• Article

    Correlation Analysis between Shading Analysis and Power Output in a Photovoltaic System

    태양광 발전소의 음영 분석과 발전량 상관관계 분석

    Oh Wonwook ・ Jeon Seonggeun ・ Yoon Ayoung ・ Kim Daejang ・ Choi hoonjoo

    오원욱, 전성근, 윤아영, 김대장, 최훈주

    A photovoltaic (PV) string consists of PV modules that are connected in series. When partial shading occurs in the PV modules, the ... + READ MORE
    A photovoltaic (PV) string consists of PV modules that are connected in series. When partial shading occurs in the PV modules, the total PV string current is lowered. When the partial shading becomes severe, the bypass diode operates. Most PV systems are exposed to partial shading by nearby terrain, rather than an actual shaded flat environment. In this study, shading analysis was performed at 19 points of a 33.2 kWp solar power plant installed on the roof of a building, and the shaded irradiance ratio at the PV module location was estimated using this result. We compared the results of the performance ratio monitored for one year. As a result, the expected output ratio of the shading analysis compared to normal was found to be 89.6%, and the annual performance ratio was 90.2%. - COLLAPSE
    April 2021
  • Article

    Agrophotovoltaic Designs : Irradiation Analysis on and under PV Modules

    태양전지 모듈 상부 및 하부 일조량을 고려한 영농형 태양광발전시스템 설계

    Kwon Oh-Hyun ・ Lee Kyung-Soo

    권오현, 이경수

    To secure agricultural benefits and PV power generation from an agrophotovoltaic system, it is vital that the PV modules and the crop ... + READ MORE
    To secure agricultural benefits and PV power generation from an agrophotovoltaic system, it is vital that the PV modules and the crop are both irradiated by light. The configuration and design of PV modules have a practical effect on the irradiation uniformity in an agrophotovoltaic system. Irradiation non-uniformity can cause crop growth delays and quality deterioration during different cultivation periods. This paper proposes the design considerations and parameters of an agrophotovoltaic system to optimize crop yield and power energy production. The design parameters are the PV module installation height, ground coverage ratio, tilt angle, azimuth angle, and PV module installation type. The PV module installation type is classified into dual-axis tracking, single-axis tracking, south fixed, and horizontal fixed. We configured a 3D modeling simulation platform to visualize and analyze irradiation under the PV module. Finally, we suggest three evaluation parameters: The overall mean under PV modules, the overall standard irradiation deviation under PV modules, and the transposition factor of the agrophotovoltaic designs. - COLLAPSE
    April 2021
  • Article

    Operational Result Analysis of 850 kW Photovoltaic System in Eco-friendly Energy Town

    친환경에너지타운 내 850 kW급 태양광발전시스템 운영결과 분석

    Kim Deukwon ・ Heo Jaehyuk ・ Kim Minwhi ・ Lee Dongwon

    김득원, 허재혁, 김민휘, 이동원

    Global climate change demands a change in the social infrastructure, and the transformation of the energy system is indispensable to global trends ... + READ MORE
    Global climate change demands a change in the social infrastructure, and the transformation of the energy system is indispensable to global trends. Jincheon, an eco-friendly energy town located in the innovative city of Chungbuk, is the first renewable energy-based town in Korea. Renewable energy sources, such as photovoltaic, solar thermal, geothermal, and sewage heat are combined to achieve energy sufficiency in the unit area. In this study, the operational results of an 850 kW photovoltaic system, among the renewable energy systems in Jincheon, were analyzed. Based on the operating data from 2018 to 2020, the capacity factor, generation benefit, and CO2 reduction effect were studied. The capacity factor was 14.5%/yr, the generation benefit was 200.6 million won/yr, and the CO2 reduction was 494.7 tons of CO2 eq./yr. Through this study, it was confirmed that Jincheon could serve as a representative example of an eco-friendly energy town during this time of transition of the new energy system. - COLLAPSE
    April 2021
  • Article

    Study on the Wind Pressure Coefficients and Natural Ventilation Performance of Apartment Complexes Considering Wind Direction and Building Layout

