• Research Article

    Development of a Power Generation Forecast Model that Reflects the Degradation Conditions of Solar Modules: For AI Technique Approach

    태양광 모듈의 열화 조건을 반영한 발전량 예측 모델 개발: AI 기법 접근을 위하여

    Su-Wung Baek, Sung-Gi Kwon, Chang-heon Kim, Gye-Choon Park

    백수웅, 권성기, 김창헌, 박계춘

    This study highlights the significance of solar power as a renewable energy source and addresses the challenge of solar module degradation, which … + READ MORE
    This study highlights the significance of solar power as a renewable energy source and addresses the challenge of solar module degradation, which comprises the accuracy of power-generation forecasts. Traditional forecasting methods depend on facility capacity and average solar irradiance data; however, these methods are prone to intermittency and high uncertainty. In contrast, this study analyzed the degradation of solar modules and proposed an AI-based forecasting model that incorporates these degradation conditions. Indoor and outdoor tests were conducted to measure the I–V characteristics and assess module degradation conditions under various environmental stresses, resulting in the development of a comprehensive database. The study revealed that calculating the annual degradation rate significantly improved forecast accuracy, reducing the average error rate to 0.82%, thereby achieving the research objectives. This research is noteworthy as it enhances forecasting accuracy by introducing a model that accounts for the degradation of solar modules. - COLLAPSE
    PDFXMLCitation
    ReferencesInformation
    30 October 2024

  • Research Article

    On-Site Thermal Performance Evaluation of Flat Plate and Evacuated Tube Solar Collectors

    평판형 및 진공관형 태양열집열기 현장 열성능 평가

    Song Seop Lee, Hee Won Lim, Wang Je Lee, Kyung Ho Lee, U Cheul Shin

    이송섭, 임희원, 이왕제, 이경호, 신우철

    The deployment of solar thermal systems in Korea has predominantly focused on low-temperature applications, such as domestic hot water and space heating. … + READ MORE
    The deployment of solar thermal systems in Korea has predominantly focused on low-temperature applications, such as domestic hot water and space heating. The solar collectors used for these applications are limited to liquid-type flat-plate and evacuated-tube collectors. However, there is a notable absence of domestic performance standards or guidelines for evaluating the thermal performance of these collectors during the design phase of low-temperature solar thermal systems. To address this gap, this study compared the performance of these collectors by analyzing the dynamic behavior and thermal performance characteristics of a solar space heating system in a greenhouse. Both flat-plate and evacuated-tube collectors were used simultaneously in the system. The results are summarized as follows. First, the solar space heating system operated within the low-temperature range throughout the year. Second, incident angle loss, indicating efficiency degradation relative to the certified efficiency of the tube collectors, ranged from 9.5 to 17.0%, during winter and summer, while flat-plate collectors exhibited a higher loss of 26.1 to 31.2%. However, flat-plate collectors exhibited higher average instantaneous efficiency during these periods. Finally, the total annual solar heat gain for the flat-plate collectors was 542.0 kWh/m2, which is approximately 20% higher than the 451.9 kWh/m2 recorded for the evacuated-tube collectors. - COLLAPSE
    PDFXMLCitation
    ReferencesInformation
    30 October 2024

  • Research Article

    A Study on Assessing Supply Chain Vulnerabilities of Solar Photovoltaic Materials and Components

    태양광 설비 소재 및 부품의 공급망 취약성 분석 연구

    Kyung Wan Rho, Byeong In Park, Kyung Yup Kim

    노경완, 박병인, 김경엽

    This study analyzes the supply chain vulnerabilities of materials and components in South Korea’s solar photovoltaic (PV) industry. Using a three-step methodology … + READ MORE
    This study analyzes the supply chain vulnerabilities of materials and components in South Korea’s solar photovoltaic (PV) industry. Using a three-step methodology based on the Trade Specification Index (TSI), Herfindahl-Hirschman index (HHI), and Single-Country Dependency (SCD), we analyzed 17 key intermediate products in the solar PV value chain. The analysis identified significant vulnerabilities in six critical components: wafers, solar cells, silver paste, solar modules, low-iron glass, and other module parts. These components demonstrate high import concentrations and single-country dependency, primarily on China. Our findings highlight the increasing dependency on a single country for essential components since 2017, particularly for wafers, ingots, cells, and modules. This dependency presents potential risks to South Korea's energy security and its transition to renewable energy. To mitigate these vulnerabilities, we propose several policy and industry measures, including expanding domestic production capabilities for wafers, cells, and modules, enhancing R&D investments to improve technological competitiveness; diversifying import sources through strategic international partnerships, and fostering a circular economy through recycling technologies for solar modules. Our study provides valuable insights for policymakers and industry stakeholders to develop strategies to strengthen supply chain resilience and competitiveness in South Korea’s solar PV sector, contributing to the country's energy security in the face of global supply chain disruptions. - COLLAPSE
    PDFXMLCitation
    ReferencesInformation
    30 October 2024

