• Energy Research

As wind energy is widely available, an increasing number of individuals, especially in off-grid rural areas, are adopting it as a dependable and sustainable energy source. The energy of the wind is harvested through a device known as a wind energy harvesting system (WEHS). These systems convert the kinetic energy of wind into electrical energy using wind turbines (WT) and electrical generators. However, the output power of a wind turbine is affected by various factors, such as wind speed, wind direction, and generator design. In order to optimize the performance of a WEHS, it is important to track the maximum power point (MPP) of the system. Various methods of tracking the MPP of the WEHS have been proposed by several research articles, which include traditional techniques such as direct power control (DPC) and indirect power control (IPC). These traditional methods in the standalone form are characterized by some drawbacks which render the method ineffective. The hybrid techniques comprising two different maximum power point tracking (MPPT) algorithms were further proposed to eliminate the shortages. Furtherly, Artificial Intelligence (AI)-based MPPT algorithms were proposed for the WEHS as either standalone or integrated with the traditional MPPT methods. Therefore, this research focused on the review of the AI-based MPPT and their performances as applied to WEHS. Traditional MPPT methods that are studied in the previous articles were discussed briefly. In addition, AI-based MPPT and different hybrid methods were also discussed in detail. Our study highlights the effectiveness of AI-based MPPT techniques in WEHS using an artificial neural network (ANN), fuzzy logic controller (FLC), and particle swarm optimization (PSO). These techniques were applied either as standalone methods or in various hybrid combinations, resulting in a significant increase in the system’s power extraction performance. Our findings suggest that utilizing AI-based MPPT techniques can improve the efficiency and overall performance of WEHS, providing a promising solution for enhancing renewable energy systems.

With the rise in the demand for electric vehicles, the need for a reliable charging infrastructure increases to accommodate the rapid public adoption of this type of transportation. Simultaneously, local electricity grids are being under pressure and require support from naturally abundant and inexpensive alternative energy sources such as wind and solar. This is why the world has recently witnessed the emergence of renewable energy-based charging stations that have received great acclaim. In this paper, we review studies related to this type of alternative energy charging infrastructure. We provide comprehensive research covering essential aspects in this field, including resources, potentiality, planning, control, and pricing. The study also includes studying and clarifying challenges facing this type of electric charging station and proposing suitable solutions for those challenges. The paper aims to provide the reader with an overview of charging electric vehicles through renewable energy and establishing the ground for further research in this vital field.

Abstract In this present work, we report a novel fabrication technique of ternary Cu2SnS3 (CTS) thin films by sulphurization of sequentially sputtered Sn/CuSn (elemental/alloy) stacked metallic precursors. The focal aim of our investigation is on the impact of metallic precursors’ Cu/Sn ratio on the overall material properties of CTS films, which in turn, influence the photovoltaic device performance. All CTSs exhibited polycrystalline films with a mixture monoclinic CTS and orthorhombic SnS compound, p-type conductivity, and optical band gap in the range of 0.84–0.90 eV. Metallic precursor with Cu/Sn ratio of 1.09 produced optimum CTS film with post-sulphurization Cu/Sn ratio of 1.98 and highest conversion efficiency of 0.71%, respectively, despite exhibiting pronounced formation of SnS secondary phase. The correlation between XRD, Raman, and SEM-EDX outcomes revealed that CTS films from metallic precursors with Cu/Sn ratio higher than 1.09 undergo severe microstructural degradation due to Sn-loss through decomposition of volatile SnS phase and consequently, resulted in poorer absorber layer quality and lower device performance. Finally, several efficiency impeding factors are discussed and practical propostions to overcome them are presented.

AbstractAccurate state of charge (SOC) estimation of lithium-ion (Li-ion) batteries is crucial in prolonging cell lifespan and ensuring its safe operation for electric vehicle applications. In this article, we propose the deep learning-based transformer model trained with self-supervised learning (SSL) for end-to-end SOC estimation without the requirements of feature engineering or adaptive filtering. We demonstrate that with the SSL framework, the proposed deep learning transformer model achieves the lowest root-mean-square-error (RMSE) of 0.90% and a mean-absolute-error (MAE) of 0.44% at constant ambient temperature, and RMSE of 1.19% and a MAE of 0.7% at varying ambient temperature. With SSL, the proposed model can be trained with as few as 5 epochs using only 20% of the total training data and still achieves less than 1.9% RMSE on the test data. Finally, we also demonstrate that the learning weights during the SSL training can be transferred to a new Li-ion cell with different chemistry and still achieve on-par performance compared to the models trained from scratch on the new cell.

Abstract Thermoelectric technology is a promising solution to recover waste heat from different resources. There are numerous researches in the literature that measure performance of thermoelectric modules (TEMs). A comprehensive review of research studies that classifies and expounds disparities between various thermoelectric power generation (TEPG) systems is still unavailable and therefore, this paper reviews major concerns on their designs and performances. Firstly, various main elements of TEPG systems, which affect the output power of TEMs such as stabilizer or heat exchanger, interface, contact pressure, insulation, cooling system, and integrity are studied. Secondly, performances of test rigs and various prototypes are reviewed in detail based on their cooling methods since cooling is the most prominent factor among other counterparts. In general, the cooling unit is divided into either passive or active cooling system, which is selected based on its well-defined use. A comprehensive study on various test rigs with active cooling systems is given while a broader range in prototypes is covered and classified under detailed surveys. This review is expected to be of value for researchers in the field of thermoelectric. Overall, in order to have a prospective future towards commercialization of TEPG systems, the existing prototypes in the literature are still subjected to many enhancements in their design aspects, while further improvements are needed to be achieved independently in TEMs’ development.

