• 동굴
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• 제95호
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• pp.15-21
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• 2009

온실가스와 지구촌 온난화, 그리고 이를 치유하기 위한 인간의 노력과 필요한 대안기술은 마치 성난 자연을 잠재우기 위한 노력과 그에 필요한 재원을 동원하기보다도 더 어려운 일인가보다. 한정된 화석연료는 수십 년 내에 고갈될 수밖에 없으며, 국제무대에서 나라마다 자원을 확보하려는 외교활동의 치열함은 마치 자원 확보를 위한 전쟁을 방불케 하는 모습이다. 화석연료의 고갈은 친환경 녹색성장이라는 새로운 대안정책을 불러왔고, 태양에너지 활용을 위한 태양전지기술은 날로 발전을 거듭하고 있으며, 이와 함께 세상을 밝혀주기 위한 조명광기술은 석유등, 백열등으로부터 발광다이오드에 이르러 첨단 광역시장을 이루었다. 따라서 이들을 탄생시킨 반도체기술로부터 태양전지와 발광다이오드를 접목시켜 일체화시킨 SOLAR-LED 시스템과 함께 저탄소녹색조명의 동굴응용 기술을 조명한다.

• 전기화학회지
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• 제20권1호
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• pp.18-25
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• 2017

본 총설에서는 최근 전세계적으로 각광 받고 있는 유기 금속 할라이드 페로브스카이트 소재에 기반한 태양광 물분해 연구에 대해 정리하였다. 크게, 현재까지 연구보고들을 태양전지-전기분해기 구성 (photovoltaic-electrolyzer configuration) 및 통합 태양광 물분해 (integrated photoelectrolysis)로 분류하여 최근 연구결과들을 소개하였다. 해당 분야 연구는 아직 초기 단계에 있으며, 향후 효과적인 보호막 개발, 고전압 텐덤전지 제작 등이 필요함을 보였다.

• Journal of Power Electronics
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• 제2권1호
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• pp.11-18
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• 2002

The development of the solar and the wind energy is necessary since the future alternative energies that have no pollution and no limitation are restricted. Currently MW Class power generation system has been developed, but it still has a few faults with the weather condition. In order to solve these existing problems, combined generation system of photovoltaic and wind power was suggested. It combines wind power energy and solar energy to have the supporting effect from each other. However, since even combined generation system cannot always generate stable output with everchanging weather condition, power storage apparatus that uses elastic energy of spiral spring to combined generation system was also added for the present study.

• 한국산업융합학회 논문집
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• 제22권4호
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• pp.395-403
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• 2019

The excessive need of power is creating an unbalance situation in power sector, where solar energy is one of the best solutions among other energy sources to mitigate this demand. It is globally accepted because of its flexibility and long life compared to others. A lot research is going on to enhance the energy efficiency by introducing photovoltaic (PV) power generation technology, but still irradiation of PV power is the major problem. In this manuscript, we have designed PV module using single diode methodology and also the solar conversion efficiency was boosted with maximum power point tracking (MPPT) by using perturb and observe (P&O) algorithm. The simulation was done for $1000W/m^2$ and $800W/m^2$ at solar irradiance in cell temperature of 25C and 40C degree levels in PSIM tool.

• 천문학회보
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• 제45권1호
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• pp.44.1-44.1
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• 2020

Hα jets of cool chromospheric plasma are protruding into the solar corona 10-100 Mm above the photosphere. The driving mechanisms of Hα jets have been widely studied for decades. However, the detailed process is still elusive. We observed shock signatures moving along a dark jet using 1.6 meter Goode Solar Telescope at Big Bear Solar Observatory. The first shock front of the jet shows sharp --- when it moves upward, while fuzzy and granulated when it moves downward. The jet itself extends upward when the second shock front of the jet reaches the top of the jet. We find abrupt EUV brightenings when the second shock front collides with the edge of the jet. The third front and the fouth front quasi-periodically. These phenomena might be the signs of the rebound shock waves triggered by p-mode wave leakages at the bottom of the jets. Our observation suggests that the jet can be triggered by the rebound shock waves generated by the p-mode waves leaked at the bottom of the jets.

• Advances in Energy Research
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• 제5권3호
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• pp.227-237
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• 2017

