• Research Article

    A Comparison Analysis on the Efficiency of Solar Cells of Shingled Structure with Various ECA Materials

    다양한 ECA 소재를 활용한 shingled 구조의 태양전지 효율 비교 분석

    Jang Jae Joon, Park Jeong Eun, Kim Dong Sik, Choi Won Seok, Lim Donggun

    장재준, 박정은, 김동식, 최원석, 임동건

    Modules using 6 inch cells have problems with loss due to empty space between cells. To solve this problem made by shingled ... + READ MORE
    Modules using 6 inch cells have problems with loss due to empty space between cells. To solve this problem made by shingled structure which can generate more power by utilizing empty space by increasing the voltage level than modules made in 6inch cell. Thus, in this paper, the c-Si cutting cells were produced using nanosecond green laser, and then the ECA was sprayed and cured to perform cutting cell bonding. Three types of ECA materials (B1, B2, B3) with Ag as the main component were used, and experimental conditions varied from 5 to 120 seconds of curing time, 130 to 210°C of curing temperature, and 1 to 3 of curing numbers. As a results of experiments varying curing time, B1 showed efficiency 19.88% in condition of 60 seconds, B2 showed efficiency 20.15% in 90 seconds, and B3 showed efficiency 20.27% in 60 seconds. In addition, experiments with varying curing temperature, It was confirmed highest efficiency that 20.04% in condition of 170°C with B1, 20.15% in condition of 150°C with B2, 20.27% in condition of 150°C with B3. These are because the Ag particles are densely formed on the surface to make the conduction path. After optimizing the conditions of temperature and curing time, the secondary-tertiary curing experiments were carried out. as the structural analysis, conditions of secondary-tertiary curing showed cracks that due to damp heat aging. As a result, it was found that the ECA B3 had the highest efficiency of 20.27% in condition of 60 seconds of curing time, 150°C of curing temperature, and single number of curing, and that it was suitable for the manufacture of Solar cell of shingled structure rather than ECA B1 and B2 materials. - COLLAPSE
    August 2019
  • Research Article

    Beam and Diffuse to Global Solar Irradiation Correlation Coefficients for Daejeon

    대전지역 직달 및 산란과 전일사 상관계수

    Lee Kwan-Ho, Song Doo-Sam

    이관호, 송두삼

    The total solar irradiation on horizontal surfaces is separated into the beam and diffuses components. Although horizontal global irradiance is a commonly ... + READ MORE
    The total solar irradiation on horizontal surfaces is separated into the beam and diffuses components. Although horizontal global irradiance is a commonly measured parameter for many sites, horizontal diffuse irradiance is not so readily obtainable. For such sites that measure global irradiation alone, a simple but reasonably accurate method is required to estimate diffuse irradiance from its global counterpart. This study investigates the applicability of correlation coefficients models correlating hourly diffuse and beam fraction and hourly clearness index in Daejeon. The three diffuse to global correlation coefficients models (Orgill and Holland model, CIBSE Guide J model, and Erbs et al. model) are selected and the three modified beam to global correlation coefficients models are generated. MBE, RMSE, r-squared of Daejeon and Daejeon boundary site-fitted models are compared with the case of original coefficients. The comparison result shows that the beam and diffuse to global solar irradiation correlation coefficients models with boundary site-fitted coefficients are best suitable for Daejeon. Further researches will be conducted to find the boundary site-fitting method using measured data of other cities and correlation coefficients models using solar altitude, cloud cover, and sunshine duration. - COLLAPSE
    August 2019
  • Research Article

    Recent Progress and Prospect of Luminescent Solar Concentrator

    발광형 태양광 집광기 최신 연구 동향

    송형준

    Song Hyung-Jun

    Luminescent solar concentrator (LSC), consisting of luminophore included glass or substrate with edge-mounted photovoltaic cell, is semi-transparent, energy harvesting devices. The luminophore ... + READ MORE
    Luminescent solar concentrator (LSC), consisting of luminophore included glass or substrate with edge-mounted photovoltaic cell, is semi-transparent, energy harvesting devices. The luminophore absorbs incident solar light and re-emit photons, while the waveguide plate allows re-emitted photons to reach edge or bottom mounted photovoltaic cells with reduced losses. If the area of LSC is much larger than that of photovoltaic cell, this system can effectively concentrate solar light. In order to improve the performance of LSC, new materials and optical structures have been suggested by many research groups. For decreasing re-abosprion losses, it is essential to minimize the overlap between absorption and photoluminescence solar spectrum of luminophoroe. Moreover, the combination of selective top reflector and reflective optical cavity structure significantly boosts the waveguide efficiency in the LSC. As a result of many efforts, commercially available LSCs have been demonstrated and verified in the outdoor. Also, it is expected to generate electricity in buildings by replacing conventional glass to LSCs. - COLLAPSE
    August 2019
  • Research Article

