Energy Systems Engineering Research Articles

A novel multi-objective decision-making model to determine optimum resource and capacity configuration for hybrid electricity generation systems: A comparative case study in Türkiye

The rapid depletion of fossil fuels, their negative environmental impacts due to harmful carbon emissions, and the drawbacks of the sole use of intermittent renewable energy resources on system reliability necessitate the use of more advanced energy system technologies. As a result, hybrid electricity generation systems offer an innovative alternative to conventional energy systems. However, the technical complexity and variability of these systems require the application of multi-objective optimization techniques to determine the optimal sizing and system design. Therefore, in this study, we suggest a multi-objective decision-making (MODM) model that involves five conflicting objectives to find the optimal resource configuration and auxiliary source capacity allocation within the framework of the multi-source electricity production method in Türkiye. The MODM model aims to maximize the utilization of resource potentials and the jobs created, while simultaneously minimizing the levelized cost of energy (LCOE), construction duration, and carbon emissions. The MODM model was solved using fmincon and fgoalattain multi-objective optimization algorithms using the Goal Attainment Method in MATLAB and the model results were subsequently compared to the real-world data. According to the model results, the optimal capacity to be allocated for the auxiliary source units is 13,749.58 MWm, while the capacity allocated according to the real-world data as of March 2024 is 2495.49 MWm. In contrast to the model's prediction of 90.8 % solar-based auxiliary unit installations, 99.8 % of auxiliary units are based on solar PV in the actual case. Furthermore, hydro or geothermal-based auxiliary sources are not allocated any capacity, which is consistent with the actual situation. The capacity allocated for the wind (primary source) + solar (auxiliary source) configuration is 76.2 %, whereas in reality, it accounts for 65.6 % of the total installations. Consequently, the model findings suggest that the maximum capacity allocation is for the wind (primary source) + solar (auxiliary source) type hybrid electricity generation system.

OPTIMAL CONTROL OF A HYBRID PV-WIND POWER SYSTEM FOR ISLANDED HYBRID MICROGRID USING MOGA-FUZZY LOGIC CONTROLLER

The paper presents a comprehensive approach to managing the complexities associated with the integration of photovoltaic (PV) and wind energy systems in islanded microgrid environments. These microgrids, often isolated from the main power grid, face unique challenges due to the variability and intermittency of renewable energy sources, which can lead to instability and inefficiencies in power supply. To address these challenges, the study introduces a novel control strategy that combines a Multi-Objective Genetic Algorithm (MOGA) with a Fuzzy Logic Controller. The MOGA is utilized to explore a broad solution space and identify optimal control parameters that balance multiple objectives, including minimizing power fluctuations, maximizing the utilization of renewable energy, and ensuring a stable and reliable power supply. This optimization is crucial in islanded microgrids, where the lack of a larger grid connection necessitates highly efficient and responsive energy management systems to maintain stability. The Fuzzy Logic Controller, on the other hand, provides a flexible and adaptive control mechanism that responds to the dynamic and often unpredictable nature of renewable energy generation. By interpreting input variables in a way that mimics human decision-making, the Fuzzy Logic Controller can effectively handle the inherent uncertainties and non-linearities in the power system, adjusting the operation of the PV and wind power sources, as well as any supplementary energy storage systems, to optimize performance. This adaptive capability is particularly beneficial in scenarios where rapid changes in weather conditions can significantly impact energy generation and consumption patterns. The integration of MOGA with Fuzzy Logic not only enhances the decisionmaking process but also allows for the simultaneous consideration of multiple objectives, which is a critical advancement over traditional single-objective optimization techniques. This dual approach ensures that the hybrid PV-wind power system operates at its highest efficiency, balancing the need for sustainability with the practical requirements of reliability and economic viability. The results from extensive simulations, which model various operational scenarios and disturbances, demonstrate that the proposed MOGA-Fuzzy Logic Controller significantly improves the stability and efficiency of the islanded microgrid. The system is shown to effectively manage power flows, reduce dependency on fossil fuel-based backup generators, and increase the overall penetration of renewable energy. The proposed MOGA-Fuzzy Logic Controller stands out as a promising solution for the optimal control of hybrid PV-wind power systems, offering a viable pathway for achieving sustainable energy goals in islanded and other decentralized grid settings. This work not only advances academic knowledge but also has practical implications for the design and operation of future energy systems, making it a significant contribution to the field of renewable energy and power system engineering.

