• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 춘계학술대회
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• pp.280-283
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• 2007

The first grid-connected, building-integrated transparent amorphous silicon photovoltaic installation has been operated since October 2004 in Yongin, Korea. The 2.2kWp transparent PV system was applied to the facade of entrance hall in newly constructed KOLON E&C R&D building. The PV module is a nominal 0.98m ${\times}$ 0.95m, 10% transparent, laminated, amorphous(a-Si) thin-film device rated at 44 Wp per module. To demonstrate the architectural features of thin film PV technologies for daylighting application, transparent PV modules are attached to the building envelope with the form of single glazed window and special point glazing(SPG) frames. Besides power generation, the 10% transmittance of a-Si PV module provides very smooth natural daylight to the entrance hall without any special shading devices for whole year. The installation is fully instrumented and is continuously monitored in order to allow the performance assessment of amorphous silicon PV operating at the prevailing conditions. This paper presents measured power performance data from the first 12 months of operation. For the first year, annual average system specific yield was just 486.4kWh/kWp/year which is almost half of typical amorphous silicon PV output under the best angle and orientation. It should be caused by building orientation and self-shading of adjacent mass. Besides annual power output, various statistical analysis was performed to identify the characteristics of transparent thin film PV system.

• 해양환경안전학회지
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• 제18권2호
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• pp.145-152
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• 2012

최근 지구온난화 문제가 대두되면서 신재생에너지 개발을 위한 여러 기술적인 해결책이 제시되고 있는데, 그 중 산업적으로 크게 주목을 받고 있는 분야가 바로 해양에너지이다. 삼면이 바다로 둘러싸인 우리나라는 부존자원이 풍부하여 조력, 조류, 파력에너지에 대한 실용화 기술이 요구되고 있으며, 특히 빠른 조류흐름을 이용하는 조류발전은 해양환경에 거의 영향을 끼치지 않는 친환경적인 발전 방법이다. 조류발전은 조수간만에 의해 발생되는 해수의 자연적인 수평 유체흐름을 로터 및 발전기를 설치하여 회전운동으로 변환시켜 전력을 생산하는 발전 형태이다. 조류발전은 로터의 방향에 따라 크게 수평축 형태와 수직축 형태로 구별할 수 있으며, 발전량은 로터 단면의 크기와 조류속도에 따라 큰차이가 난다. 따라서 본 연구는 저수심형 100 kW급 수평축 조류발전 터빈의 성능해석을 위하여 상용 ANSYS-CFX를 이용하여 3차원 유동해석및 성능평가를 수행하였고, 유동해석을 통해 회전하는 로터 블레이드 표면 유선, 로터 주변 3차원 유동특성에 대해 고찰을 하였다. 그 결과 토크는 터빈의 날개가 증가함에 따라 증가하다가 TSR 3.77에서 최대토크가 발생하였으며, 그 이후 날개끝 속도비가 증가해도 토크는 감소하였다. 또한, 설계유속에서 0.38의 최대 출력계수를 얻었다.

• 한국인터넷방송통신학회논문지
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• 제19권2호
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• pp.187-192
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• 2019

수요관리와 정전에 대한 비상전원 기능을 갖춘 하이브리드 전력저장시스템으로 비상발전설비가 필요한 빌딩 및 공장건축 시에 투자비를 최소화하고, 상시 전력비를 절감함으로서 경제성을 확보할 수 있 기술을 개발함으로써 새로운 비즈니스 모델을 제시한다. 평상시에 STS(Static Transfer Switch)를 통해 부하에 계통 전력을 공급하고 PCS는 계통에 병렬로 연계되어 수요관리를 수행한다. EMS는 수요예측을 통한 전력의 효율적 운용을 위해 ESS에 충방전 지령을 PMS(Power Management System)로 하달하고 PMS는 다시 PCS 제어기로 지령을 전달하여 시스템을 운용한다. 정전시에는 STS가 계통으로부터 빠르게 이탈되면서 PCS는 독립 전원이 되어 부하 측에 정전압/정주파수의 전력을 공급할수 있는 구조이다. 따라서 하이브리드 ESS에 대한 실 계통 연계 및 독립 운전 성능 검증을 통한 신뢰성을 확보할수 있고, 저탄소 녹색성장 기술의 효율적 전력망과 연계 운영이 가능하게 함으로써 ESS 연계를 통한 신재생에너지 발전에 의한 불규칙한 전력 품질개선, 피크부하 기여도 제고가 가능하다. 또한 현재 석탄 화력이 담당하고 있는 주파수추종 예비력을 ESS로 대체함에 따라 연료비가 높은 LNG 발전기 가동비용을 절감할 수 있는 기대효과가 있다.

