• Journal of Navigation and Port Research
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• v.47 no.2
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• pp.106-119
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• 2023

Due to global decarbonization movement and tightening of maritime emissions restrictions, the shipping industry is going to switch to alternative fuels. Among candidates of alternative fuel, methanol is promising for decreasing SOx and CO2 emissions, resulting in minimum climate change and meeting the goal of green shipping. In this study, a novel combined system of direct methanol solid oxide fuel cells (SOFC), proton exchange membrane fuel cells (PEMFC), gas turbine (GT), and organic Rankine cycle (ORC) targeted for marine vessels was proposed. The SOFC is the main power generator of the system, whereas the GT and PEMFC could recover waste heat from the SOFC to generate useful power and increase waste heat utilizing efficiency of the system. Thermodynamics model of the combined system and each component were established and analyzed. Energy and exergy efficiencies of subsystems and the entire system were estimated with participation of the first and second laws of thermodynamics. The energy and exergy efficiencies of the overall multigeneration system were estimated to be 76.2% and 30.3%, respectively. The combination of GT and PEMFC increased the energy efficiency by 18.91% compared to the SOFC stand-alone system. By changing the methanol distribution ratio from 0.05 to 0.4, energy and exergy efficiencies decreased by 15.49% and 5.41%, respectively. During the starting up and maneuvering period of vessels, a quick response from the power supply system and propulsion plant is necessary. Utilization of PEMFC coupled with SOFC has remarkable meaning and benefits.

• Current Photovoltaic Research
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• v.11 no.3
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• pp.79-86
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• 2023

As we strive to mitigate the environmental impact caused by the use of fossil fuels, the exploration of alternative energy sources has gained significant attention. Solar energy, in particular, has emerged as a promising solution due to its eco-friendly nature and virtually limitless availability. Among the various types of solar cells that harness this abundant energy source, organic solar cells have garnered considerable interest. Organic solar cells feature a photo-active layer composed of organic semiconductors, offering a range of appealing advantages such as cost-effectiveness, flexibility, translucency, and the ability to produce customizable colors. However, the commercialization of organic solar cells has been impeded by certain challenges, notably their relatively low efficiency and stability. To overcome these obstacles and pave the way for wider adoption, researchers have been exploring innovative approaches, including the implementation of ternary blend organic solar cells. This strategy involves introducing a third component into the photo-active layer alongside the organic semiconductors, with the aim of enhancing the overall performance of the solar cell. In this paper, we delve into the issues associated with organic solar cells and focus on one potential solution: ternary blend organic solar cells. Specifically, we examine the application of this approach to PM6:Y6, which stands as one of the most popular combinations of organic semiconductors. By investigating the potential of ternary blends, particularly utilizing PM6:Y6, we aim to accelerate the commercialization of organic solar cells.

• Clean Technology
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• v.16 no.3
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• pp.182-190
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• 2010

The feasibility of clean technology to minimize the $CO_2$ emission by recycling and reuse the waste materials and energy have been studied for the cement industry. A life cycle assessment (LCA) was performed for an alternative raw material-supply method to use the molted slag as the major raw material in the cement clinker manufacturing. Using this new method, a 60% of $CO_2$ could be reduced that comes out during the decarboxylation from the cement rotary kiln. The energy-efficiency improvement and the alternative energy methods that had been determined in our previous study through the environmental assessment of cement industry were applied to the study for the reduction of $CO_2$ emission. The natural gas, one of the fossil fuels, was also used as the first choice to get the result at the earliest time by the most economic and the most efficient green technology and to switch into the carbon neutral energy consumption pattern.