Investigating the influence of erratic grid on stationary battery energy storage technologies in hybrid power systems: Techno-environ-economic perspectives

Several obstacles impede renewable energy penetration into the global energy sector. Amongst the apparent challenges which require credible research attention, is the selection of appropriate energy storage technologies in the context of intermittent renewable resources and frequent grid outages. Given these, the present study investigated the technical, economic, and environmental effects of an erratic national grid on four distinct battery technologies in hybrid wind, solar, and diesel energy systems. The study was conducted at Baze University Abuja, Nigeria using the Hybrid Optimization Model for Electric Renewables software. The battery types considered are vanadium redox flow battery (VRB), lead-acid battery, nickel-iron battery, and lithium-ion battery (LIB). The VRB-based hybrid energy systems demonstrated superior performances in meeting the electricity demands of the university at the lowest net present cost, levelized cost of energy, and carbon dioxide emissions of $6,328,003.00, $0.0722/kWh, and 21,754 kg/year respectively. This battery technology is characterized by storage depletion, throughput, and losses of 796 kWh/year, 406,570 kWh/year, and 182,757 kWh/year respectively. The sensitivity analysis showed that the frequency and duration of main grid outages affect the optimal systems’ economics, component sizes, battery energy losses, battery energy storage depletion, and renewable energy penetration.

A review of the state of art and prospects in energy storage systems for energy harvesting applications

Due to the increasing trend in worldwide energy consumption, many new energy technology systems have emerged in the past decades. The implementation of energy storage system (ESS) technology in energy harvesting systems is significant to achieve flexibility and reliability in fulfilling the load demands. In this paper, several types of energy storage technologies available in the market are discussed to view their benefits and drawbacks. The main aim of this review is to provide a platform for readers especially those who seek to know more about ESS at a glance, to decide which ESS technology is best suited for any specific applications. This review would serve as a base for the initial state to make the right decision by referring to the criterias and characteristics of energy resources to get the optimal ESS technology. A comprehensive comparison among the various types of ESS technologies is outlined and elaborated to provide a better and clearer picture to the readers. Last but not least, the relevant recommendations and alternative choices for services related to the harvesting of solar PV energy are described too. It is hoped that the findings of this review article may be helpful to all readers interested in ESS technology.

Phase transition of multiple encapsulated PCMs in a U-shaped channel under MHD with ternary nanofluid

Purpose Multiple encapsulated phase change materials (PCMs) are used in a wide range of applications, including convective drying, electronic cooling, waste heat recovery and air conditioning. Therefore, it is important to understand the performance of multiple PCMs in channels with flow separation and develop methods to increase their effectiveness. The aim of the study is to analyze the phase transition dynamics of multiple encapsulated PCMs mounted in a U-shaped tube under inclined magnetic field by using ternary nanofluid. Design/methodology/approach The PCMs used in the upper horizontal channel, vertical channel and lower horizontal channel are denoted by M1, M2 and M3. Magnetic field is uniform and inclined while finite element method is used as the solution technique. Triple encapsulated-PCM system study is carried out taking into account different values of Reynolds number (Re, ranges from 300 to 1,000), Hartmann number (Ha ranges from 0 and 60), magnetic field inclination (between 0 and 90) and solid volume fraction of ternary nanofluid (between 0 and 0.03). The dynamic response of the liquid fraction is estimated for each PCM with varying Re, Ha and t using an artificial neural network. Findings It is observed that for PCMs M2 and M3, the influence of Re on the phase transition is more effective. For M2 and M3, entire transition time (t-F) lowers by approximately 47% and 47.5% when Re is increased to its maximum value, whereas it only falls by 10% for M1. The dynamic characteristics of the phase transition are impacted by imposing MGF and varying its strength and inclination. When Ha is raised from Ha = 0 to Ha = 50, the t-F for PCM-M2 (PCM-M3) falls (increases) by around 30% (29%). For PCMs M1, M2 and M3, the phase transition process accelerates by around 20%, 30% and 28% when the solid volume fraction is increased to its maximum value. Originality/value Outcomes of this research is useful for understanding the phase change behavior of multiple PCMs in separated flow and using various methods such as nano-enhanced magnetic field to improve their effectiveness. Research outputs are beneficial for initial design and optimization of using multiple PCMs in diverse energy system technologies, including solar power, waste heat recovery, air conditioning, thermal management and drying.

