• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.196.2-196.2
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• 2011

지구온난화와 화석연료 고갈에 대한 우려로 전세계적으로 신재생에너지의 개발 및 활용이 본격화되고 있다. 특히, 다양한 신재생에너지원 중에서 날씨 및 계절에 의한 영향, 기저부하 담당, 지상 점유 면적, 소음 등 생활환경 영향, 경제성 등을 고려할 때 지열에너지는 미래 청정에너지원로서 기대와 관심이 집중되고 있다. 화산이 존재하지 않는 우리나라에서의 지열발전은 거의 불가능한 것으로 인식되어 지금까지의 심부 지열에너지 개발 프로젝트는 대부분 지역난방, 시설영농 등 직접이용을 목표로 추진되어 왔다. 그러나, 2003년부터 한국지질자원연구원에서 수행한 포항 심부지열에너지 개발사업의 결과로 얻어진 다양한 지질학적/지열학적 증거들을 토대로 분석한 결과, 국내 일부 지역에서는 지하 5 km 심도에서 최대 약 $180^{\circ}C$의 지온이 예상되어 국내에서도 심부 지열에너지를 이용한 지열발전에 대한 가능성이 제기되어 왔다. 여기에, 유럽과 미국 그리고 호주 등 선진국을 중심으로 비화산 지역에서 지하 심부에 인공적으로 지열저류층(파쇄대)을 생성하고 이를 통해 열매체(물)를 순환시킴으로써 생산된 증기를 발전에 활용하는 EGS (Enhanced Geothermal System) 기술이 개발되고 몇몇 성공사례가 발표되었다. 또한, 이러한 기술개발에 힘입어 EGS 지열발전에 대한 선진국의 과감한 연구비 투자가 이어졌다. 이러한 기술적 배경에 발맞추어 우리나라에서도 2010년 12월에 EGS 지열발전 과제가 착수되었다. 이 프로젝트는 아시아에서는 최초로 수행되는 EGS 기술 개발과제로서 2015년까지 약 480억원의 R&D 예산을 투입하여 MW급의 지열발전 pilot plant의 구축을 목표로 하고 있다. 프로젝트가 성공적으로 추진될 경우 국내외적인 파급효과는 매우 클것이다. 특히 2015년까지 1.5 MW의 pilot plant의 구축이 성공적으로 추진될 경우 국내에서는 2017년까지 3 MW 이상, 2020년까지 20 MW이상, 2030년까지 200 MW 이상의 지열발전이 가능할 것으로 기대된다. 또한 축적된 기술개발 경험을 바탕으로 인도네시아, 필리핀 등의 해외의 지열발전 사업에도 진출할 수 있는 계기가 될 것이다. 프로젝트는 넥스지오를 주관기관으로 하고 한국지질자원연구원, 한국건설기술연구원 및 서울대학교 등의 지질자원 관련 연구 및 교육기관과 포스코, 이노지오테크놀로지 등의 산업체가 참여하여 컨소시엄 형태로 추진하고 있으며, 향후 관심있는 여러 기관 및 산업체의 지원과 참여를 기대한다.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.49.1-49.1
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• 2011

집광채광 설비는 건축물의 조명에너지 절감 및 자연광의 실내 유입을 위해 적용 가능한 태양에너지설비로써 다른 신 재생 에너지 설비와 다르게 연간에너지생산에 대한 정량적 데이터가 아직까지 부재하다. 집광채광 설비의 설치효과를 판단하기 위해서는 집광채광 설비 설치에 따른 연간 에너지생산량 산출이 필요하며, 이를 위해서는 각 구성부분(집광부, 전송부 및 산광부)의 광전송 효율에 대한 데이터가 구축되어야 한다. 본 연구는 집광채광 설비의 효율 분석에 관한 첫 번째 단계로써 외부광속에 대한 집광부 통과 직후의 내부광속의 비율을 예측하였다. 국내에 보급된 집광채광 설비는 대부분 프리즘형과 광덕트형이며, 우선적으로 집광부 입사면의 경사각과 방위각이 다양하여 내부광속 산출방법론이 매우 복잡한 프리즘형을 분석대상으로 삼았다. 전일사량, 외부조도 및 집광부 내부조도가 측정되었으며, 외부광속으로부터 내부광속을 산출하는 공식을 유도하기 위해 천공상태에 따라 전일사량 측정치가 직산분리 되었다. Perez model과 Liu and Jordon에 의해 제시된 계산식과 입사면 및 집광부 면적을 고려하여 수평면 외부조도 측정치로부터 외부광속이 그리고 내부조도로부터 내부광속이 산출되었다. 입사면의 투과율이 동일하다는 전제 하에 천공상태에 따른 태양광 투과 비율을 도출한 결과, 담천공(Kt ${\leq}$ 0.3)에서 0.39, 부분담천공(0.3${\geq}$ 0.78)에서 1.0으로 나타났다. 도출된 투과비율을 외부광속에 적용하여 내부광속을 계산한 결과치와 측정치는 약 ${\pm}9%$ 정도의 차이를 보였다. 연간 기상데이터에 위와 같은 방법론이 적용되면 프리즘형 집광부의 연간 내부광속이 산출될 수 있다. 또한 기존 연구에서 제시된 발광효율 산출식과 일사 파장에 따른 시감도를 고려하면 매 시간별 외부조도도 산출이 가능하다. 일사량 측정치와 외부조도 측정치 사이의 상관관계를 분석한 결과 결정계수 $R^2$이 0.99인데 반해 일사량 측정치와 외부조도 계산치 사이의 상관관계 결정계수는 0.95로 측정치 보다 약간 작은 값을 갖는다. 이렇게 산출된 외부조도는 각 입사면의 면적을 반영하여 외부광속으로 변환되고, 앞서 산출된 천공상태별 투과비율이 적용됨으로써 내부광속이 도출될 수 있다. 이와 같은 집광부에 대한 연구를 바탕으로 향후 전송부와 산광부 효율을 도출하고 궁극적으로 집광채광 설비를 통해 실내에 전달되는 연간 빛에너지를 예측할 수 있을 것이다. 또한 본 연구의 방법론은 다른 형태의 집광채광 설비에도 적용이 가능할 것으로 판단되며, 국내 집광채광 설비의 연간 에너지생산량에 대한 폭 넓은 데이터 구축이 가능할 것으로 기대된다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.5
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• pp.379-387
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• 2016

