• New & Renewable Energy
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• v.4 no.3
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• pp.5-14
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• 2008

The target for the reduction of $CO_2$ emissions, as specified in the Kyoto Protocol, can only be achieved by an extended use of renewable fuels and the increasing of the energy efficiency. The energy generation from waste gases with a reasonable content of methane like biogas can significantly contribute to reach this target. A further reduction of greenhouse gas emissions is possible by increasing the electrical efficiency using progressive technologies. Fuel cells can be highly energy conversion devices. Utilizing biogas as the fuel for fuel cell systems offers an option that is technically feasible, potentially economically attractive and greenhouse gas neutral. High temperature fuel cells that are able to operate with carbon monoxide in the feed are well suited to these applications. Furthermore, because they do not require noble metal catalysts, the cost of high-temperature fuel cells has the greatest potential to become competitive in the near future compared to other types of fuel cells.

• 한국태양에너지학회:학술대회논문집
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• 2011.04a
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• pp.235-240
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• 2011

Small hydropower resources for five major river systems have been studied. The model, which can predict flow duration characteristic of stream, was developed to analyze the variation of inflow caused from rainfall condition. And another model to predict hydrologic performance for small hydropower(SHP) plants is established. Monthly inflow data measured at Andong dam were analyzed. The predicted results from the developed models in this study showed that the data were in good agreement with measured results of long term inflow at Andong darn. It was found that the models developed in this study can be used to predict the available potential and technical potential of SHP sites effectively. Based on the models developed in this study, the hydrologic performance for small hydropower sites located in river systems have been analyzed. The results show that the hydrologic performance characteristics of SHP sites have some difference between the river systems. Especially, the specific design flowrate and specific output of SHP sites located on North Han river and Nakdong river systems have large difference compared with other river systems.

• 한국태양에너지학회:학술대회논문집
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• 2009.04a
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• pp.139-144
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• 2009

The generation of small hydropower as compared to other different developed environmental methods produces one of the clean energies. In such manner, various application system development through IT technique is being developed for an advanced small hydropower energy resources data mining. However, existing data analysis of New & Renewable Information System for small hydropower resources application is incomplete therefore it limits expressing these information on the Web. Thus for positive usage of small hydropower resources, a more systematic and precise analysis system should be built. This study seeks to develop a map of the domestic small hydropower resources problems to further improve small hydropower resources, developed through Package Tool which can accurately evaluate a wide range of small hydropower basin in a short period of time. Small hydropower Package Tool was calculated using existing Analysis System small hydropower resources which did not provide diverse capabilities resulting to 840 standard basin classified by A and facility capacity, etc., and to assume a 40% annual capacity, expected annual electricity production was calculated. Small hydropower for the national water system of small hydropower resources potential calculated in terms of resources for the development of small hydropower will be utilized as basic data.

• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.435-438
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• 2009

Wind speed is measured on the nacelle at the location of wind turbines are installed. The wind speed is transformed to inlet wind speed at the front of hub using newly developed algorithm derived from energy conservation. Wind energy potential is analyzed using the inlet air velocity in the region of Bieung-do wind farm. As results, wind speed depending on the month, yearly averaged wind speed, wind speed distribution, and energy density are showed in this study. Bieung-do area is close to Saemankeum, and the analysis of wind energy potential in Bieung area will be helpful to understand and develop wind energy industry in Saemankeum area.

• Carbon letters
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• v.20
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• pp.47-52
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• 2016

Physical and electrochemical qualities were analyzed after KOH activation of a direct methanol fuel cell using needle coke as anode supporter. The results of research on support loaded with platinum-ruthenium suggest that an activated KOH needle coke container has the lowest onset potential and the highest degree of catalyst activity among all commercial catalysts. Through an analysis of the CO stripping voltammetry, we found that KOH activated catalysis showed a 21% higher electrochemical active surface area (ECSA), with a value of 31.37 m² /g, than the ECSA of deactivated catalyst (25.82 m² /g). The latter figure was 15% higher than the value of one specific commercial catalyst (TEC86E86).