    Trend Review of Solar Energy Forecasting Technique

    태양에너지 예보기술 동향분석

    Cheon Jae ho, Lee Jung-Tae, Kim Hyun-Goo, Kang Yong-Heack, Yun Chang-Yeol, Kim Chang Ki, Kim Bo-Young, Kim Jin-Young, Park Yu Yeon, Kim Tae Hyun, Jo Ha Na

    전재호, 이정태, 김현구, 강용혁, 윤창열, 김창기, 김보영, 김진영, 박유연, 김태현, 조하나

    The proportion of solar photovoltaic power generation has steadily increased in the power trade market. Solar energy forecast is highly important for ... + READ MORE
    The proportion of solar photovoltaic power generation has steadily increased in the power trade market. Solar energy forecast is highly important for the stable trade of volatile solar energy in the existing power trade market, and it is necessary to identify accurately any forecast error according to the forecast lead time. This paper analyzes the latest study trend in solar energy forecast overseas and presents a consistent comparative assessment by adopting a single statistical variable (nRMSE) for forecast errors according to lead time and forecast technology. - COLLAPSE
    August 2019
  • Research Article

    A Study on the Effect of Particulate Matter Concentration on the Reliability of Decomposition Model

    미세먼지 농도가 직산분리 모델의 신뢰성에 미치는 영향에 관한 연구

    Lee Sang-Hyuk, Lee Kyung-Soo

    이상혁, 이경수

    Recently, as the amount of particulate matter blowing from China increases, the domestic air environment is rapidly deteriorating. This pollution of the ... + READ MORE
    Recently, as the amount of particulate matter blowing from China increases, the domestic air environment is rapidly deteriorating. This pollution of the atmosphere greatly affects the light energy reaching the ground. Particularly, since the light enters the solar cell module in various forms, the amount of input energy of the solar power generation system may be changed depending on the ratio of direct beam irradiation and diffused horizontal irradiation. In this paper, we analyze how the ratio of direct beam component and diffused component on global horizontal irradiation varies with the atmospheric conditions. In addition, the reliability of the regression equation, designed to decompose the global horizontal irradiation into horizontal direct beam irradiation and diffused horizontal irradiation, was verified according to the level of air pollution. So, we derive the most suitable decomposition model for use in domestic climatic conditions in Korea by comparing the ratio of direct and diffuse component on the horizontal which is calculated with Perez model and Watanabe model using the meteorological weather data observed for 14 months. Finally, to reduce the error of the transposition result, we verified the reliability of the decomposition which depends on the atmospheric environment. - COLLAPSE
    August 2019
  • Research Article

    Analysis of the Effect of the Grid-connected Photovoltaic System in Fault Case of Power System

    전력계통 고장시 계통연계형 태양광발전시스템의 영향분석

    Park Sung-Hun*, Lee Yong-Sik, Jeong Sung-Won, Gim Jae-Hyeon

    박성훈, 이용식, 정성원, 김재현

    Among the main functions of the grid-connected photovoltaic (PV) system, the anti-islanding operation function is a very important problem. Recently, due to ... + READ MORE
    Among the main functions of the grid-connected photovoltaic (PV) system, the anti-islanding operation function is a very important problem. Recently, due to the improvement in power generation efficiency and the maintenance advantages in PV system, the use of string inverter has increased so that the possibility of islanding operation has been raised. Generally, when a power system faults, the PV inverter must be disconnected from power system within 10 cycles by the anti-islanding operation function. However, in the real-time of power system, the output power of the PV system within 10cycles is effected. In this paper, we analyzed the effect of grid-connected PV system on power quality in a short time within 10 cycles on fault case of power system using the Matlab Simulink program. - COLLAPSE
    August 2019
  • Research Article

    Analysis of Capacity Factors and Capacity Credits for Wind Turbines Installed in Korea

    국내 풍력발전 설비의 이용률과 용량크레딧 분석

    Paik Chunhyun

    백천현

    The capacity credit (CC) is a key metric for mid- to long-term power system capacity planning. The purpose of this study is ... + READ MORE
    The capacity credit (CC) is a key metric for mid- to long-term power system capacity planning. The purpose of this study is to estimate the CCs of domestic wind turbines. Based on hourly capacity factor (CF) data during the seven years from 2011 to 2017, the new so-called probabilistic CF scheme is introduced to effectively reflect the variability of CFs on CC estimation. The CCs are then estimated through the CF-based method and the ELCC (Effective Load Carrying Capability) method reflecting the probabilistic CF scheme, and the results are compared. The results show that the CC value 0.019 for domestic wind turbines proposed in the 8th Basic Plan for Electricity Supply and Demand corresponds to the CC with a confidence level slightly lower than 95%. - COLLAPSE
    August 2019