Experimental Study on the Effect of Foil Guide Vane on the Performance of a Straight-Blade Vertical Axis Ocean Current Turbine

Indonesia is a country that has enormous energy potential for ocean currents, but the speed of ocean currents is relatively low. The straight-blade vertical axis ocean current turbines can be used to generate electricity. However, one of the disadvantages is lower performance compared to horizontal axis turbines. This study aims to improve the performance of straight-blade vertical axis ocean current turbines using a foil guide vane (FGV). Experimental studies have been conducted in a water tunnel at the Energy Systems Engineering Laboratory, Institut Teknologi Sumatera (ITERA), South Lampung, Indonesia. The investigation is carried out in two stages: the straight-blade without FGV as the original object; the straight-blade with FGV as a variation to improve the turbine performance. The investigation results show that the FGV can enhance the performance of straight-blade vertical axis ocean current turbines such as self-starting, torque coefficient (C_t), and power coefficient (C_p). The FGV has increased self-starting capability at a minimum current speed of 0.078 m/s by 15.3 rpm. The increase in maximum torque coefficient (C_t max) and power coefficient (C_p max) due to the FGV is 32% and 20%, respectively, with a C_t max of 0.829 and 〖a C〗_p max of 0.519. In addition, an investigation was also carried out on flow visualization. It showed that FGV could absorb a lot of injection ink, which means that the turbine with FGV absorbs more kinetic energy than without FGV.

MATHEMATICAL MODELING AND EVALUATION OF THERMODYNAMIC PERFECTION OF A CHEMICAL REACTOR

The development of a formalized mathematical model for quantitative and qualitative assessment of the thermodynamic perfection of a gas chemical reactor is described in the article. The reactor was considered as an energy technology system, that is, in the unity of the transformation of matter and energy. Mathematical modeling and evaluation of the thermodynamic perfection of a chemical reactor is generalized to a class of known chemically active gas systems characteristic of ammonia synthesis, sulfur dioxide oxidation, methanol synthesis, nitric oxide oxidation, etc. The equilibrium degree of transformation of a substance and exergy are taken as the determining parameters for modeling and evaluating the thermodynamic perfection of a chemical reactor. These parameters are functions of temperature and reflect the opposing tendencies of the process when it changes, the evaluation of which allows us to quantify the finding of the maximum exergy in the coordinates (E-T) when justifying the optimal temperatures of the process. The model was tested on a specific example of a sulfur dioxide oxidation reactor in the production of sulfuric acid. The public Octave programming environment was used for computer modeling. The developed mathematical model is recommended to be used in the operational preparation and optimization of the initial data for the design of gas reactors. The mathematical model can be supplemented with a mathematical model developed by the authors earlier for quantifying the current profile of the degrees of transformation of the target component of a chemically active reactive gas mixture in the course of its movement in a polytropic tubular reactor of the "pipe in a pipe" type. After testing and setting up the model in practice, it can be used in an automated control system for chemical reactors, including when creating adaptive control systems. For citation: Andreev A.S., Aksenchik K.V. Mathematical modeling and evaluation of thermodynamic perfection of a chemical reactor. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2024. V. 67. N 5. P. 114-120. DOI: 10.6060/ivkkt.20246705.6964.

Thermal Marangoni convection in two-phase quadratic convective flow of dusty MHD trihybrid nanofluid with non-linear heat source

The current study examines the effect of heat generation on thermal Marangoni convective boundary layer flow of dusty trihybrid nanofluid across a flat surface with thermal radiation and non-linear mixed convection. We consider, two phase dusty liquid model with non-linear heat generation. The fluctuation of surface tension gradients leads to the discovery of Marangoni convection. It can be used for growing crystals, drying silicon wafers, stabilising soap films, and wielding. The main objective of this study is to ascertain the trihybrid nanofluid thermal mobility. A trihybrid nanofluid consisting of magnesium oxide (Mgo), titanium oxide (TiO2), silver (Ag) and water as the base fluid is used. This model can improve the efficiency and dependability of thermal systems in a variety of applications by helping to optimize heat transfer processes in materials processing, electronics cooling, and the creation of cutting-edge cooling technologies in energy systems. The existing PDEs are converted into nonlinear ODEs via similarity variables. The nonlinear ODEs are then solved numerically using shooting technique (RKF-45th approach). When the Marangoni convection parameter rises, higher surface tension gradients lead to stronger induced flows and more efficient heat transfer inside the liquid. As the temperature profiles of the dust and fluid phases drop, the distribution of these characteristics in the liquid becomes more homogeneous.