Los recientes avances en la tecnología de células solares CdTe han introducido la integración de sustratos flexibles, proporcionando soluciones de energía ligeras y adaptables para diversas aplicaciones. Algunas de las aplicaciones notables de la tecnología solar fotovoltaica flexible incluyen la construcción de sistemas fotovoltaicos integrados (BIPV), transporte, aeroespacial, satélites, etc. Sin embargo, a pesar de este avance, ciertos problemas relacionados con el metal y el p-CdTe seguían sin resolverse. Además, la fabricación de un dispositivo de trabajo completo sobre vidrio flexible es un desafío y requiere una consideración especial debido a la morfología inestable y las propiedades estructurales de la película depositada sobre sustratos de vidrio ultrafinos. La brecha existente en el conocimiento sobre el vasto potencial de las células solares flexibles de CdTe en sustratos UTG y sus posibles aplicaciones bloquea su utilización de plena capacidad. Por lo tanto, este documento de revisión exhaustivo se concentra exclusivamente en los obstáculos asociados con la implementación de células solares de CdTe en sustratos UTG con una capa potencial de campo de superficie posterior (BSF). La importancia de este estudio radica en su meticulosa identificación y análisis de los desafíos sustanciales asociados con la integración de CdTe flexible en sustratos UTG y el aprovechamiento de ZnTe dopado con Cu como una posible capa de BSF para mejorar el rendimiento de las células solares de CdTe flexibles. Les progrès récents de la technologie des cellules solaires CdTe ont introduit l'intégration de substrats flexibles, offrant des solutions énergétiques légères et adaptables pour diverses applications. Certaines des applications notables de la technologie photovoltaïque solaire flexible comprennent la construction de systèmes photovoltaïques intégrés (BIPV), le transport, l'aérospatiale, les satellites, etc. Cependant, malgré cette avancée, certaines questions concernant le métal et le p-CdTe sont restées en suspens. En outre, la fabrication d'un dispositif complet sur verre flexible est difficile et nécessite une attention particulière en raison de la morphologie instable et des propriétés structurelles du film déposé sur des substrats en verre ultra-minces. L'écart existant dans les connaissances sur le vaste potentiel des cellules solaires CdTe flexibles sur les substrats UTG et leurs applications possibles bloque leur pleine utilisation de la capacité. Par conséquent, cet article de synthèse complet se concentre exclusivement sur les obstacles associés à la mise en œuvre de cellules solaires CdTe sur des substrats UTG avec une couche potentielle de champ de surface arrière (BSF). L'importance de cette étude réside dans son identification et son analyse méticuleuses des défis substantiels associés à l'intégration de CdTe flexible sur des substrats UTG et à l'exploitation de ZnTe dopé au Cu comme couche de FBS potentielle pour améliorer les performances des cellules solaires CdTe flexibles. Recent advancements in CdTe solar cell technology have introduced the integration of flexible substrates, providing lightweight and adaptable energy solutions for various applications. Some of the notable applications of flexible solar photovoltaic technology include building integrated photovoltaic systems (BIPV), transportation, aerospace, satellites, etc. However, despite this advancement, certain issues regarding metal and p-CdTe remained unresolved. Besides, the fabrication of a full-working device on flexible glass is challenging and requires special consideration due to the unstable morphology and structural properties of deposited film on ultra-thin glass substrates. The existing gap in knowledge about the vast potential of flexible CdTe solar cells on UTG substrates and their possible applications blocks their full capacity utilization. Hence, this comprehensive review paper exclusively concentrates on the obstacles associated with the implementation of CdTe solar cells on UTG substrates with a potential back surface field (BSF) layer. The significance of this study lies in its meticulous identification and analysis of the substantial challenges associated with integrating flexible CdTe onto UTG substrates and leveraging Cu-doped ZnTe as a potential BSF layer to enhance the performance of flexible CdTe solar cells. أدت التطورات الأخيرة في تكنولوجيا الخلايا الشمسية CdTe إلى دمج الركائز المرنة، مما يوفر حلول طاقة خفيفة الوزن وقابلة للتكيف لمختلف التطبيقات. تشمل بعض التطبيقات البارزة للتكنولوجيا الضوئية الشمسية المرنة بناء أنظمة ضوئية متكاملة (BIPV)، والنقل، والفضاء، والأقمار الصناعية، وما إلى ذلك. ومع ذلك، على الرغم من هذا التقدم، ظلت بعض القضايا المتعلقة بالمعادن و p - CDTe دون حل. إلى جانب ذلك، فإن تصنيع جهاز يعمل بكامل طاقته على الزجاج المرن يمثل تحديًا ويتطلب اهتمامًا خاصًا بسبب التشكل غير المستقر والخصائص الهيكلية للأغشية المودعة على ركائز زجاجية رقيقة جدًا. إن الفجوة الحالية في المعرفة حول الإمكانات الهائلة للخلايا الشمسية CdTe المرنة على ركائز UTG وتطبيقاتها المحتملة تمنع استخدامها الكامل للقدرة. وبالتالي، تركز ورقة المراجعة الشاملة هذه حصريًا على العقبات المرتبطة بتنفيذ الخلايا الشمسية CdTe على ركائز UTG مع طبقة مجال السطح الخلفي المحتملة (BSF). تكمن أهمية هذه الدراسة في تحديدها الدقيق وتحليلها للتحديات الكبيرة المرتبطة بدمج CdTe المرن على ركائز UTG والاستفادة من ZnTe المخدر بالنحاس كطبقة BSF محتملة لتعزيز أداء الخلايا الشمسية CdTe المرنة.