, considering the axial, transverse, and diagonal distances between horizontal axis tidal current devices.

• Journal of the Korean Society of Marine Environment & Safety
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• v.19 no.1
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• pp.85-92
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• 2013

Many efforts will have to be made on securing the stable supply of the energy due to the worldwide trend of controlling the utilization fossil fuels inducing global climate change. Renewable portfolio standard enforced to power companies over 500 MW capacity from 2012. Tidal current energy is one of the most interesting renewable and clean energy resources that have been less exploited. Especially, Korea has worldwide outstanding tidal current energy resources and it is highly required to develop a tidal current energy conversion system(TECS) in coastal region. So, we examine a tidal in-stream energy using a numerical model and estimate a tidal current potential for commercialization of tidal current power plant in the sea of the Bunamgun-do. Available tidal energy resources is also analytically estimated using a tidal farm method and the annual energy production of an optimal TECS arrays will be calculated with taking into account interference of lateral and longitudinal spacing.

• The KSFM Journal of Fluid Machinery
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• v.19 no.4
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• pp.54-62
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• 2016

This study presents an approach of tidal farming optimization using a numerical modelling method to simulate tidal energy extraction for 1MW scale tidal stream devices around Jangjuk-sudo, South Korea. The utility of the approach in this research is demonstrated by optimizing the tidal farm in an idealized scenario and a more realistic case with three scenarios of 28-turbine centered tidal array (named A, B and C layouts) inside the Jangjuk-sudo. In addition, the numerical method also provides a pre-processing calculation helps the researchers to quickly determine where the best resource site is located when considering the position of the tidal stream turbine farm. From the simulation results, it is clearly seen that the net energy (or wake energy yield which includes the impacts of wake effects on power generation) extracted from the layout A is virtually equal to the estimates of speed-up energy yield (or the gross energy which is the sum of energy yield of each turbine without wake effects), up to 30.3 GWh/year.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.169.1-169.1
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• 2010

Due to global warming, the need to secure an alternative resource has become the international issue. Not like other renewable energy sources, TCP is the high reliable and predictable and continuous energy source as the current pattern and speed can be predicted throughout the year. Having very strong tidal current speeds, there are many suitable site for the application of TCP (Tidal Current Power) on the west and south coastal region in Korea. The maximum current speed in the south is recorded up to 6.5m/s. Due to the high tidal current speed on the west coast of Korea, numerous tidal current projects are being planned. To extract a significant quantity of power, a tidal current farm with number of devices is required in the ocean. However, it is important to estimate the potential quantity of energy in the area. Also the realistic quantity that can be extracted is to be investigated. Based on the estimated energy production considering the number of devices and the interactional effects, system type, the water depth and etc., the cost of the development and the benefit from SMP can be estimated. The feasibility study for the 200MW tidal in Incheon, Korea has been performed recently. Based on the actual feasibility study, the procedure and the key points for the application of tidal current power farm are introduced in the paper.

• Korean Journal of Agricultural Science
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• v.27 no.2
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• pp.141-157
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• 2000

This study is aimed at identifying the socio-economic value of the total area of 23,500ha of paddy field which will be reclaimed in year 2003. In Korea, tidal land reclamation projects has been carried out not only for paddy field expansion to meet national food security but also for national land expansion to cope with the shortage of land supply in implementing urbanization and industrialization. As of end of 1999, 75,738ha of tidal land reclamation, 48.3%, out of 156,666ha has been carried out in Korea. In spite of continuous implementation of tidal land reclamation, 48.3%, out of 156,666ha has been carried out in Korea. In spite of continuous implementation of tidal land reclamation projects, the appraisal of the national land expansion value has not been made even though the severe competitiveness of land use in economic development. Agricultural land about 20,000 - 30,000ha per year has been converted to urban and industrial land and the converted areas have been produced higher added value than that of the farm land. Accordingly, farm land expansion equivalent to the converted area have to be reclaimed to cope with the food shortage and security in the future. In relation to the study, demand and supply of rice, the staple food of Korean, has been projected up to year 2025. The study results are as follows: 1. Under the assumption of continuing the present tendencies of rice consumption, population increase, farming practices and farm land conversion, paddy area requirement to meet self sufficiency of rice were forecasted as 136,950ha in 2015, 193,460ha in 2020 and 218,482ha in 2025 respectively. 2. The average converted price of paddy per pyeong in Kimje city, Puna Gun and Gunsan city was estimated at 241,150won and average farm land price was amounted to 63,760won. The differential rent was estimated at 177,400won per pyeong which was used as a criteria for valuation of national land expansion effect of the tidal land reclaimed by Saemangeum project. The total land rent of 23,250ha expanded by tidal land reclamation was amounted to 12,361 billion won. Annual expected value of the expanded national land was estimated at 988.9 billion won considering 8% of annual discount rate in Korea. 3. Tidal land resource for paddy area development is limited comparing with the future requirement of paddy area to cope with self sufficiency of rice consumption. Accordingly farm land conversion to urban and industrial land should be regulated and protected in the sense of sustainable development in the future.

• KCID journal
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• v.21 no.1
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• pp.1-16
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• 2014

The purpose of this study is to calculate agricultural water demand as considering landuse plan of the farm land on the Saemangeum tidal land reclamation project. This study based on the farm landuse plan(2012) and considered some items which did not included previous work like prevention water for resalinization for paddy and upland and muli-purpose water for upland. This study showed that the agricultural water demand estimated $145.123Mm^3/yr$, which is needed as much $14.792Mm^3/yr$ as more water than previous work. The difference comes from the change of unit water demand. Water demand is possible to be changed if guidelines are improved and detailed design work is completed through further study. Especially, the more studies for prevention water for resalinization in a tidal reclaimed farmland and water demand for a horticulture are needed.

• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.5
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• pp.484-491
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• 2015

The productivity of Manila clam(Ruditapes philippinarum) aquaculture farm is closely related to suitable site selection, so it is essential to assess the habitat suitable for aquaculture species in order to manage yield. This study evaluated the habitat suitable index(HSI) with 9 sites for tidal flat farm, Gochang(Hajun) on May 2014. The suitability index was selected Growth(hydrodynamics, chlorophyll a), Survival(sediment-sand, silt-clay) and Water Environment(dissolved oxygen, salinity). Both Weight and No weight were tried for objective judgment as HSI scoring method. As a result, it shows lower tidal flat(HSI; No weight: 0.60~0.76, Weight: 0.47~0.70) is higher than upper(HSI; No weight: 0.25~0.27, Weight: 0.09~0.10), hydrodynamics and sediment particle size are the most effective. This research can consider the potential suitable site for Manila clam through scientific approach, and provide the basis for optimal management practices in tidal flat farm.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.163.2-163.2
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• 2011

Due to global warming, the need to secure an alternative resource has become more important nationally. Due to the high tidal range of up to 9.7m on the west coast of Korea, numerous tidal current projects are being planned and constructed. To extract a significant quantity of power, a tidal current farm with a multi-arrangement is necessary in the ocean. The rotor, which initially converts the energy, is a very important component because it affects the efficiency of the entire system, and its performance is determined by various design variables. The power generation is strongly dependent on the size of the rotor and the incoming flow velocity. However, the interactions between devices also contribute significantly to the total power capacity. Therefore, rotor performance considering the interaction problems needs to be investigated for generating maximum power in a specific field. This paper documents the characteristics of wake induced by horizontal axis tidal current power turbine.