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AbstractThis study presents the results obtained from simulated performance monitoring of seven different roof mounted PV systems in Abu Dhabi, the largest of UAE's emirate. Data were analyzed to evaluate the suitability of PV systems for installations in different types of buildings in the UAE. The PV systems consisted of amorphous silicon (a-Si) and polycrystalline silicon (p-Si) PV technologies. Different performance evaluation parameters are presented. The results give an indication of the system performance and provide a basis for economic and environmental assessment of the PV generated electricity.

Due to the single-phase loads and their stochastic behavior, the current in the distribution feeders is not balanced. In addition, the single-phase loads are located in different positions along the LV feeders. So the amount of the unbalanced load and its location affect the feeder losses. An unbalanced load causes the feeder losses and the voltage drop. Because of time-varying behavior of the single-phase loads, phase balancing is a dynamic and combinatorial problem. In this research, a heuristic and dynamic solution for the phase balancing of the LV feeders is proposed. In this method, it is supposed that the loads’ tie could be connected to all phases through a three-phase switch. The aim of the proposed method is to make the feeder conditions as balanced as possible. The amount and the location of single-phase loads are considered in the proposed phase balancing method. Since the proposed method needs no communication interface or no remote controller, it is inexpensive, simple, practical, and robust. Applying this method provides a distributed and dynamic phase balancing control. In addition, the feasibility of reducing the used switches is investigated. The ability of the proposed method in the phase balancing of the LV feeders is approved by carrying out some simulations.

The accelerator-driven sub-critical system is driven by external neutron sources, which are generated by the spallation reaction and maintain the stable operation of the sub-critical core, while the external neutron source increases the complexity of reactor neutron kinetic processes. This article focuses on simulation analysis of neutron space–time kinetics with a dynamic analysis code, which is developed based on the improved quasi-static approximation and Monte Carlo neutron transport method. The amplitude function and shape functions are solved to achieve the dynamics simulation process. Then, the transient responses of beam interruptions and reactivity insertions are calculated and analyzed for an experimental facility. To further verify the correctness and reliability of dynamic behavior, the simulation results are compared with experimental values, and the results show that the normalized neutron fluxes varying with time are in good agreement with the corresponding values. It can be concluded that the improved quasi-static coupled probability theory method can be used to solve the neutron space–time kinetic problem of the experimental facility, and the results are reliable.

Abstract This study investigates the viability of novel green solvents for carbon capture. Three different types of amine based deep eutectic solvents were synthesized at three different molar ratio. The selected amines represent the primary (monoethanolamine), secondary (diethanolamine) and tertiary (methyldiethanolamine) amines, respectively. The CO 2 absorption was conducted with a solvent screening set-up (SSS) and the CO 2 loading was measured with an ‘Elementar’ total organic carbon (TOC) analyzer. Thereafter, FTIR of the samples was conducted in order to determine the qualitative analysis for tracking the appearance, disappearance and stability of different functional groups (400-1600 cm-1). The solubility experiments were performed based on the conditions of the absorber in the post-combustion capture process (P CO2 = 15kPa and T = 40 o C). Results revealed that amine-based DESs have absorption capacity that is much higher than both 30wt% aqueous amine solutions and conventional DESs. The FTIR broadening of the O–H and N–H stretching of MEA and ChCl individual components, indicates the formation of hydrogen bonds between the two of them in the ChCl-MEA 1:6 before CO2 absorption.

Water canal networks that are widely used for irrigation are an equally good source of micropower generation to be fed to the nearby areas. A practical example of such a system is the micro-hydro generation at Renala Khurd Pakistan integrated with the national grid known as hydro–grid configuration. Apart from the rare Renala Khurd hydro generation example, solar photovoltaic generation integrated with a mainstream network, i.e., solar PV-Grid configuration, is widely used. The integrated operation of combinations of primary distributed generation sources has different operational attributes in terms of economics and reliability that are needed to be quantified before installation. So far, various combinations of primary distributed generation sources have been simulated and their accumulative impact on project economics and reliability have been reported. A detailed economic and reliability assessment of various configurations is needed for sustainable and cost-effective configuration selection. This study proposes a trigeneration combination of solar–hydro–grid with an optimal sizing scheme to reduce the solar system sizing and grid operational cost. A genetic algorithm based optimal sizing formulation is developed using fixed hydro and variable solar and grid systems with a number of pre-defined constraints. The hydro–grid, solar–grid, and grid–hydro–solar configurations are simulated in HOMER Pro software to analyze the economic impact, and to undertake reliability assessments under various configurations of the project. Finally, optimal values of the genetic algorithm are provided to the HOMER Pro software search space for simulating the grid–hydro–solar configuration. It was revealed that the net present cost (NPC) of hydro-to-grid configuration was 23% lower than the grid–hydro–solar configuration, whereas the NPC of grid–hydro–solar without optimal sizing was 40% lower than the solar–grid configuration, and the NPC of grid–solar–hydro with the genetic algorithm was 36% lower than the hydro–grid configuration, 50.90% lower than solar–grid–hydro without the genetic algorithm, and 17.1% lower than the grid–solar configuration, thus proving utilization of trigeneration sources integration to be a feasible solution for areas where canal hydropower is available.