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.151-151
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• 2021

The alarming climate change impacts are demanding the use of renewable energy sources like never before. Hydropower is one of the most cost-effective and environmental friendly energy technology recognized in the world. Big hydropower projects come up with the requirements of huge investment costs along with environmental impacts, whereas small hydropower(SHP) are considered a best solution for the economical source of energy. SHP, basically Run-of-River (RoR) type plants can be sustainable renewable energy sources and given the nature of perennial rivers flowing from steep gradient and rugged topography, feasibility of such plants is equally high in Nepal. The objective of this study is to determine the primary potential sites for the development of RoR type SHP sites using Geo-spatial Information System(GSIS). The use of GSIS enables precise survey of large area within a short period of time. This study has focused on the determination of locations by establishing defined criterions and methodologies and hence have located multiple locations rather than selecting one best location. The approach is applicable for the rapid initial screening of potential locations and results can facilitate detail feasibility study for the technical and economic analysis of SHP in the basin.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2011.06a
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• pp.79-79
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• 2011

The oceans are an untapped resource, capable of making a major contribution to our future energy needs. In the search for a non polluting renewable energy source, there is a push to find an economical way to harness energy from the ocean. Tidal stream is one of ocean energy form that is being investigated as potential source for power generation. Tidal current turbines are therefore designed as conversion machinery to generate power from tidal currents. A study on energy extraction from tidal currents is presented in this paper.

• Current Photovoltaic Research
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• v.8 no.4
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• pp.114-119
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• 2020

In this study, Mitigation of Potential-induced degradation (PID) for PERC solar cells using SiO2 Structure of ARC layer. The conventional PID test was conducted with a cell-level test based on the IEC-62804 test standard, but a copper PID test device was manufactured to increase the PID detection rate. The accelerated aging test was conducted by maintaining 96 hours with a potential difference of 1000 V at a temperature of 60℃. As a result, the PERC solar cell of SiO2-Free ARC structure decreased 22.11% compared to the initial efficiency, and the PERC solar cell of the Upper-SiO2 ARC structure decreased 30.78% of the initial efficiency and the PID reliability was not good. However, the PERC solar cell with the lower-SiO2 ARC structure reduced only 2.44%, effectively mitigating the degradation of PID. Na+ ions in the cover glass generate PID on the surface of the PERC solar cell. In order to prevent PID, the structure of SiNx and SiO2 thin films of the ARC layer is important. SiO2 thin film must be deposited on bottom of ARC layer and the surface of the PERC solar cell N-type emitter to prevent surface recombination and stacking fault defects of the PERC solar cell and mitigated PID degradation.

• 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.

• Architectural research
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• v.18 no.2
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• pp.59-64
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• 2016

Since the massive power outages that hit across the nation in September 2011, a growing imbalance between energy supply and demand has led to a severe backup power shortage. To overcome the energy crisis which is annually repeated, a policy change for deriving energy supply from renewable energy sources and a demand reduction strategy has become essential. Buildings account for 18% of total energy consumption and have great potential for energy efficiency improvements; it is an area considered to be a highly effective target for reducing energy demand by improving buildings' energy efficiency. In this regard, retrofitting buildings to promoting environmental conservation and energy reduction through the reuse of existing buildings can be very effective and essential for reducing maintenance costs and increasing economic output through energy savings. In this study, we compared the energy reduction efficiency of national power energy consumption by unit production volume based on thermal power generation, renewable energy power generation, and initial and operating costs for a building retrofit. The unit production was found to be 13,181GWh/trillion won for bituminous coal-fired power generation, and 5,395GWh/trillion won for LNG power generation, implying that LNG power generation seemed to be disadvantageous in terms of unit production compared to bituminous coal-fired power generation, which was attributable to a difference in unit production price. The unit production from green retrofitting increased to 38,121GWh/trillion won due to the reduced energy consumption and benefits of greenhouse gas reduction costs. Renewable energy producing no greenhouse gas emissions during power generation and showed the highest unit production of 75,638GWh/trillion won, about 5.74 times more effective than bituminous coal-fired power generation.