• Energy Research

Abstract Rising demand for energy resources alongside climate emergency concerns has attracted the urgent attention of researchers towards the preparation and utilization of biofuels. This review will investigate the different generations of biofuels and more particularly, the developmental and production processes for creating liquid biofuels. Initially, the first-generation biofuel was dependent on edible resources, which has caused controversy and arguments on whether to fulfil the “food or fuel requirement” for civilization. Second-generation biofuels employed inedible resources, however, the cost of production at a commercial scale has restricted its expansion. Recently, third and fourth-generation use microorganisms and genetically modified microorganisms, respectively, to produce biofuels and create an efficient synthetic fuel switch route. Although the last two generations are still in the developmental phase, thorough research is required before commercial-scale production. In conclusion, this review has found that first- and second-generation biofuel production approaches will soon be inadequate to satisfy the exponentially rising demand for biofuels. Therefore, substantial research efforts currently and in the future should focus on the production of third and fourth-generation biofuels, especially on engineered microorganisms. Ultimately, the structure of this review is to outline the current state of the art research regarding biofuels, their production processes and limitations/challenges. This was done through critically reviewing the most up-to-date literature and utilizing bibliometric analysis tools to put forward the guidelines for the future routes of the four generations of biofuels.

Les systèmes énergétiques sont dynamiques et en transition en raison des ressources énergétiques alternatives, des innovations technologiques, de la demande, des coûts et des conséquences environnementales. Les combustibles fossiles sont les sources de production d'énergie traditionnelle, mais ils sont progressivement passés aux technologies innovantes actuelles, en mettant l'accent sur les ressources renouvelables comme le solaire et l'éolien. Malgré des augmentations constantes des prix de l'énergie, les demandes des clients augmentent rapidement en raison de l'augmentation de la population, du développement économique, de la consommation par habitant, de l'approvisionnement dans des endroits éloignés et sous forme statique pour les machines et les appareils portables. Le stockage d'énergie peut permettre une production et une livraison flexibles d'électricité stable pour répondre aux demandes des clients. Les exigences en matière de stockage d'énergie deviendront le triple des valeurs actuelles d'ici 2030 pour lesquelles des dispositifs et des systèmes très spéciaux sont nécessaires. L'objectif de la présente recherche d'examen est de comparer et d'évaluer les dispositifs et les systèmes actuellement utilisés et prévus pour l'avenir. Les questions économiques et environnementales ainsi que les défis et les limites ont été élaborés grâce à une consultation approfondie et forte de la littérature, des recherches antérieures, des rapports et des revues. Les technologies telles que les batteries à flux, les supercondensateurs, LES PME (stockage d'énergie magnétique supraconductrice), les FES (Flywheel Energy Storage), les PHS (stockage hydraulique par pompage), les tes (stockage d'énergie thermique), les CAE (stockage d'énergie à air comprimé) et les HES (stockage d'énergie hybride) ont été discutées. Cet article peut contribuer à guider les décideurs et les praticiens s'ils veulent sélectionner les dispositifs et systèmes de stockage d'énergie les plus récents et les plus innovants pour leurs réseaux et d'autres utilisations associées comme les machines et les appareils portables. Les caractéristiques, les avantages, les limites, les coûts et les considérations environnementales ont été comparés à l'aide de tableaux et de démonstrations pour faciliter leur décision finale et la gestion des problèmes émergents. Ainsi, les résultats de cette étude d'examen peuvent s'avérer très utiles pour diverses parties prenantes du secteur de l'énergie. Los sistemas energéticos son dinámicos y transitorios debido a los recursos energéticos alternativos, las innovaciones tecnológicas, la demanda, los costes y las consecuencias ambientales. Los combustibles fósiles son las fuentes de generación de energía tradicional, pero se ha hecho una transición gradual a las tecnologías innovadoras actuales con énfasis en los recursos renovables como la solar y la eólica. A pesar de los constantes aumentos en los precios de la energía, las demandas de los clientes están aumentando rápidamente debido a un aumento en las poblaciones, el desarrollo económico, el consumo per cápita, el suministro en lugares remotos y en formas estáticas para máquinas y dispositivos portátiles. El almacenamiento de energía puede permitir la generación flexible y el suministro de electricidad estable para satisfacer las demandas de los clientes. Los requisitos para el almacenamiento de energía se convertirán en el triple de los valores actuales para 2030, para lo cual se requieren dispositivos y sistemas muy especiales. El objetivo de la investigación de revisión actual es comparar y evaluar los dispositivos y sistemas actualmente en uso y anticipados para el futuro. Los problemas económicos y ambientales, así como los desafíos y limitaciones, se han elaborado a través de una consulta profunda y sólida de la literatura, investigaciones