The goal of this research is to identify the planning techniques of high-rise housing estates applying a smart green city concept in order to understand the necessity of integrating 'planning & building' planning techniques and 'smart system' planning techniques and to analyze the current status of application. For the research, firstl, the definition of smart green city was established and high-rise housing estates planning was categorized according to a three space hierarchy, seven planning directions and 17 major features through literature review. Second, 28 'planning & building' planning techniques and 'smart system' planning techniques were derived through literature review and FGI analysis. Last, four cases in Multi-functional Administrative City were analyzed for the current status of application of planning techniques. In conclusion, planning techniques in 'Transportation Network', 'Environment-friendly layout planning of housing', 'Revitalization of green transportation', 'Utilization of new & renewable energy', 'Crime prevention and accident reduction', 'Use of high performance, and efficiency facility' main feature were identified as important planning techniques for Smart Green City and its implications were estimated.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.1
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• pp.76-85
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• 2023

Demand for hydrogen as a renewable energy resource is increasing. However, unlike conventional fossil fuels, hydrogen requires a dedicated refueling station for fuel supply. A risk assessment of hydrogen refueling stations must be undertaken to secure the infrastructure. Therefore, in this study, a risk assessment for hydrogen refueling stations was conducted through both qualitative and quantitative risk assessments. For the qualitative evaluation, the hydrogen dispenser module was evaluated as two nodes using the hazard and operability (HAZOP) analysis. The risk due to filter clogging and high-pressure accidents was evaluated to be high according to the criticality estimation matrix. For the quantitative risk assessment, the Hydrogen Korea Risk Assessment Module (Hy-KoRAM) was used to indicate the shape of the fire and the range of damage impact, and to evaluate the individual and social risks. The individual risk level was determined of to be as low as reasonably practicable (ALARP). Additional safety measures proposed include placing the hydrogen refueling station about 100m away from public facilities. The social risk level was derived as 1E-04/year, with a frequency of approximately 10 deaths, falling within the ALARP range. As a result of the qualitative and quantitative risk assessments, additional safety measures for the process and a safety improvement plan are proposed through the establishment of a restricted area near the hydrogen refueling station.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.10a
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• pp.582-583
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• 2021

As the production of new and renewable energy such as solar and wind power has diversified, microgrid systems that can simultaneously produce and consume have been introduced. . In general, a decrease in electricity prices through solar power is expected in summer, so producer protection is required. In this paper, we propose a transparent and safe gift power transaction system between users using blockchain in a microgrid environment. A futures is simply a contract in which the buyer is obligated to buy electricity or the seller is obliged to sell electricity at a fixed price and a predetermined futures price. This system proposes a futures trading algorithm that searches for futures prices and concludes power transactions with automated operations without user intervention by using a smart contract, a reliable executable code within the blockchain network. If a power producer thinks that the price during the peak production period (Hajj) is likely to decrease during production planning, it sells futures first in the futures market and buys back futures during the peak production period (Haj) to make a profit in the spot market. losses can be compensated. In addition, if there is a risk that the price of electricity will rise when a sales contract is concluded, a broker can compensate for a loss in the spot market by first buying futures in the futures market and liquidating futures when the sales contract is fulfilled.

