• New & Renewable Energy
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• v.1 no.2 s.2
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• pp.19-25
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• 2005

This study explains ther procedure that should be taken to develp a successful wind park project. It provides a guideline for the activities and studies to be done as a step by step solution. This study follows a chronological flow throughout the whole development Process. This Paper covers technical consideration, assessment of wind energy resource, wind Park siting and energy yield calculation This presented knowledge h3s been mostly gained by the experience from Youngduk wind park project. The further comparison study will be performed between the theoretical prediction and the actual yield of the Youngduk wind park.

• Advances in Energy Research
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• v.6 no.1
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• pp.35-54
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• 2019

A successful blade design must satisfy some criterions which might be in conflict with maximizing annual energy yield for a specified wind speed distribution. These criterions include maximizing power output, more resistance to fatigue loads, reduction of tip deflection, avoid resonance and minimize weight and cost. These criterions can be satisfied by modifying the geometrical parameters of the blade. This study is dedicated to the aerodynamic assessment of a 20 kW horizontal axis wind turbine operating with two possible airfoils; that is $G{\ddot{o}}ttingen$ 413 and NACA 2415 airfoils (the Gottingen airfoil never been used in wind turbines). For this study parameters such as chord (constant, tapered and elliptic), twist angle (constant and linear) are varied and applied to the two airfoils independently in order to determine the most adequate blade configuration that produce the highest annual energy output. A home built numerical code based on the Blade Element Momentum (BEM) method with both Prandtl tip loss correction and Glauert correction, X-Foil and Weibull distribution is developed in Matlab and validated against available numerical and experimental data. The results of the assessment showed that the NACA 2415 airfoil section with elliptic chord and constant twist angle distributions produced the highest annual energy production.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.33 no.5
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• pp.326-333
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• 2009

Design life-time of a wind turbine is required to be at least 20 years. In the meantime, the wind turbine will experience a lot of load cases such as extreme loads and fatigue loads which will include several typhoons per year and extreme gusts with 50 years recurrence period as well as endless turbulence flow. Therefore, IEC61400-1 specifies design load cases to be considered in the wind turbine design and requires the wind turbine to withstand the load cases in various operational situations. This paper investigates the ultimate loads which the wind turbine will experience for 20 years and their characteristics based on the IEC61400-1 using an aero-elastic software, GH-Bladed. And the performance characteristics of a wind turbine such as electrical power generation and annual energy yield are also investigated.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2880-2885
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• 2008

Design lifttime of a wind turbine is required to be at least 20 years. In the meantime, the wind turbine will experience a lot of load cases such as extreme loads and fatigue loads which will include several typhoons per year and extreme gusts with 50 years recurrence period as well as endless turbulence flow. Therefore, IEC61400-1 specifies design load cases to be considered in the wind turbine design and requires the wind turbine to withstand the load cases in various operational situations. This paper investigates the ultimate loads which the wind turbine will experience for 20 years and their characteristics based on the IEC61400-1 using an aero-elastic software, GH-Blade. And the performance characteristics of a wind turbine such as electrical power generation and annual energy yield are also investigated.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.7
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• pp.982-990
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• 2019

The interest of researchers and governments in exploiting tidal energy resources is increasing. Jangjuk strait is a place with high tidal energy density potential and is therefore appropriate for the constructing of a tidal turbine farm. In this study, a numerical approach is presented to evaluate the current flow and power potential in Jangjuk strait with an ADCIRC model. Then, the tidal field characteristics are utilized as input parameters for tidal resource calculation with an in-house program. The 1 MW scale tidal energy converter devices are employed and arranged in 4 layouts to investigate the annual energy yield as well as flow deficit due to the wake ef ect at the surveyed area. The best-performed array generates an annual energy yield up to 12.96 GWh/year (without considering the wake effect); this value is reduced by 0.16 GWh/year when accounting for the energy loss caused by the flow deficit. Moreover, by altering the turbine yaw angle during the flood and ebb tides, the impacts of this factor on the energy extraction are analyzed. This indicates that the turbine array attains the maximum tidal power when the turbine yaw angle is at 346° and 164° (clockwise, to the North) for the spring and neap tide in turns.

• 한국신재생에너지학회:학술대회논문집
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• 2005.06a
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• pp.21-24
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• 2005

This study explains the procedure that should be taken to develop a successful wind park project. It Provide guideline for activities and studies to be done step by step solution. This study follow a chronological flow through the development process. They cover Technical consideration, Assessment of Wind Energy Resource, Wind park siting and Energy yield calculation. It's build on the experience gained by the Youngduk Wind Park project and give the playa role in the development of wind energy projects. It is important to understand all theses issues if a new project is to be successfully completed.

