• Research Article

    Performance Assessment of Sputter-Coating- Colored BIPV Modules Through Field Test

    현장 실험을 통한 Sputter Coating 컬러 BIPV 모듈의 발전성능 평가

    Lee Hyo-Mun, Yoon Jong-Ho, Kim Hyun-Il, Lee Gun-Hwan

    이효문, 윤종호, 김현일, 이건환

    To assess the performance and characteristics of colored building-integrated photovoltaic (BIPV) modules, a comparative assessment of empirical performance was conducted on colored ... + READ MORE
    To assess the performance and characteristics of colored building-integrated photovoltaic (BIPV) modules, a comparative assessment of empirical performance was conducted on colored BIPV modules (gray, blue, and orange) and general BIPV module. These modules were installed on the south-facing slope (30°) for comparative assessment through a field test. Monitoring data were collected every 10 min from December 20, 2019 to January 21, 2020 and used to performance and characteristics analysis. Performance ratio and module efficiency were utilized during performance indexing for comparative assessment. For general BIPV modules, the operational efficiency was analyzed at 16.63%, whereas for colored BIPV modules, 13.70% (gray), 15.12 % (blue), and 14.49% (orange) were analyzed. It was discovered that the efficiency reduction caused by transmission losses owing to the application of colored cover glasses were 17.74% (gray), 9.05% (blue), and 9.86 % (orange), under field testing conditions. These values turned on an additional 7% reduction in efficiency for gray BIPV modules, compared to the degradation resulting from transmission drop (gray: 10.87%, blue: 8.99%, and orange: 9.02%) calculated using the efficiency of each module in standard test conditions (STC). Performance ratio analysis resulted in the following values: 0.92 for general BIPV modules, and 0.85 (gray), 0.91 (blue), and 0.91 (orange) for colored BIPV modules. As demonstrated by the above results, modules with a colored cover glass may differ in their operational performance depending on their color, unlike general modules. Therefore, in addition to the performance evaluation under STC, additional factors of degradation require consideration through field test. - COLLAPSE
    October 2020
  • Research Article

    Evaluation of UM-LDAPS Prediction Model for Solar Irradiance by using Ground Observation at Fine Temporal Resolution

    고해상도 일사량 관측 자료를 이용한 UM-LDAPS 예보 모형 성능평가

    Kim Chang Ki, Kim Hyun-Goo, Kang Yong-Heack, Kim Jin-Young

    김창기, 김현구, 강용혁, 김진영

    Day ahead forecast is necessary for the electricity market to stabilize the electricity penetration. Numerical weather prediction is usually employed to produce ... + READ MORE
    Day ahead forecast is necessary for the electricity market to stabilize the electricity penetration. Numerical weather prediction is usually employed to produce the solar irradiance as well as electric power forecast for longer than 12 hours forecast horizon. Korea Meteorological Administration operates the UM-LDAPS model to produce the 36 hours forecast of hourly total irradiance 4 times a day. This study interpolates the hourly total irradiance into 15 minute instantaneous irradiance and then compare them with observed solar irradiance at four ground stations at 1 minute resolution. Numerical weather prediction model employed here was produced at 00 UTC or 18 UTC from January to December, 2018. To compare the statistical model for the forecast horizon less than 3 hours, smart persistent model is used as a reference model. Relative root mean square error of 15 minute instantaneous irradiance are averaged over all ground stations as being 18.4% and 19.6% initialized at 18 and 00 UTC, respectively. Numerical weather prediction is better than smart persistent model at 1 hour after simulation began. - COLLAPSE
    October 2020
  • Research Article