  • Research Article

    Design of Transparent Conductive Oxides with Metal Patterning Techniques

    금속 패터닝 기반 고투과성 산화물 투명전극 설계

    Hyeji Kim, Junghyun Lee, Younggwang Lee, Minwoo Hong, Dohyun Kim, Inpyo Lee, Chanhyuk Choi, Joondong Kim

    김혜지, 이정현, 이영광, 홍민우, 김도현, 이인표, 최찬혁, 김준동

    Transparent electrodes overcome the limitations of opaque electrodes by allowing visible light to pass through, which facilitates their application in various fields … + READ MORE
    Transparent electrodes overcome the limitations of opaque electrodes by allowing visible light to pass through, which facilitates their application in various fields such as transparent photovoltaics, displays, and smart windows. Particularly, transparent electrodes that are more effective in terms of transmittance are useful and structurally flexible. In this study, an efficient approach is proposed for designing transparent conductive oxides with improved transmittance. The oxide/metal/oxide (OMO) structure exhibits outstanding transparency and electrical conductivity. Therefore, a patterned OMO structure was proposed, in which metal oxides and patterned metal layers are deposited. The improvement in the transmittance and the effective resistance by through the patterned structure applied to the metal layer of the OMO structure was confirmed. Patterning the metal layer enabled the superimposition of light absorption, reflection, and scattering effects, which resulted in enhanced optical transparency while maintaining remarkable electrical conductivity. To confirm the transmittance and electrical conductivity of the patterned OMO structure, two types of patterned structures were designed: stripe and hole. These patterned OMO structures exhibit excellent optical transmittances of 73.94% and 74.51%, showcasing an improvement of over 8% compared with the planar OMO structure. Sheet resistance is also significantly affected via pattern designs, reaching 2.15 Ω/□ of striped- pattern and 2.11 Ω/□ of hole-pattern. This suggests that transparent conductive oxides of metal patterning is highly effective to improve the optical and electrical features to be adopted in transparent photovoltaics, energy utilities, and transparent devices. - COLLAPSE
    PDFXMLCitation
    ReferencesInformation
    30 October 2024

  • Research Article

    Predicting Performance of Air Source Heat Pump System with Virtual Refrigeration Cycle

    가상 냉동사이클을 활용한 공기 열원 히트펌프 시스템의 성능 예측

    Shin Heo, Hyo-jun Kim, Jin-hyun Lee, Young-hum Cho

    허신, 김효준, 이진현, 조영흠

    This study aimed to develop and test a performance prediction method using virtual refrigeration cycle generation through the air and indoor-side data … + READ MORE
    This study aimed to develop and test a performance prediction method using virtual refrigeration cycle generation through the air and indoor-side data of a building automation system and heat pumps in an air source heat pump system of a central air-conditioning system, to which the building automation system is applied. The results of coefficient of performance, Δhcomp,ref, Δhcond,ref, and Δhevap,ref of the measured refrigeration cycle according to outside temperature were confirmed. A similar pattern was confirmed by the prediction results through the virtual refrigeration cycle. Reliability evaluation of the performance prediction results of the air source heat pump system was conducted using NMBE and CvRMSE as proposed in ASHRAE guideline 14. NMBE and CvRMSE were confirmed as -6.33% and 15.99% for the coefficient of performance, 0.91% and 11.78% for Δhcond,ref, -5.53% and 12.48% for Δhevap,ref, and 0.14% and 2.85% for Δhcomp,ref, respectively. Thus, the performance of the air heat source heat pump system using a virtual refrigeration cycle can be predicted. Future research will use the performance prediction model of the air heat source heat pump system developed in this study improve the detection and diagnosis of physical and operational failures in heat pump systems. - COLLAPSE
    PDFXMLCitation
    ReferencesInformation
    30 October 2024

  • Research Article

    Study of Test Procedures Requirements for Deriving Values for Building Energy Simulation Parameters