Analysis of energy intensity indicators in production of mineral fertilizers

The article presents the results of the calculation of the energy consumption of the main and auxiliary technologies for the production of mineral fertilizers, interrelated as a single energy technology system (ETS). At the stage of the primary analysis of fuel, electricity and heat consumption indicators of individual technologies of the mineral fertilizers industry, the task was set to determine the energy intensity of specific technologies depending on intra-system distribution of flows of fuel and energy resources (FER) between the ETS production facilities for the output of target products.On the basis of a mathematical model, according to the averaged specific consumption rates of fuel and energy resources of the main and auxiliary technologies for the production of one ton of product, the values of specific energy consumption for target technologies for the production of mineral fertilizers were obtained. The analysis of the calculated indicators of energy consumption enabled to identify the most energy-intensive technologies.. It is shown that in the total energy consumption of the target technology, the share of energy consumption of auxiliary industries is up to 97% of the total energy intensity. Besides, the paper cosiders the key factors that determine the level of energy efficiency of industry enterprises under study.Through the example of an existing technology for the production of mineral fertilizers of one technological line with a capacity of 27.5 t/h (in terms of the finished product), the calculation of energy consumption was performed. The paper states that the modernization of the technology for the production of mineral fertilizers through the utilization of thermal SERs emitted into the environment would reduce the energy consumption of the technology by 6.33%.The mathematical model used in the study makes it possible to determine the values of energy consumption of technologies in the mineral fertilizer production industry with the greatest accuracy. The analysis of the data obtained shows that the studied technologies of the industry are characterized by irrational consumption of fuel and energy resources and, therefore, need a more thorough and systematic approach in determining energy saving reserves and ways to rationalize them in the energy technology system (ETS).

Deep neural operator-driven real-time inference to enable digital twin solutions for nuclear energy systems

This paper focuses on the feasibility of deep neural operator network (DeepONet) as a robust surrogate modeling method within the context of digital twin (DT) enabling technology for nuclear energy systems. Machine learning (ML)-based prediction algorithms that need extensive retraining for new reactor operational conditions may prohibit real-time inference for DT across varying scenarios. In this study, DeepONet is trained with possible operational conditions and that relaxes the requirement of continuous retraining - making it suitable for online and real-time prediction components for DT. Through benchmarking and evaluation, DeepONet exhibits remarkable prediction accuracy and speed, outperforming traditional ML methods, making it a suitable algorithm for real-time DT inference in solving a challenging particle transport problem. DeepONet also exhibits generalizability and computational efficiency as an efficient surrogate tool for DT component. However, the application of DeepONet reveals challenges related to optimal sensor placement and model evaluation, critical aspects of real-world DT implementation. Addressing these challenges will further enhance the method’s practicality and reliability. Overall, this study marks an important step towards harnessing the power of DeepONet surrogate modeling for real-time inference capability within the context of DT enabling technology for nuclear systems.

Decentralized Energy Systems and Blockchain Technology: Implications for Alleviating Energy Poverty

Decentralized Energy Systems and Blockchain Technology: Implications for Alleviating Energy Poverty

Energizing eutectic salt hydrate phase change material using 2D carbon based graphene nanoparticle

Energy being the strongly depended source for development and industrialization, their storage in any form tends to bridge the gap between demand and supply. Renewable energy technology systems now include energy storage as a crucial component. Thermal energy storage is a technique that stores thermal energy by heating or cooling a storage medium. This allows the energy to be used for heating and cooling purposes later on. The present study develops ternary inorganic salt hydrate eutectic phase change material (EPCM) that is intended for cooling buildings. Melting temperature, melting enthalpy and eutectic composition proportion of inorganic salt hydrate of sodium carbonate decahydrate (SCD), sodium phosphate dibasic dodecahydrate (SPDD), and sodium sulphate decahydrate (SSD) are determined using the eutectic melting point theory. Ternary EPCM is synthesised experimentally in accordance with the percentage of salt hydrates. Graphene nanoplatelets are distributed at different weight concentrations of 0.3%, 0.6%, and 0.9% in order to further improve the thermal performance; at higher concentration above 0.9% the graphene nanoplatelets tends to agglomerate. In order to assess the chemical stability and thermal properties of prepared nanoparticle dispersed PCMs, are experimentally assessed. Findings confirm the ternary EPCM's chemical stability and raise its latent heat with graphene nanoplatelets.