    Performance Analysis of CPV Modules for Optimizing Secondary Optical Elements

    CPV모듈의 2차 광학계 특성에 따른 성능분석

    Park Jeom-Ju, Jeong Byeong-Ho, Park Ju-Hoon, Lee Kang-Yeon, Kim Hyo-Jin

    박점주, 정병호, 박주훈, 이강연, 김효진

    Concentrator photovoltaic (CPV) system consists of high-quality complex optical elements, mechanical devices, and electronics components and can have the advantages of high ... + READ MORE
    Concentrator photovoltaic (CPV) system consists of high-quality complex optical elements, mechanical devices, and electronics components and can have the advantages of high integration and high-efficiency energy sources. III-V compound semiconductor cells have proven performance based on high reliability in the aerospace field, but have characteristics that require absolute support of the balance of systems (BOS) such as solar position trackers, receivers with heat sinks, and housing instruments. To determine the optimum parameters of secondary optical elements (SOEs) design for CPV systems, we designed three types of CPV modules, classified as non-SOEs type, reflective mirror type, and CPC lens type. We measured the I-V and P-V characteristics of the prototype CPV modules with the angle of inclination varying from 0° to 12° and with a 500-magnification Fresnel lens. The experimental results assumed misalignment of the solar position tracker or module design of pinpoint accuracy. As a result, at the 0° tilt angle, the CPC lens produced lower power due to the quartz transmittance ratio compared to that by other SOEs. However, for tilt angles greater than 3°, the CPC lens type module achieved high efficiency and stability. This study is expected to help design high-performance CPV systems. - COLLAPSE
    October 2020
  • Research Article

    Determination of the Strength Characteristics of c-Si Solar Cells using Partially Processed Solar Cells

    부분공정 태양전지를 이용한 결정질 태양전지의 강도 특성에 관한 연구

    Choi Su Yeol, Lim Jong Rok

    최수열, 임종록

    Photovoltaic (PV) power system prices have been steadily dropping in recent years due to their mass production and advances in relevant technology ... + READ MORE
    Photovoltaic (PV) power system prices have been steadily dropping in recent years due to their mass production and advances in relevant technology. Crystalline silicon (c-Si wafers) account for the largest share of the price of solar cells; reducing the thickness of these wafers is an essential part of increasing the price competitiveness of PV power systems. However, reducing the thickness of c-Si wafers is challenging; typically, phenomena such as bowing and cracking are encountered. While several approaches to address the bowing phenomenon of the c-Si solar cells exist, the only method to study the crack phenomenon (related to the strength of the c-Si solar cells) is the bending test method. Moreover, studies on determining the strength properties of the solar cells have focused largely on c-Si wafers, while those on the strength properties of front and rear-side electrodes and SiNx, the other components of c-Si solar cells, are scarce. In this study, we analyzed the strength characteristics of each layer of c-Si solar cells. The strength characteristics of the sawing mark direction produced during the production of c-Si wafers were also tested. Experiments were conducted using a 4bending tester for a specially manufactured c-Si solar cell. The results indicate that the back side electrode is the main component that experienced bowing, while the front electrode was the primary component regulating the strength of the c-Si solar cell. - COLLAPSE
    October 2020
  • Research Article

    A Case Study on Energy Consumption and Calibration of Green Remodeling Buildings

    그린리모델링 건물에 대한 에너지소비량 및 보정 사례연구

    Kim Dongil, Lee Byeongho

    김동일, 이병호

    Ministry of Land, Infrastructure and Transport (MOLIT) has increased reduction rate from 18.1% to 32.7% in Building sector compared to ... + READ MORE
    Ministry of Land, Infrastructure and Transport (MOLIT) has increased reduction rate from 18.1% to 32.7% in Building sector compared to BAU of the national greenhouse gas emission according to the 2030 Greenhouse Gas Reduction Road map Amendment. For this purpose, MOLIT has been activating the green remodeling projects for existing buildings. Considering that 15 year old buildings after completion are 74% (5.25 million buildings) among about 7 million existing building stocks in Korea, reduction of building energy consumption by green remodeling is urgently needed, However, it is a major difficulty of activation for green remodeling projects because there are few case studies on Before and After building energy consumption of actual green remodeling projects. Considering that building energy performance and value increase after green remodeling through previous researches, additional studies of the energy consumption assessment on actual green remodeling projects are essential. Therefore, this study aims to propose results on Before and After building energy consumption of actual green remodeling projects. - COLLAPSE
    October 2020