previas, informes y revistas. Se han discutido las tecnologías como baterías de flujo, supercondensadores, SME (Superconducting magnetic energy storage), FES (Flywheel Energy Storage), PHS (Pumped hydro storage), tes (Thermal Energy Storage), caes (Compressed Air Energy Storage) y HES (Hybrid energy storage). Este artículo puede contribuir a guiar a los responsables de la toma de decisiones y a los profesionales si desean seleccionar los dispositivos y sistemas de almacenamiento de energía más recientes e innovadores para sus redes y otros usos asociados, como máquinas y dispositivos portátiles. Las características, ventajas, limitaciones, costos y consideraciones ambientales se han comparado con la ayuda de tablas y demostraciones para facilitar su decisión final y la gestión de los problemas emergentes. Por lo tanto, los resultados de este estudio de revisión pueden resultar muy útiles para varias partes interesadas del sector energético. Energy systems are dynamic and transitional because of alternative energy resources, technological innovations, demand, costs, and environmental consequences. The fossil fuels are the sources of traditional energy generation but has been gradually transitioned to the current innovative technologies with an emphasis on renewable resources like solar, and wind. Despite consistent increases in energy prices, the customers' demands are escalating rapidly due to an increase in populations, economic development, per capita consumption, supply at remote places, and in static forms for machines and portable devices. The energy storage may allow flexible generation and delivery of stable electricity for meeting demands of customers. The requirements for energy storage will become triple of the present values by 2030 for which very special devices and systems are required. The objective of the current review research is to compare and evaluate the devices and systems presently in use and anticipated for the future. The economic and environmental issues as well as challenges and limitations have been elaborated through deep and strong consultation of literature, previous research, reports and journal. The technologies like flow batteries, super capacitors, SMES (Superconducting magnetic energy storage), FES (Flywheel Energy Storage), PHS (Pumped hydro storage), TES (Thermal Energy Storage), CAES (Compressed Air Energy Storage), and HES (Hybrid energy storage) have been discussed. This article may contribute to guide the decision-makers and the practitioners if they want to select the most recent and innovative devices and systems of energy storage for their grids and other associated uses like machines and portable devices. The characteristics, advantages, limitations, costs, and environmental considerations have been compared with the help of tables and demonstrations to ease their final decision and managing the emerging issues. Thus, the outcomes of this review study may prove highly useful for various stakeholders of the energy sector. تتسم أنظمة الطاقة بالديناميكية والانتقال بسبب موارد الطاقة البديلة والابتكارات التكنولوجية والطلب والتكاليف والعواقب البيئية. الوقود الأحفوري هو مصادر توليد الطاقة التقليدية ولكن تم نقله تدريجياً إلى التقنيات المبتكرة الحالية مع التركيز على الموارد المتجددة مثل الطاقة الشمسية وطاقة الرياح. على الرغم من الزيادات المستمرة في أسعار الطاقة، فإن طلبات العملاء تتصاعد بسرعة بسبب الزيادة في عدد السكان، والتنمية الاقتصادية، واستهلاك الفرد، والإمدادات في الأماكن النائية، وفي أشكال ثابتة للآلات والأجهزة المحمولة. قد يسمح تخزين الطاقة بتوليد وتوصيل الكهرباء المستقرة بشكل مرن لتلبية متطلبات العملاء. ستصبح متطلبات تخزين الطاقة ثلاثة أضعاف القيم الحالية بحلول عام 2030 والتي تتطلب أجهزة وأنظمة خاصة جدًا. الهدف من بحث المراجعة الحالي هو مقارنة وتقييم الأجهزة والأنظمة المستخدمة حاليًا والمتوقعة للمستقبل. تم توضيح القضايا الاقتصادية والبيئية وكذلك التحديات والقيود من خلال التشاور العميق والقوي للأدبيات والبحوث السابقة والتقارير والمجلات. تمت مناقشة التقنيات مثل بطاريات التدفق، والمكثفات الفائقة، والشركات الصغيرة والمتوسطة (تخزين الطاقة المغناطيسية فائقة التوصيل)، و FES (تخزين طاقة الحدافة)، و PHS (التخزين المائي المضخ)، و TES (تخزين الطاقة الحرارية)، و CAES (تخزين طاقة الهواء المضغوط)، و HES (تخزين الطاقة الهجين). قد تساهم هذه المقالة في توجيه صانعي القرار والممارسين إذا كانوا يرغبون في اختيار أحدث الأجهزة والأنظمة المبتكرة لتخزين الطاقة لشبكاتهم والاستخدامات الأخرى المرتبطة بها مثل الآلات والأجهزة المحمولة. تمت مقارنة الخصائص والمزايا والقيود والتكاليف والاعتبارات البيئية بمساعدة الجداول والعروض التوضيحية لتسهيل قرارها النهائي وإدارة القضايا الناشئة. وبالتالي، قد تكون نتائج هذه الدراسة الاستعراضية مفيدة للغاية لمختلف أصحاب المصلحة في قطاع الطاقة.

In this paper the dynamics of a single machine connected to infinite bus power system is analyzed. Such analysis requires a certain level of system modeling. The main system components models are the synchronous machine, excitation system and the Power System Stabilizer. The Matlab/Simulink is used as a programming tool to analyze the system performance. According to the system performance a proper design for the Power System Stabilizer (PSS) using Genetic Algorithm (GA) is carried out. Then the designed PSS is implemented in the model and the dynamic system response is analyzed. Since the simulation results without PSS showed unacceptable system response, the system response with the PSS has improved and the PSS succeeded to stabilize an unstable system. The designed PSS has been implemented in a microcontroller. Finally, the system response with PSS-microcontroller has been tested and compared with the simulation results.