Beyond fixed-speed pumped storage: A comprehensive evaluation of different flexible pumped storage technologies in energy systems

Traditional fixed-speed pumped storage (PS) has been a reliable measure to provide power system flexibility. However, the increasing need for flexibility of power systems due to adverse environmental events and amplified utilization of renewable sources necessitates the need for modernization of PS units. This paper studies the effect of five PS technologies with different operational flexibility in Qinghai Province's energy system. Firstly, PS models considering the difference in minimum stable generation & pumping, unit efficiency, configurations of turbine & pump are established. Then, the energy mixes, planning capacity, inflow, reservoir operation curve and other data are input into the energy system model. Finally, we quantify the effects of different PS forms on the energy system based on technical, economic, and emission indicators, also identify the optimal PS considering cost preference and emission preference. Results show that the investment costs for various pumped storage technologies depend on the motor type and pump capacity. Fixed-speed pump turbine technologies have a lower cumulative power variation of up to 11,225 GWh and the largest number of start-ups in pumping conditions, at 10,857 times. Increasing operational flexibility stabilizes the reservoir water level, and enhancing pump capacity reduces net load fluctuations for ternary PS and variable-speed quaternary PS. Improving wind-solar curtailment is limited by pump capacity, generating flexibility, and reservoir water level. Systems equipped with fixed-speed PS technologies emit more than carbon emissions other PS technologies. Our research outcomes have the potential to provide valuable insights, enabling stakeholders to optimize the deployment of pumped storage flexibility in low-carbon energy systems, taking into account the energy mix and hydrological conditions that are specific to each region.

Preface

Proceedings 1st International Conference on Intelligent and Sustainable Power and Energy Systems (ICISPES 2023) 26 - 27 September, 2023 About the Conference The “1st International Conference on Intelligent and Sustainable Power and Energy Systems (ICISPES 2023)” is aimed to address the state-of-the-art multidisciplinary research needs and interdisciplinary aspects of intelligent and sustainable technologies in power and energy systems in the form of research papers from industry, faculty, research scholars, and PG/UG students, along with keynote lectures and a number of invited talks from reputed speakers. The ICISPES 2023 aims to provide a platform to present their work to share experiences and ideas in the areas of Renewable Energy, Electric Transportation, Power Electronics, Electric Drives, Control Techniques, Smart Grids, Communication Protocols, Intelligent Charging Infrastructure and Standards, machine learning, artificial intelligence, big data analytics, IoT, etc. In view of the changing scenario under intelligent and sustainable power and energy, this conference aims to put together the experts from these areas to disseminate their knowledge and experience for working in years to come.The ICISPES provides an international platform for all research scholars, practitioners, academicians, students and scientists to discuss and exhibit the latest research developments and discoveries in intelligent and sustainable technologies. This conference enables us to share and exchange research knowledge and ideas in power and energy systems. About the Institution Dayananda Sagar College of Engineering is approved by the All-India Council for Technical Education (AICTE), Govt. of India and affiliated to Visvesvaraya Technological University, Belgaum, Karnataka. It has the widest choice of Engineering branches, having 20 undergraduate courses and 06 postgraduate courses. In addition, it has 20 research centres in different branches of Engineering catering to research scholars for obtaining a PhD under VTU. Various courses are accredited by the NBA. The Institute is spread over 23 acres of land with a requisite infrastructure supported by laboratories with state-of-the-art equipment and machines. The central library, with modern facilities and a digital library, provides the knowledge base for the students. The college has good faculty strength with the highest professional integrity and commitment to academics with transparency in their actions. The faculty members are research-oriented, having a number of sponsored R&D projects from different agencies such as the Department of Science & Technology, Defense R&D organizations, Indian Space Research Organization, AICTE, etc.List of Speakers, Organizing Committee is available in this Pdf.

Integrating artificial intelligence and sustainable technologies in strategic renewable energy and Power-to-X projects: A review of global best practices, risks and future prospects

AbstractThe objective of this paper is to review the academic literature and identify best practices on the integration of artificial intelligence and sustainable technologies in strategic renewable energy and Power-to-X projects globally. We reflect upon the way in which exemplary case studies can be used to foster a common shared view among different policy makers to highlight new ways through which energy efficiency and systemic improvements in the energy sector may be achieved while curbing carbon emissions and addressing climate change. The main risks, challenges and mitigations for integrating artificial intelligence and sustainable technologies in energy systems are also educed from both the academic literature as well as interviews with experts. Our findings indicate that while the integration of artificial intelligence and sustainable technologies can support energy efficiency and systemic improvements in the energy sector, there are several risks that were not previously identified in the literature. Critical areas of future development for academic research as well as opportunities for professional practice are presented.