• Environmental Engineering Research
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• v.21 no.3
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• pp.219-225
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• 2016

Energy self-reliance is important for economic growth and development for any nation. An energy self-reliance technological analysis for Kampala the capital city of Uganda is presented. Three renewable energy sources: Municipal Solid Waste (MSW), solar and wind are assessed for the period of 2014 to 2030. Annual MSW generation will increase from $6.2{\times}10^5$ tons in 2014 to $8.5{\times}10^5$ and $1.14{\times}10^6$ tons by 2030 at 2% and 3.9% population growth respectively. MSW energy recovery yield varies from 136.7 GWh (2014, 65% collection) to 387.9 GWh (2030, 100% collection). MSW can at best contribute 2.1% and 1.6% to total Kampala energy demands for 2014 and 2030 respectively. Wind contribution is 5.6% and 2.3% in those respective years. To meet Kampala energy demands through solar, 26.6% of Kampala area and 2.4 times her size is required for panel installation in 2014 and 2030 respectively. This study concludes that improving renewable energy production may not necessarily translate into energy self-reliant Kampala City based on current and predicted conditions on a business as usual energy utilization situation. More studies should be done to integrate improvement in renewable energy production with improvement in efficiency in energy utilization.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.57 no.2
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• pp.132-136
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• 2012

Kenaf (Hibiscus cannabinus) is an annual herbaceous plant of the family Malvacease that has been planted in tropical Africa and Asia region for more than 4000 years and use as source of fiber, energy and feed stock. In this study, the physiological characters and chemical compositions of kenaf mutant variety "Jangdae" developed using gamma irradiation at the Korea Atomic Energy Research Institute (KAERI) were compared with three genetic resources (Auxu, C12, and C14-DRS). Jangdae showed the highest productivity growth rates in fresh yield, dry weight (DW) yield (leaf and stem), node number, and stem thickness. Especially, leaf DW yield of Jangdae was 1.6-3.1 times higher than that of three genetic resources. Also, stem DW yield of Jangdae was 1.6-2.1 times higher than that of three genetic resources. In the analysis of chemical composition, Jangdae showed 16.9% of crude protein content that was 0.86-0.94 times lower than three cultivars. However, Jangdae showed the highest neutral detergent fiber (NDF) contents in leaf (32.5%) and stem (75.2%). Also, acid detergent fiber (ADF) contents of stem and leaf in Jangdae were 64.4% and 33.9%, respectively. Total polyphenol and total flavonoid contents were 22.1 mg/g and 7.4 mg/g in Jangdae. Based on these results, Jangdae would have the potential to become a successful forage crop.

• Current Photovoltaic Research
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• v.10 no.1
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• pp.1-5
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• 2022

Bifacial photovoltaic (PV) technology has received considerable attention in recent years due to the potential to achieve a higher annual energy yield compared to its monofacial PV systems. In this study, we fabricated the bifacial c-Si PV module with a shingled design using the conventional patterned bifacial solar cells. The shingled design PV module has recently attracted attention as a high-power module. Compared to the conventional module, it can have a much more active area due to the busbar-free structure. We employed the transparent backsheet for a light reception at the rear side of the PV module. Finally, we achieved a conversion power of 453.9 W for a 1300 mm × 2000 mm area. Moreover, we perform reliability tests to verify the durability of our Shingled Design Bifacial c-Si Photovoltaic module.

• Fisheries and Aquatic Sciences
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• v.12 no.2
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• pp.118-129
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• 2009

To develop a sustainable management model for oyster farming in Pukman Bay, Korea, we estimated the carrying capacity for oyster farming using food availability data. Optimal culture densities were calculated to be 124-133 individuals per unit flux area ($m^2$) and 310-330 individuals per string. The present annual production is approximately 1,038 tons/year, which is 87% of the estimated maximum yield of 1,193 tons/year. Therefore, considering annual fluctuations and a critical buffer to reduce ecological impacts, the current level is within optimal conditions. During periods of increased water temperature, energy demand was largely met by high primary production. The food supply significantly decreased as the harvest season approached, and 10 out of 21 oyster farms had a deficient food supply for at least 1 month. Therefore, these farms (39% of the farms within the bay) exceeded optimal densities.