1,720,995 research outputs found
A physics based approach for PV lifetime and degradation signatures prediction
No full textPart of this work has received funding from the the Horizon 2020 Research and invention Programme, under Grant Agreement No 952957, Trust-PV project
Assessing the performance, reliability, and economic impact of PV systems installation parameters in harsh climates: Case study
No full textThis study explores the impact of different PV installation parameters on PV modules operating conditions, particularly irradiance levels and module temperature. The study investigates how these variations affect degradation rates and, consequently, the overall lifetime of PV modules. Using a simulation case study in a harsh climate, this paper illustrates the determination of the optimal tilt angle based on factors such as lifetime energy yield, levelized cost of electricity, and greenhouse gas emission factors. It is noteworthy that the chosen location for this study is characterized by significant soiling conditions. The findings underscore the substantial advantages of installing PV modules at relatively higher tilt angles. This strategic choice proves effective in mitigating losses associated with soiling, showcasing an approach that balances optimal energy yield with considerations for prolonged system lifetime and sustainable performance in challenging environments. The research contributes valuable insights for PV designers and stakeholders, emphasizing the need to consider long-term implications and site-pecific challenges when optimizing PV system designs
Analysis and prediction of the performance and reliability of PV modules installed in harsh climates: Case study Iraq
Full text linkThe increasing global demand for renewable energy necessitates a comprehensive understanding of solar photovoltaic (PV) system performance and reliability, particularly in harsh climates such as Iraq. Despite ambitious targets to diversify its energy sector, Iraq faces challenges in the deployment of PV projects due to limited field experience. In this study, we assess the reliability and performance of two different PV systems installed in Basrah and Baghdad, aged 3.5 and 8 years, respectively. Field analysis reveals prevalent issues including glass and cell breakage, delamination, solder bond fatigue, and encapsulant discoloration, contributing to medium degradation rates of 0.91 %/year and 2.6 %/year in Basrah and Baghdad, respectively. Our investigation attributes higher degradation rates not only to ageing but also to suboptimal operation and maintenance (O&M) practices. Additionally, since the two systems are from different manufacturers, we verify that the measured higher degradation rates are mainly attributed to harsh operating conditions rather than differences in manufacturing processes. To extrapolate our findings countrywide, we employ a physics-based model to simulate the degradation rates. Based on the simulated degradation, we proposed four degradation rate zones across the country with degradation rates ranging from 0.62 %/year to 0.96 %/year. By applying these rates to estimate lifetime energy yield across different zones, we demonstrate the trade-offs between higher irradiance zones with reduced PV lifetime and low irradiance zones with longer PV lifetimes. In the study, we compared energy yield simulations using fixed degradation rates with those employing climate-dependent degradation rates. Our analysis revealed that in certain locations in Iraq, employing a fixed degradation rate underestimates the yield by approximately 9.7 %. Conversely, in other locations, it results in overestimations ranging from approximately 10.5 %-31.1 %, highlighting the importance of accurate degradation rate modelling for PV system assessment. Furthermore, we simulate the impact of soiling losses on energy yield, revealing potential losses of up to 70 % depending on location and cleaning schedules. Our findings contribute valuable insights into PV system degradation across harsh climates, addressing critical gaps in global degradation rate data and facilitating more accurate climate-dependent assessments of PV performance and reliability.This study received no funding, and the authors declare no conflict of interest. The authors would like to acknowledge Julian AscencioVasquez ´ for providing processed climatic data used in this study for the mapping. Also, Majid Hamadi Al-Seadi in the Ministry of Oil-Iraq, for the support provided during in the site inspection
A Physics-based Framework for Modelling the Performance and Reliability of BIPV Systems
No full textBuilding-Integrated Photovoltaic (BIPV) systems, operating at elevated temperatures and subject to frequent shading, face unique challenges impacting their performance and reliability. This study presents a comprehensive simulation framework to model and evaluate BIPV system performance and reliability. The framework integrates sub-models for buildings, energy yield, and PV module reliability, validated with experimental data from a BIPV demonstrator. Initially applied to highlight the importance of accurately estimating the micro-climate around the BIPV system, the framework significantly improves modeling accuracy compared to relying solely on ambient climate conditions. The simulation further explores the reliability implications of ventilation in BIPV installations, showing that properly ventilated systems exceed the 25-year module warranty across various climates. Conversely, systems without ventilation experience substantial module lifetime reductions, particularly in hot and dry, and hot and humid climates. The framework is also employed to assess shading impacts on PV module reliability, revealing that while shaded BIPV systems exhibit improved module lifetime, the gains are insufficient to offset energy losses. The proposed framework facilitates diverse "what if" simulations, offering crucial insights into the performance and reliability of BIPV systems for research and project bankability
The Influence of Different Degradation Characteristics on the Greenhouse Gas Emissions of Silicon Photovoltaics: A Threefold Analysis
Full text linkThe environmental footprint of photovoltaic electricity is usually assessed using nominated power or life cycle energy output. If performance degradation is considered, a linear reduction in lifetime energy output is assumed. However, research has shown that the decrease in energy output over time does not necessarily follow a linear degradation pattern but can vary at different points in the module’s lifetime. Further, photovoltaic modules follow different degradation patterns in different climate zones. In this study, we address the influence of different degradation aspects on the greenhouse gas (GHG) emissions of PV electricity. Firstly, we apply different non-linear degradation scenarios to evaluate the GHG emissions and show that the differences in GHG emissions in comparison to a linear degradation can be up to 6.0%. Secondly, we use the ERA5 dataset generated by the ECMWF to calculate location-dependent degradation rates and apply them to estimate the location-specific GHG emissions. Due to the reduction in lifetime energy output, there is a direct correlation between the calculated degradation rate and GHG emissions. Thirdly, we assess the impact of climate change on degradation rates and on the respective GHG emissions of photovoltaic electricity using different climate change scenarios. In a best-case scenario, the GHG emissions are estimated to increase by around 5% until the year 2100 and by around 105% by 2100 for a worst-case scenario
Multi-physics based energy yield modelling of a hybrid concentrated solar power/photovoltaic system with spectral beam splitting
No full textThis work was part of the CSP+ ICON project, funded by VLAIO (Flanders Innovation and Entrepreneurship) , Belgium under project number HBC.2020.2451 and supported by the Flemish spearhead clusters Flux50 and Catalisti
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
A physics-based framework for modelling the performance and reliability of BIPV systems
No full textThis work was supported by the DAPPER project, which is financed by Flux50 and Flanders Innovation & Entrepreneurship, Belgium (project number HBC.2020.2144) . The authors would also like to thank Jens Moschner and Georgi Yordanov of KU Leuven for their support in BIPV setup data acquisition
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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