This paper presents small-disturbance stability studies of the interconnected power systems of the Sultanate of Oman and the State of the United Arab Emirates. The two systems are interconnected through the existing 220 kV double circuit transmission line between Oman and Abu Dhabi leading to a rather longitudinal structure power system. The objective of the paper is to assess the inter-area oscillation damping of this interconnected system during small amplitude disturbances by using eigenvalue analysis. A detailed model of the interconnected system is obtained including representation of generators, prime movers, speed governors, exciters, automatic voltage regulators, transmission lines, transformers, compensators and loads. The system eigenvalues are calculated at various operating scenarios, including peak and minimum loading conditions with zero and maximum power exchanges in both directions and also during N and N-1 conditions. The results have shown that both systems have adequate damping before being interconnected. After interconnection, the eigenvalues profile indicates that the system will remain stable and satisfactorily damped for the considered power exchanges.

This paper presents a case study about the impacts of industrial loads on power quality. A review of harmonics causes, negative impacts, mitigation techniques, quantification indices and limits are presented. Moreover, harmonics measurements at three grid station that supply the three main industrial areas located in the Main Interconnected System (MIS) of Oman are conducted. Measurement results are compared with limits specified by national and international standards.

This research aims to support the goals of Oman Vision 2040 by reducing the dependency on non-renewable energy resources and increasing the utilization of the national natural renewable energy resources. Selecting appropriate energy storage systems (ESSs) will play a key role in achieving this vision by enabling a greater integration of solar and other renewable energy. ESSs allow for solar power generated during daylight hours to be stored for use during peak demand periods. Additionally, the proposed framework provides guidance for large-scale ESS infrastructure planning and investments to support Oman’s renewable energy goals. As the global renewable energy market grows rapidly and Oman implements economic reforms, the ESS market is expected to flourish in Oman. In the near future, ESS is expected to contribute to lower electricity costs and enhance stability compared to traditional energy systems. While ESS technologies have been studied broadly, there is a lack of comprehensive analysis for optimal ESS selection tailored to Oman’s unique geographical, technical, and policy context. The main objective of this study is to provide a comprehensive evaluation of ESS options and identify the type(s) most suitable for integration with Oman’s national grid using a multi-criteria decision-making (MCDM) methodology. This study addresses this gap by applying the Hesitate Fuzzy Analytic Hierarchy Process (HF-AHP) and Hesitate Fuzzy VIKOR methods to assess alternative ESS technologies based on technical, economic, environmental, and social criteria specifically for Oman’s context. The analysis reveals pumped hydro energy storage (PHES) and compressed air energy storage (CAES) as the most appropriate solutions. The tailored selection framework aims to guide policy and infrastructure planning to determine investments for large-scale ESSs and provide a model for comprehensive ESS assessment in energy transition planning for countries with similar challenges.

A main feature of future smart grids is their self-healing capability, which allows fault location, isolation and service restoration to be done automatically. Restoration is a combinatorial non-linear optimization problem for which conventional mathematical programming techniques and heuristic methods become computationally very costly. This paper proposes a decentralized restoration method that avoids the computational burden of fully centralized optimization techniques while still providing good solutions and avoiding single points of failure. By pre-calculating the amount of power that can be transferred from other feeders without violating their limits, restoration within the outage area is converted into a binary integer linear optimization problem which can be easily solved. To prove its effectiveness, different case scenarios were tested on 14-bus and 70-bus systems. The multi-agent system was implemented in JAVA Agent Development Framework (JADE) and MATLAB was employed for the main algorithms within each agent. The outcomes were compared to those of previously proposed centralized and decentralized approaches, proving that the method proposed shows better computational efficiency than the centralized approach and better results than the decentralized approach. Therefore, the proposed algorithm provides an overall improved solution.

Using PMU data, the fault location algorithm has gradually been trended in the literature. Besides the optimality of the algorithm, the fault location application should directly receive the data of the faulty line from the PMU devices to have the best performance; using state estimation to create the input data of fault location algorithm not only wastes the golden time, but it also decreases the reliability. Given, it is not possible to install PMU devices in all buses of the system, it is better to install them for the lengthy lines having the most probability of the failure. Although various approaches have been presented in the literature to solve optimal PMU placement (OPP), the fault location observability has less been considered in OPP formulation Accordingly, this paper considers a new index, named fault location observability (FLO), as a second objective function in its OPP formulation. Using this index, in addition to minimizing PMU installation cost, the number of lengthy lines being directly observable are also maximized. Using the ɛ-constraint method, the multi-objective problem has been solved several times as single-objective optimizations. Given the constraints and objective functions are linear, the work presents a mixed integer linear programming (MILP) formulation for the placement problem. Using the GAMS under CPLEX solver, the global optimal solutions of MILP model corresponding to the various ɛ-constraints yields to a Pareto optimal front. The simulation results, next, implements the proposed method on the IEEE 300 bus test system as well as the practical OMAN grid to prove the effectiveness of the proposed method.