The influence of the transparent conducting oxide (TCO) topography was studied on the performance of a silicon oxide intermediate reflector layer (IRL) in a-Si/μc-Si tandem cells, both experimentally and by 3-D optical simulations. Therefore, cells with varying IRL thickness were deposited on three different types of TCOs. Clear differences were observed regarding the performance of the IRL as well as its ideal thickness, both experimentally and in the simulations. Optical modeling suggests that a small autocorrelation length is essential for a good performance. Design rules for both the TCO topography and the IRL thickness can be derived from this interplay.

Una de las tareas importantes para aumentar la eficiencia del sistema fotovoltaico (PV) es el desarrollo y la mejora de los algoritmos de seguimiento del punto de máxima potencia (MPPT). Estos algoritmos MPPT conducen a la capacidad de capturar de manera eficiente el punto de máxima potencia global de la matriz fotovoltaica parcialmente sombreada. Uno de estos rastreadores es el algoritmo de optimización de enjambre de partículas (PSO), que es una de las técnicas de computación blanda. Los rastreadores convencionales basados en PSO tienen muchas ventajas, como la simplicidad de la implementación de hardware y la independencia del sistema instalado. El problema real de la aplicación práctica del PSO es la determinación de sus parámetros para garantizar una alta efectividad de la extracción del MPP global. El análisis de los trabajos científicos dedicados al algoritmo PSO ha demostrado que actualmente no existe una metodología para la selección de los parámetros óptimos de los seguidores de máxima potencia basados en el algoritmo PSO para el sistema fotovoltaico. Este trabajo tiene como objetivo crear un método conveniente y razonable para elegir los parámetros óptimos del algoritmo PSO, teniendo en cuenta la topología y los parámetros del convertidor DC-DC y la configuración de los paneles solares. Se ha presentado un nuevo método para seleccionar los parámetros de un convertidor reductor conectado a una batería. El valor óptimo del tiempo de muestreo para los controladores digitales MPP, proporcionando su máximo rendimiento; se ha determinado en base a una nueva metodología. El paquete de software Matlab/Simulink se utiliza como la principal herramienta de investigación. Los resultados destacados identifican que el PSO modificado y sus parámetros diseñados cumplen mejor con los requisitos del controlador MPPT para el sistema fotovoltaico. L'une des tâches importantes pour augmenter l'efficacité du système photovoltaïque (PV) est le développement et l'amélioration des algorithmes de suivi du point de puissance maximale (MPPT). Ces algorithmes MPPT permettent de capturer efficacement le point de puissance maximale global du réseau photovoltaïque partiellement ombré. L'un de ces trackers est l'algorithme d'optimisation d'essaim de particules (PSO) qui est l'une des techniques de calcul logiciel. Les trackers conventionnels basés sur PSO présentent de nombreux avantages tels que la simplicité de mise en œuvre du matériel et l'indépendance par rapport au système installé. Le véritable problème de l'application pratique de PSO est la détermination de ses paramètres pour assurer une grande efficacité d'extraction du MPP mondial. L'analyse des articles scientifiques consacrés à l'algorithme PSO a montré qu'il n'existe actuellement aucune méthodologie pour la sélection des paramètres optimaux des suiveurs de puissance maximale basés sur l'algorithme PSO pour le système PV. Cet article vise à créer une méthode pratique et raisonnable pour choisir les paramètres optimaux de l'algorithme PSO, en tenant compte de la topologie et des paramètres du convertisseur DC-DC et de la configuration des panneaux solaires. Une nouvelle méthode de sélection des paramètres d'un convertisseur abaisseur de tension connecté à une batterie a été présentée. La valeur optimale du temps d'échantillonnage pour les contrôleurs MPP numériques, fournissant leurs performances maximales ; a été déterminée sur la base d'une nouvelle méthodologie. Le