• 한국철도학회논문집
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• 제17권2호
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• pp.94-99
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• 2014

최근의 신 교통시스템 개발 동향은 주로 지속가능하고 친환경적인 교통수단을 제공하는데 초점이 맞춰져 있다. 그 중에서도, 수요응답형 순환교통(PRT: Personal Rapid Transit) 시스템은 그 가능성 때문에 주목을 받고 있으며, 첨단 전기 자동차(EV) 개발 기술과의 융합을 통해서 경쟁력은 보다 향상되고 있다. 하지만 전기 배터리에 의해 구동되는 차량의 경우 안정적이고 효율적인 운영의 측면에서 기술적인 어려움에 직면하고 있다. 본 논문에서는, 기술적인 난제를 극복하고 전기에너지를 기반으로 한 교통수단의 보급을 증대하기 위하여 태양전지에 의한 보조 전력 공급을 위한 설계적 접근방법에 대해서 모형실험을 통해서 논한다. 그 결과, 실제 차량에 적용했을 시 보조 전원 공급장치로서 일부 서비스 기기에 소요되는 전력량의 대략 11% 정도를 감당할 수 있을 것으로 예측되었다. 특히, 유연소재 태양전지의 장점은 저렴하고 가벼우며 디자인 의도를 최대한 살릴 수 있다는 데 있다. 무엇보다도 유연함과 용이한 부착성은 다양한 분야에서의 확대 적용 가능성을 보여준다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2008년도 춘계학술대회 논문집
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• pp.479-482
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• 2008

Since late of 2000, KIER has developed a novel pyrolysis process for production of fuel oils from polymer wastes. It could have been possible due to large-scale funding of the Resource Recycling R&D Center. The target was to develop an uncatalyzed, continuous and automatic process producing oils that can be used as a fuel for small-scale industrial boilers. The process development has proceeded in three stages bench-scale unit, pilot plant and demonstration plant. As a result, the demonstration plant having capacity of 3,000 tons/year has been constructed and is currently under test operation for optimization of operation conditions. The process consisted of four parts ; feeding system, cracking reactor, refining system and others. Raw materials were pretreated via shredding and classifying to remove minerals, water, etc. There were 3 kind of products, oils(80%), gas(15%), carbonic residue(5%). The main products i.e. oils were gasoline and diesel. The calorific value of gas has been found to be about 18,000kcal/$m^3$ which is similar to petroleum gas and shows that it could be used as a process fuel. Key technologies adopted in the process are 1) Recirculation of feed for rapid melting and enhancement of fluidity for automatic control of system, 2) Tubular reactor specially-designed for heavy heat flux and prevention of coking, 3)Recirculation of heavy fraction for prevention of wax formation, and 4) continuous removal & re-reaction of sludge for high yield of main product (oil) and minimization of residue. The advantages of the process are full automation, continuous operation, no requirement of catalyst, minimization of coking and sludge problems, maximizing the product(fuel oil) yield and purity, low initial investment and operation costs and environment- friendly process. In this presentation, background of pyrolysis technology development, the details of KIER pyrolysis process flow, key technologies and the performances of the process will be discussed in detail.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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• pp.85.1-85.1
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• 2010

$Cu(In,Ga)Se_2$ (CIGS) thin film solar cell is currently 19.5% higher efficiency and developing a large area technology. The structure of CIGS solar cell that make five unit layers as back contact, light absorption, buffer, front transparent conducting electrode and antireflection to make them sequentially forming. Materials and various compositions of thin film unit which also manufacture a variety method used by the physical and chemical method for CIGS solar cell. The construction and performance test of evaporator for CIGS thin film solar cell has been done. The vapor pressures were changed by using vapor flux meter. The vapor pressure were copper (Cu) $2.1{\times}10^{-7}{\sim}3.0{\times}10^{-7}$ Torr, indium (In) $8.0{\times}10^{-7}{\sim}9.0{\times}10^{-7}$ Torr, gallium (Ga) $1.4{\times}10^{-7}{\sim}2.8{\times}10^{-7}$ Torr, and selenium (Se) $2.1{\times}10^{-6}{\sim}3.2{\times}10^{-6}$ Torr, respectively. The characteristics of the CIGS thin film was investigated by using X-ray diffraction (XRD), scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS) and photoluminescence (PL) spectroscopy using a He-Ne laser. In PL spectrum, temperature dependencies of PL spectra were measured at 1137 nm wavelength.