• Journal of Energy Engineering
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• v.18 no.3
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• pp.191-202
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• 2009

South Korea, ranks 10th largest emitter of carbon dioxide in the world, will probably be under the obligation to reduce GHG emission from 2013. It is very important to reduce the electrical energy consumption since 30% of GHG emission in South Korea is made during electricity generation. In this study, based on "the 1st national energy master plan", the GHG emission reduction potential and the feasibility of the scenario in the electricity generation have been analyzed using LEAP(Long-range Energy Alternative Planning system). The scenario of the mater plan contains the 41% expansion of nuclear power plant facilities and the 11% diffusion of renewable energy until 2030. In result, total $CO_2$ emission reduction rate is 28.8% in 2030. Also $CO_2$ emission of unit electricity generation of bituminous coal power plant is $0.85kgCO_2/kWh$ and its LNG power plant is $0.51kgCO_2/kWh$ in BAU scenario. Therefore when existing facilities is exchanged for nuclear or renewable energy power plant, substitute of bituminous power plant is more effective than LNG power.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.2
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• pp.335-338
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• 2012

Recently, the energy has been used much more than ever, but there has been many problems including atmospheric pollution. So we need alternative energy resources, which are solar heat, solar light, wind power, small water power, etc. The field, which is most popular these days, is the energy source by solar light which transform electric energy using the solar cell and it is available with many researches. In this paper, we manufactured the solar power generation system over 90W using solar module which was 9.90V for Voc, 0.93 A for Isc, 8.64 V for Vmp, 0.75 A for Imp, 6.5 W for power. System was controlled by step motor with worm gear to operate optimum condition between $0^{\circ}{\sim}70^{\circ}$ angle. This system was very effective in tracking space use because it need less space than general solar module.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.238.2-238.2
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• 2010

Recently, environmental pollution and energy depletion problems have been issued over the world. For this reason, many renewable systems have been developing. Of these, the Ocean Thermal Energy Conservation(OTEC) is drawing attention as the upcoming alternative energy source. In this paper, the efficiency of each of OTEC which harness the effluent from nuclear power plant was analyzed by using computer calculation. The result, shows that Ul-jin Nuclear Power Plant is the best place geographically and the regenerative cycle is most outstanding performance cycle for OTEC. The difference of temperature between surface water and deep water temperature should be greater than $20^{\circ}C$ in order to increase the efficiency.

• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.59-61
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• 1996

Fuel cell systems offer high efficiencies for energy conservation for transportation application. In addition, they can operate on alcohols and alternative fuels, while producing little or no noxious emissions. The goal of the fuel cell in transportation should be research and commercialization of fuel cell vehicles as economic competitors for internal combustion engine vehicle. The objective of the present study is to analyze feasibility of the fuel cell/battery combination as a power source for a bus.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.12 s.189
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• pp.72-79
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• 2006

Vibration of a non-linear system under random parametric excitations was evaluated by probabilistic methods. The non-linear characteristic terms of a system structure were quasi-linearized and excitation terms were remained as they were An analytical method where the square mean of error was minimized was used An alternative method was an energy method where the damping energy and restoring energy of the linearized system were equalized to those of the original non-linear system. The numerical results were compared with those obtained by Monte Carlo simulation. The comparison showed the results obtained by Monte Carlo simulation located between those by the analytical method and those by the energy method.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.557-560
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• 2009

When we urgently need to develop and supply an alternative energy, wind power is growing with much interest because it has relative low cost of power and area of tower. To estimate the wind power resource, it is necessary to make an observation first. Although the large wind falm and resources are near coast and mountain area, the wind energy in urban area has the strong thing of direct access to power generator. In this study, we estimate the probability of wind energy above urban area using SODAR data, which is located at the top of the tall building (140m).

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.235-238
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• 2009

It is necessary to estimate empirical constants in order to predict the monthly mean daily global radiation on a horizontal surface in the developing areas for alternative energy. Therefore many different equations have proposed to evaluate them for certain areas. In this work a new correlation has been made to predict the solar radiation for any areas over Korea by calculating the regression models taking into account latitude, percentage of possible sunshine, and cloud cover. From the results, the single linear equation proposed by using percentage of possible sunshine method shows reliable results for estimating the global radiation with average annual deviation of -3.1 to +0.6 % from measured values