    풍향과 동 배치에 따른 아파트 단지의 풍압계수 및 자연환기성능 비교 연구

    Choi Jae-Sol ・ Kim Eui-Jong ・ Yoon Seong-Hoon

    최재솔, 김의종, 윤성훈

    This study aimed to provide basic data and serve as a reference for the planning of natural ventilation in apartment complexes. To ... + READ MORE
    This study aimed to provide basic data and serve as a reference for the planning of natural ventilation in apartment complexes. To analyze the characteristics of the wind pressure coefficients and natural ventilation performance, six cases were selected. The cases were differentiated according to the building layout and height, and CFD (Computational Fluid Dynamics) analysis was conducted under three wind conditions. The results of natural ventilation performance based on wind pressure coefficients showed that a two-line layout provided better ventilation performance than a four-line layout under the same conditions. From the above results, the wind pressure coefficients and ventilation performance can be roughly categorized according to the building arrangement. - COLLAPSE
    April 2021
  • Article

    Operational Result Analysis of Renewable Heat Energy System in Eco-friendly Energy Town

    친환경에너지타운 내 신재생열에너지 시스템 운영결과 분석

    Kim, Deukwon1, Heo, Jaehyuk2, Kim, Minwhi3 and Lee, Dongwon2*

    김득원, 허재혁, 김민휘, 이동원

    The eco-friendly energy town of Jincheon is Korea’s first renewable energy-based energy self-sufficient town that utilizes multiple renewable energy sources, such ... + READ MORE
    The eco-friendly energy town of Jincheon is Korea’s first renewable energy-based energy self-sufficient town that utilizes multiple renewable energy sources, such as PV, solar thermal, geothermal, and sewage heat to achieve power and thermal energy independence in the unit region. In this study, the thermal energy system of Jincheon, which has been operating since 2017, was analyzed. The thermal energy system consists of a seasonal thermal energy storage connected to approximately 1,600 m2 of solar thermal collectors and a midnight thermal energy storage connected to approximately 150 RT heat pumps. Based on data from 2017 to 2020, the heat supply status, expected profits, and greenhouse gas reduction effects of the thermal energy system were analyzed. During the target period, 483 MWh of heating heat, 167 MWh of hot water, and 113 MWh of cooling heat were supplied on an annual average for the last three years. These findings confirmed expected profits of 95.6 million won/yr for hot heat and 1.3 million won/yr for cold heat. In addition, the renewable heat supply resulted in reduction of 156.7 tons of CO2 eq./yr greenhouse gas. - COLLAPSE
    April 2021
  • Article

    Improvement of Structural/Electrical Properties According to ECA Curing Conditions of Direct Bonding Cell

    직접 접합 셀의 ECA 경화조건에 따른 구조적/전기적 특성 개선

    Choi Won Seok ・ Park Jeong Eun ・ Choi Hyuk ・ Lim Donggun

    최원석, 박정은, 최혁, 임동건

    Currently, in the manufacturing of solar modules, there is a limit to large-scale expansion and reduction of raw material usage to reduce ... + READ MORE
    Currently, in the manufacturing of solar modules, there is a limit to large-scale expansion and reduction of raw material usage to reduce module cost. Therefore, research is being conducted to increase the efficiency by changing the module to a shingled structure , rather than increasing the efficiency of the cell unit. In this paper, we analyzed the characteristics of the solar cell by optimizing the bonding cell process of the shingled module structure using an acrylic-based series electrically conductive adhesive (ECA). The experimental conditions were as follows: the curing temperature of the ECA ranged from 130 to 190°C and the curing time ranged from 30 to 180 s. It was confirmed that the efficiency was reduced compared to the existing cutting cell when the curing temperature and curing time ranged from 130 to 150°C and 30 to 60 s, respectively. This is because the lubricating oil component did not decompose owing to the short curing time and low curing temperature. Based on the curing temperature of 170 to 190°C and a curing time of 90 s, the efficiency decreased to less than 0.6%. This is because when the adhesive components of the ECA acrylic-based series are exposed to certain curing conditions, they expand and the silver particles are cracked. A smooth current path was formed when the curing temperature and curing time was 150°C and 150 s, respectively, confirming the highest efficiency of 0.823%. Consequently, for a curing temperature of 150°C and a curing time of 150 s, the lubricating oil components that existed between the silver particles, which are the main components of the ECA, were smoothly decomposed. In addition, through the reduction of the resistance of the ECA and the formation of a smooth current path, a high efficiency of 0.823% was confirmed. - COLLAPSE
    April 2021