1,720,964 research outputs found
Benchmarking yield assessment exercise in different climates within an international collaboration framework
No full textEnergy yield framework to simulate thin film CIGS solar cells and analyze limitations of the technology
No full textAbstract This study presents a comprehensive evaluation of Copper Indium Gallium Selenide (CIGS) solar technology, benchmarked against crystalline silicon (c-Si) PERC PV technology. Utilizing a newly developed energy yield model, we analyzed the performance of CIGS in various environmental scenarios, emphasizing its behavior in low-light conditions and under different temperature regimes. The model demonstrated high accuracy with improved error metrics of normalized mean bias error (nMBE) ~ 1% and normalized root mean square error (nRMSE) of ~ 8%–20% in simulating rack mounted setup and integrated PV systems. Key findings reveal that the CIGS technology, while slightly underperforming in integrated, low-irradiance setups, shows comparable or superior performance to c-Si PERC technology in high-irradiance and high-temperature conditions. A significant focus of the study was on the low-light performance of CIGS, where it exhibited notable voltage losses. Our research highlights the importance of reducing the diode ideality factor for enhancing CIGS power conversion efficiency, particularly In low-light conditions. These insights provide a pathway for future research and technological improvements, emphasizing defect engineering, passivation strategies to advance the understanding and application of the CIGS technology
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
Physics-based electrical modelling of CIGS thin-film photovoltaic modules for system-level energy yield simulations
Full text linksponsorship: The work is supported by the Kuwait Foundation for the Advancement of Sciences (KFAS) under project number CN18-15EE-01 and by Flanders Innovation & Entrepreneurship and Flux50 under project DAPPER, HBC.2020.2144. (Kuwait Foundation for the Advancement of Sciences (KFAS)|CN18-15EE-01, Flanders Innovation & Entrepreneurship|HBC.2020.2144)status: Publishe
Geography based bi-facial cell design for low LCoE
No full textThe Levelized Cost of Electricity (LCoE) produced by PV systems is determined by yield (kWh) and cost of the system. Reducing the LCoE of the solar power can be achieved either by increasing the yield or by reducing the cost. The yield of bi-facial PV systems is promoted by high efficiency and a high bi-faciality factor.Yield due to the front efficiency depends on the parameters ( , and ) that contribute to that efficiency. It was found that the different parameter helped maximize the yield in each climatic condition. For low irradiation and low operating temperature zones, yield improved when the product was increased at the cost of the . While at equatorial tropical climates with fairly high temperatures, yiele improved when was increased at cost of and . For high irradiance and high temperature desert climates, yield improved when the product increased at the cost of . Designing cells to suit the operating conditions of the region improved yield per thereby reducing the LCoE.A large part of the cell processing cost is in the metal (silver) used on the cell. The amount of silver is usually optimized for the cell efficiency (i.e. power in W) delivered under standard test conditions, i.e. a solar irradiance of 1000 W/m2. When the metal patterns were optimized for the yield at a climatic zone, results showed that up to 50\% of silver per cell could be saved (From a reference cell considered). Up to 5\% LCoE improvement was theorized. The irradiance on the bi-facial modules varies with different system orientations (Equator facing, East west tilted, East West Vertical ). The metal patterns were also optimized for the different system orientation at a climatic condition. The results showed metal patterns can be made more thin when designed for vertical systems.Advanced c-Si cell concepts try to reach the theoretical efficiency by employing different passivation technologies, grid patterns, etc. Each cell technology will have advantage over the other. This makes it interesting to study if we can attribute a cell concept to a climatic condition where it will outperform other cell concepts
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
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
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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
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