The continuous increase of emission rates of green house gases and the effects on global warming added a new dimension to the problem of substituting the petroleum and its derivatives by environment friendly and sustainable energy sources for the world. Solar and wind energy appear at the top of the list of renewable of high potential, widely available, of dominated technology and well accepted. Brazil is one of the few countries in the world that receives number hours of sunshine exceeding 3,000 hours per year with a daily average of 4.5 to 6 kWh. However, this potential is largely unexplored and poorly tapped. The number of renewable systems implanted in Brazil has grown in recent years, but still insignificant when compared, for example, with Germany and Spain among others. This paper presents the results of an optical study on small concentration solar collector with evacuated tube enveloping the absorber and internal reflective surface fixed on the bottom part of the evacuated tube. The designed collector has a 2D geometrical concentration ratio between 2.455 and 4.91. The orientation of the solar collector, the ratio of the radius of the receiver to the radius of the absorber, the incidence angle for each period of the year, the collector inclination angle, the aperture angle of the reflective surface, concentration and optical efficiency were determined. The ray traces and flux distribution on the absorber of the evacuated tube solar collector were determined by using the program Ray Optics Simulation. The optical efficiency varies during the year according to the solar declination. For the periods were the solar declination is close to zero the efficiencies are maximum, and the variation during the day is around 25.88% and 99.9%. For the periods were the solar declination is maximum the efficiencies are minimum, and the variation during the day is around 23.78% and 91.79%.

• 대한기계학회논문집A
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• 제34권12호
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• pp.1837-1842
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• 2010

화석에너지의 고갈로 인한 대체 에너지 연구는 최근 수십 년 동안 계속 행해지고 있다. 원자력 에너지와 비교해서 낮은 전기발생 효율에도 불구하고, 환경친화적이며 태양이라는 영구성으로 태양에너지는 주목 받고 있다. 본 논문에서는 태양전지의 효율에 가장 영향을 미치는 인자로 햇빛 입사각의 변화와 Top Connector 형상이라 가정하고 MATLAB 과 MathCAD 를 이용하여 모사하였다. 실험모사 결과 상용화 제품인 500um 선폭, 5um 높이 Top Connector 형상과 비교하여, 최고 10%의 태양전지 효율증가는 Top Connector 후막 두께가 25~50 um, 선폭 두께가 50~100um 영역에서 찾을 수 있었다. 10 만 cps 의 점도를 갖는 은페이스를 500um 의 MDDW (Micro-Dispensing Deposition Writing) 직접분사 노즐을 이용하여 성공적으로 25 um 후막을 형성하였다.

• 에너지공학
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• 제21권4호
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• pp.356-361
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• 2012

지열, 풍력, 태양열에너지 등과 같은 신재생에너지 분야에 관한 연구가 활발히 이루어지고 있으나 전체 에너지 중에서 차지하는 비율은 아직 미미하다. 본 논문은 주열원인 열사이폰관형 태양열집열기와 보조열원인 X-L 파이프 보일러장치를 서로 결합한 하이브리드 난방시스템에 관한 연구이다. 특히 새로운 형태의 열사이폰관형 태양열집열기에 관한 성능 평가와 함께 보조열원장치의 성능 및 안전성에 대해 조사하였다. 그 결과, 열사이폰관형 태양열집열기는 이중관형 태양열집열기보다 집열효율이 그 구조적 특성 때문에 최대 20.7% 더 증가하였다. 또한 보조열원장치의 X-L 파이프 내 특수열매체는 순수 물보다 약 20% 더 빠르게 온도가 상승하였으며, X-L 파이프 보일러는 안정성 때문에 팽창압력 해소장치가 필요함을 확인하였다.

• Environmental Engineering Research
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• 제12권5호
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• pp.238-243
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• 2007

The Fenton reaction, which refers to the reaction between ferrous ions and hydrogen peroxide to produce the OH radical, has not been widely applied to the disinfection of microorganisms despite being economic and environmentally friendly. Cho et al. have previously proposed the neutral photo ferrioxalate system as a solution to the problems posed by the Fenton reaction in acidic conditions, but this system still requires an external hydrogen peroxide supply. In the present study, we developed a simple disinfection technology using the photo or solar ferrioxalate reaction without the need for an external hydrogen peroxide supply. E. coli was employed as the indicating microorganism. The study results demonstrated the effectiveness of the photo ferrioxalate system in inactivating E. coli without any external hydrogen peroxide supply, as long as dissolved oxygen is supplied. Furthermore, the solar ferrioxalate system achieved faster inactivation of E. coli than an artificial light source at similar irradiance.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.420.1-420.1
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• 2016

Colloidal quantum dot (CQD) is emerging as a promising active material for next-generation solar cell applications because of its inexpensive and solution-processable characteristics as well as unique properties such as a tunable band-gap due to the quantum-size effect and multiple exciton generation. However, the most widely used spin-coating method for the formation of the quantum dot (QD) active layers is generally hard to be adopted for high productivity and large-area process. Instead, the spray-coating technique may potentially be utilized for high-throughput production of the CQD solar cells (CQDSCs) because it can be adapted to continuous process and large-area deposition on various substrates although the cell efficiency is still lower than that of the devices fabricated with spin-coating method. In this work, we observed that the subsequent treatment of two different ligands, halide ion and butanedithiol, on the lead sulfide (PbS) QD layer significantly enhanced the cell efficiency of the spray CQDSCs. The maximum power conversion efficiency was 5.3%, comparable to that of the spin-coating CQDSCs.