• Journal of the Korean Society for Marine Environment & Energy
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• v.19 no.3
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• pp.227-235
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• 2016

This paper emphasized the necessity of the marine spatial planning (MSP) through the analysis of the major developmental projects which could make a contradiction based on the adequacy of the site selection and environmental impacts. The conflicting affairs between space utilization and management plan happen in the following ways: marine renewable energy development, sand mining, reclamation, construction of golf course in coastal area, thermal effluent and waste heat, erosion causing port development. The conflict of stakeholder continues caused by the accumulated environmental impact. For the reasons mentioned above, we found two things. First, it is necessary to comprehend the fact of developmental planning and MSP. Second, it is still unsatisfactory to connect the relevance of laws related to the spatial planning. For the reinforcement of marine environmental policy management, it is necessary to consolidate the property of site selection and assessment of developmental scale. Especially, while the strategic environmental assessment is in progress based on site selection and property of scale, consistent diagnosis is needed in the following concerns: the fact of the marine spatial planning, the relevance between national developmental plan and regional developmental plan, fisheries regulation, marine protected animals. For the environmentally sound and sustainable development (ESSD), MSP should have to be prepared based in a way of top-down including coastal and EEZ plan, relevance of ocean-use zoning and sector planning, 3-D spatial information. And also integrated information system have to be prepared through high-tech marine spatial information. In conclusion, consistent and relevant strategy for MSP should have to include the whole information related to the maritime affairs such as harbor, fishing port, fishing ground, coastal management, marine ecosystem generally.

• Journal of Advanced Marine Engineering and Technology
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• v.41 no.1
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• pp.31-35
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• 2017

The internal flow of a pump system that is installed in the interior of large vessels such as tankers is largely affected by the water level and flow conditions of the pump sump. However, the performance of the pump is generally evaluated with the consideration of only the performance of the pump itself, without considering the pumping station operating environment. Therefore, if the pump is affected by the incoming flow that exhibits vortex and swirl, the occurrence of vortex and swirl accompanied with air may cause problems with the pump sump. This effect of flow condition can lead to a decrease in efficiency, increase in vibration, and noise generation in the pump. In this study, to investigate the internal flow of the pump sump according to several water levels, a pump sump scale-model was designed and constructed. The frequency of vortex occurrence and the shape of the vortex were investigated according to the different water levels of a fundamental test. The Class C vortex type, which has a larger volume of air intake to the pump, was confirmed by the higher occurrence frequency at a relatively lower water level.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.127.1-127.1
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• 2011

In this paper, ZnO:Al thin films with c-axis preferred orientation were prepared on Soda lime glass substrates by RF magnetron sputtering technique. AZO thin film were prepared in order to clarify optimum conditions for growth of the thin film depending upon process, and then by changing a number of deposition conditions and substrate temperature conditions variously, structural and electrical characteristics were measured. For the manufacture of the AZO were vapor-deposited in the named order. It is well-known that post-annealing is an important method to improve crystal quality. For the annealing process, the dislocation nd other defects arise in the material and adsorption/decomposition occurs. The XRD patterns of the AZO films deposited with grey theory prediction design, annealed in a vacuum ambient($2.0{\times}10-3$Torr)at temperatures of 200, 300, 400 and $500^{\circ}C$ for a period of 30min. The diffraction patterns of all the films show the AZO films had a hexagonal wurtzite structure with a preferential orientation along the c-axis perpendicular to the substrate surface. As can be seen, the (002)peak intensities of the AZO films became more intense and sharper when the annealing temperature increased. On the other hand, When the annealing temperature was $500^{\circ}C$ the peak intensity decreased. The surface morphologies and surface toughness of films were examined by atomic force microscopy(AFM, XE-100, PSIA). Electrical resistivity, Gall mobility and carrier concentration were measured by Hall effect measuring system (HL5500PC, Accent optical Technology, USA). The optical absorption spectra of films in the ultraviolet-visibleinfrared( UV-Vis-IR) region were recorder by the UV spectrophotometer(U-3501, Hitachi, Japan). The resistivity, carrier concentration, and Hall mobility of ZnS deposited on glass substrate as a function of post-annealing.

• 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 Cadastre & Land InformatiX
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• v.48 no.1
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• pp.5-14
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• 2018

Recently the construction of solar plant showed a steady growth in influence of renewable energy policy. It is very important to determine the optimal location and aspect of solar panel using analyzed data of solar radiation to solar plant area beforehand. This study analyzed solar radiation in solar plant area using DEM acquired from UAV geospatial information. Mean solar radiation of 2017 was calculated as $1,474,466W/m^2$ and total solar radiation of 2017 considering solar plant area showed $33,639MW/m^2$ on analyzed result. It is important to analyze monthly solar radiation in aspect of maintenance works of solar plant. Monthly solar radiation of May to July was calculated over $160,000W/m^2$ and that of January to February and November to December showed under $80,000W/m^2$ in monthly solar radiation analysis of solar plant area. Also this study compared with solar radiation being calculated from UAV geospatial information and that of National Institute of Meteorological Sciences. And mean solar radiation of study area showed a little high in comparison with whole country data of National Institute of Meteorological Sciences, because the 93.7% of study area was composed of south aspect. Therefore this study can be applied to calculate solar radiation in new developed solar plant area very quickly using UAV.