progiciel Matlab/Simulink est utilisé comme principal outil de recherche. Les principaux résultats identifient que le PSO modifié et ses paramètres conçus répondent le mieux aux exigences du contrôleur MPPT pour le système PV. One of the important tasks for increasing the efficiency of photovoltaic (PV) system is the development and improvement of the maximum power point tracking algorithms (MPPT). These MPPT algorithms lead to the ability to catch efficiently the global maximum power point of the partially shaded PV array. One of these trackers is the particle swarm optimization (PSO) algorithm which is one of the Soft computing techniques. The conventional PSO based trackers have many advantages such as the simplicity of hardware implementation and independence from the installed system. The actual problem of the practical application of PSO is the determination of its parameters to ensure high effectiveness of extracting the global MPP. Analysis of scientific papers devoted to the PSO algorithm has shown that there is currently no methodology for the optimal parameters' selection of PSO algorithm based maximum power trackers for the PV system. This paper aims to create a convenient and reasonable method for choosing the optimal parameters of the PSO algorithm, taking into account the topology and parameters of the DC-DC converter and the configuration of solar panels. A new method for selecting the parameters of a buck converter connected to a battery has been presented. The optimal value of the sampling time for the digital MPP controllers, providing their maximum performance; has been determined based on a new methodology. Matlab/Simulink software package is used as the main research tool. The prominent outcomes identify that the modified PSO and its designed parameters best meet the requirements of the MPPT controller for the PV system. تتمثل إحدى المهام المهمة لزيادة كفاءة النظام الكهروضوئي (PV) في تطوير وتحسين خوارزميات تتبع نقطة الطاقة القصوى (MPPT). تؤدي خوارزميات MPPT هذه إلى القدرة على التقاط نقطة الطاقة القصوى العالمية للمصفوفة الكهروضوئية المظللة جزئيًا بكفاءة. أحد أجهزة التتبع هذه هي خوارزمية تحسين سرب الجسيمات (PSO) التي تعد واحدة من تقنيات الحوسبة اللينة. تتمتع أجهزة التتبع التقليدية التي تعتمد على PSO بالعديد من المزايا مثل بساطة تنفيذ الأجهزة والاستقلال عن النظام المثبت. تتمثل المشكلة الفعلية للتطبيق العملي لـ PSO في تحديد معاييره لضمان فعالية عالية لاستخراج MPP العالمي. أظهر تحليل الأوراق العلمية المخصصة لخوارزمية PSO أنه لا توجد حاليًا منهجية لاختيار المعلمات المثلى لأجهزة تتبع الطاقة القصوى القائمة على خوارزمية PSO للنظام الكهروضوئي. تهدف هذه الورقة إلى إنشاء طريقة مريحة ومعقولة لاختيار المعلمات المثلى لخوارزمية PSO، مع مراعاة طوبولوجيا ومعلمات محول DC - DC وتكوين الألواح الشمسية. تم تقديم طريقة جديدة لاختيار معلمات محول باك المتصل بالبطارية. تم تحديد القيمة المثلى لوقت أخذ العينات لوحدات تحكم MPP الرقمية، مما يوفر أقصى أداء لها ؛ بناءً على منهجية جديدة. تُستخدم حزمة برامج Matlab/Simulink كأداة بحث رئيسية. تحدد النتائج البارزة أن PSO المعدل ومعلماته المصممة تلبي على أفضل وجه متطلبات وحدة تحكم MPPT للنظام الكهروضوئي.

The sudden increase in the concentration of carbon dioxide (CO2) in the atmosphere due to the high dependency on fossil products has created the need for an urgent solution to mitigate this challenge. Global warming, which is a direct result of excessive CO2 emissions into the atmosphere, is one major issue that the world is trying to curb, especially in the 21st Century where most energy generation mediums operate using fossil products. This investigation considered a number of materials ideal for the capturing of CO2 in the post-combustion process. The application of aqueous ammonia, amine solutions, ionic liquids, and activated carbons is thoroughly discussed. Notable challenges are impeding their advancement, which are clearly expatiated in the report. Some merits and demerits of these technologies are also presented. Future research directions for each of these technologies are also analyzed and explained in detail. Furthermore, the impact of post-combustion CO2 capture on the circular economy is also presented.