    건물 에너지 시뮬레이션 파라미터 값 도출 시험 절차의 요구 조건에 관한 연구

    Yu-Jin Lee, Hee-Gab Kim, Chan-Yeong Sung, Yu-Bin Lee, Mi-Jung Choi, Dae-Uk Shin

    이유진, 김희갑, 성찬영, 이유빈, 최미정, 신대욱

    Using simulations to evaluate the energy consumption of buildings has advantages in terms of time and cost when compared to testing in … + READ MORE
    Using simulations to evaluate the energy consumption of buildings has advantages in terms of time and cost when compared to testing in actual buildings. However, errors occur between the data from actual buildings with complex parameters and simulation inputs, simplified for more straightforward calculations. Therefore, research is underway to identify the parameters that have the most significant impact on the energy consumption of a building and to compensate for these errors. Therefore, this study has investigated the current status of building energy domestically and internationally to determine the requirements for a parameter value derivation test for building energy simulations. - COLLAPSE
    PDFXMLCitation
    ReferencesInformation
    30 October 2024

  • Research Article

    Optimization-based Modeling of Commercial Buildings with Split System for Energy Simulation

    Split System이 적용된 상업건물의 Energy Simulation을 위한 최적화 기반 모델링 연구

    Jinhyung Park, Kwangwon Choi, Jaewan Joe, Hongjae Cho, Dongkon Hwang

    박진형, 최광원, 조재완, 조홍재, 황동곤

    This study optimized building energy models with HVAC split systems based on actual measurement using EnergyPlus and GenOpt. An eight-story commercial building … + READ MORE
    This study optimized building energy models with HVAC split systems based on actual measurement using EnergyPlus and GenOpt. An eight-story commercial building in Seoul was modeled based on drawings, an energy audit, and measured data. The methodology involved investigating DX split systems, selecting modeling methods, and optimizing based on measured data. Three HVAC systems were examined: the ideal loads air system, VRF, and PTAC. The VRF system was modeled with DesignBuilder and simulated in EnergyPlus. Key parameters included thermal conductivity of walls, doors, windows, internal heat gains, infiltration rates, and coefficients of the HVAC performance curve. The optimized total energy matched the measured data, with NMBE decreasing from 25.30% to 0.40% and RMSE decreasing from 1.15 kWh to 0.84 kWh, meeting ASHRAE Guideline 14. However, although the CV (RMSE) decreased from 51.40% to 37.22%, it still did not meet ASHRAE Guideline 14. This study demonstrates the feasibility of using GenOpt to optimize building energy models with HVAC systems in EnergyPlus, which can be used for various research purposes. - COLLAPSE
    PDFXMLCitation
    ReferencesInformation
    30 October 2024

  • Research Article

    Analysis of Energy-Saving Effects According to Green-Remodeling Technology Elements in Apartment and Single-family House

    그린리모델링 기술요소 적용에 따른 단독 및 공동주택의 에너지 저감 효과 분석

    Subin Jeong, Jinhee Kim, Juntae Kim

    정수빈, 김진희, 김준태

    Green remodeling has been proposed as a carbon-reduction methodology for existing buildings in Korea. Notably, residential buildings account for 46% of the … + READ MORE
    Green remodeling has been proposed as a carbon-reduction methodology for existing buildings in Korea. Notably, residential buildings account for 46% of the total existing buildings in Korea. Among these, residential buildings older than 15 years account for approximately 67%; therefore, green remodeling is essential for reducing greenhouse gas emissions. However, previous research has been limited to analyzing the energy performance of green remodeling technology elements in residential buildings. Therefore, the present study examined the energy performance of old housing models based on the elapsed age of apartments and single-family houses through the application of green remodeling elements. Applying photovoltaic power generation facilities is the most advantageous method to reduce primary energy consumption in the lifetimes of both apartments and single-family houses, and the shorter the elapsed life, the greater the energy-saving rate. Building Attached Photovoltaic (BAPV) system elements were the most advantageous for energy savings in all elapsed years. Specifically, the maximum reduction in primary energy consumption was 22.3% for apartments and 30.8% for single-family houses. In addition to the technological elements of new and renewable energy, the application of passive design is advantageous for energy saving in both single-family and multi-family houses, and the shorter the elapsed life, the more beneficial the application of active design is for energy saving. - COLLAPSE
    PDFXMLCitation
    ReferencesInformation
    30 October 2024
리스트형 보기썸네일형 보기
Journal Informaiton Journal of the Korean Solar Energy Society Journal of the Korean Solar Energy Society
Online Submission
  • NRF
  • KOFST
  • crossref crossmark
  • crossref cited-by
  • crosscheck
  • orcid
  • open access
  • ccl
Journal Informaiton Journal Informaiton - close