• 한국정보통신학회논문지
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• 제24권8호
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• pp.1058-1063
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• 2020

본 논문에서는 IT 접지 시스템의 감전 및 화재사고 방지를 위한 새로운 절연 저항 계산 기법을 소개한다. 최근 신재생 에너지와 에너지 저장 장치의 확대 보급으로 태양광 발전 시장이 급속하게 성장하고 있으나 절연이 파괴되어 화재사고가 빈번히 발생함에 따라 IT 접지 방식에도 절연 저항 상태를 감시하는 장치가 필수적으로 요구되고 있다. 제안하는 절연 저항 계산 기법은 기존의 고정된 시정수곱 계수기반의 알고리즘에 비해 절연 임피던스의 조건에 따라 동적시정수곱계수를 적용함으로써 넓은 절연 저항 범위에서 빠른 응답 시간과 높은 정확도를 갖는다. 제안하는 동적 시정수 기반 절연 저항 계산 기법은 기존의 방법에 비해 최대 응답 시간은 39.29초, 오차율은 20.11%를 개선시키는 효과를 보였다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 추계학술대회 초록집
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• pp.122.2-122.2
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• 2011

Sulfur hexafluoride ($SF_6$), one of the most potent greenhouse gases, is known as a hydrate former and has been studied at the high pressure up to 1.3 GPa with gas mixtures and with aqueous surfactant. Since we regard $SF_6$ as a potential promoter molecule that can stabilize hydrate structure more effectively compare to the other promoters, further investigation is required to verify the stabilizing ability of $SF_6$ in the hydrate structure. However, the insoluble nature of $SF_6$ in water or gases hinders fine scale analyses. This work discusses the data obtained by using molecular dynamics simulations of structure II (sII) clathrate hydrates containing $SF_6$ and $H_2$. The simulations were performed using the TIP4P/Ice model for water molecule and a previously reported $SF_6$ molecular model (optimized at the pure $SF_6$ single phase system (Olivet and Vega, 2007)), and a $H_2$ molecular model (adapted from the THF+$H_2$ hydrate system (Alavi et al., 2006)). The simulations are performed to observe the stability of $SF_6$ and $H_2$ in the sII clathrate hydrate system with varying temperature and pressure conditions and occupancies of $SF_6$ and $H_2$, which cannot be easily tuned experimentally. We observe that stability of H2 enclathrated in the hydrate structure more affected by the occupancy of $SF_6$ molecules and temperature than pressure, which ranges from 1 to 100 bar.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 추계학술대회 논문집
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• pp.281-284
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• 2007

Recently, we have developed p-i-n a-Si:H single junction thin film solar cells with RF (13.56MHz) plasma enhanced chemical vapor deposition (PECVD) system, and also successfully fabricated the mini modules ($>300cm^2$), using the laser patterning technique to form an integrated series connection. The efficiency of a mini module was 7.4% ($Area=305cm^2$, Isc=0.25A, Voc=14.74V, FF=62%). To fabricate large area modules, it is important to optimise the integrated series connection, without damaging the cell. We have newly installed the laser patterning equipment that consists of two different lasers, $SHG-YVO_4$ (${\lambda}=0.532{\mu}m$) and YAG (${\lambda}=1.064{\mu}m$). The mini-modules are formed through several scribed lines such as pattern-l (front TCO), pattern-2 (PV layers) and pattern-3 (BR/back contact). However, in the case of pattern-3, a high-energy part of laser shot damaged the textured surface of the front TCO, so that the resistance between the each cells decreases due to an incomplete isolation. In this study, the re-deposition of SnOx from the front TCO, Zn (BR layer) and Al (back contact) on the sidewalls of pattern-3 scribed lines was observed. Moreover, re-crystallization of a-Si:H layers due to thermal damage by laser patterning was evaluated. These cause an increase of a leakage current, result in a low efficiency of module. To optimize a-Si:H single junction thin film modules, a laser beam profile was changed, and its effect on isolation of scribed lines is discussed in this paper.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 춘계학술대회 논문집
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• pp.286-286
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• 2009

A small PEM fuel cell has two different stack configurations such as active and passive stacks. The active stack has a distintion of high power density although it makes system complex by using alr blower and related BOPs resulting in large system volume. On the contrary, passive stack has an advantage of compact system because it doesn't need air supplying devices although it reveals relatively low stack power density. In this study we fabricated two 10W PEMFC stacks with different stack configurations, active and passive stacks, and tested their performance and stability. The active stack consists of 13cells with an active area of $5cm^2$. The passive stack has 12cells with an active area of $16cm^2$. When we compared the stack performance of those stacks, the active stack showed higher power density compared to the passive stack, particularly at high voltage regions. However, at low voltage and high current regions, the passive stack performance was comparable to the active stack. The stack stability was largely dependent on the fuel humidity, particularly for active stack. At low humidity conditions, the active stack performance was decreased continuously and the cell voltage distribution was not uniform showing seriously low cell voltage at center cells mainly due to the cell drying. The passive stack showed relatively stable behavior at low humidity and the stack performance was largely dependent on the atmospheric conditions.