The potential of demand response as a tool for decarbonization in the energy transition

Planning and managing energy production, transmission, and distribution face new challenges as renewable energy sources become more widely used. These sources enhance existing issues of grid operation due to their unpredictability and intermittency. As a result, sophisticated energy system control techniques and technologies that offer novel flexibility solutions to the inelastic demand side are necessary to ensure the power system’s stability. This paper reviews the feasibility of demand response as a tool for effective grid management and a measure for properly sized renewable energy systems (RES) capacities, both of which could accelerate the phase-out of fossil fuels. Research also focuses on tapping into the building stock's demand response capacity in an effort to decrease operational CO2 emissions. In this line of approach, current status and goals of the respective European policies are analyzed. The role of market based decarbonization is studied and presented along with the status of demand response market implementation in several countries.

(Invited) Regenerative Fuel Cell System Utilizing a High Differential Pressure Water Electrolysis Technology

The expansion of manned activities in space requires energy system technology that utilizes sunlight, and hydrogen fuel cells are one such means. By electrolyzing water with sunlight, energy is stored with oxygen and hydrogen, and electricity is generated by fuel cells. The generated water can be recycled, and energy can be stored and supplied without external replenishment. This is commonly called a regenerative fuel cell. In the space domain, such energy systems must be compact and lightweight, and gas must be stored under high pressure. However, mechanical compressors that are generally used for compressing are heavy, and there are also issues of vibration and noise.Since the 1990s, Honda has worked on the development of high-differential-pressure water electrolysis technology that generate hydrogen from renewable energy and compress without a mechanical compressor, in parallel with the development of fuel cell technology. High-differential-pressure water electrolysis is a technology that generates high pressure hydrogen by moving the protons generated by electrolysis to the cathode through the Proton exchange membrane (PEM) . The energy required is only the potential generated by the difference in hydrogen concentration, which is superior to small mechanical compressors whose efficiency is reduced by friction loss. However, a large differential pressure is generated across the PEM because only one side is at a high pressure. Honda has achieved a maximum pressure increase of 70 MPa by using its own structure. Moreover, this principle can be applied not only to the generation and pressurization of hydrogen, but also to oxygen. Honda is working on the development of RFC technology that integrates these hydrogen technologies with the aim of applying them not only to sustainability on Earth, but also to the space domain. Currently, we are undertaking a JAXA project and are promoting the production of a breadboard model.The feature of Honda's RFC technology is that it applies high-differential-pressure water electrolysis technology, not only to generate oxygen and hydrogen, but also to pressurize each gas. By not using a mechanical compressor, it is possible to downsize the system, and it is also no vibration or noise. Utilizing the characteristics of this technology, we are planning to build an energy system that can store energy at high density and apply it to various manned missions.Honda's RFC consists of the high-differential-pressure water electrolysis system that simultaneously electrolyzes water and pressurizes oxygen, a Electrochemical hydrogen compressor system (EHC system) that electrochemically pressurizes the hydrogen and a fuel cell system. In the electrolysis stack, oxygen is generated and compressed to the target pressure by the differential pressure water electrolysis. The generated hydrogen is sent to the EHC stack that also applies the technology of high-differential pressure water electrolysis, where the hydrogen is pressurized. As a result, both oxygen and hydrogen gases were generated and compressed without a mechanical compressor. For the fuel cell system, the compact and highly efficient fuel cell technology that has been developed for FCVs is applied. When the fuel cell is used on the ground, oxygen is supplied from the atmosphere, but in space RFC it is necessary to generate electricity using pure oxygen and to circulate the system. A dedicated circulating FC system was constructed to achieve stable power generation. The water produced by power generation is used in the next water electrolysis cycle, and the proof of principle as RFC has been completed. In addition to these basic functions, for space application, we must address issues not found on Earth, such as heat management in a vacuum, radiation, and vibrations during launch. Starting with the lunar exploration mission scheduled for 2030, Honda will develop this technology for the spread of manned activities. Figure 1

Smart investigation of artificial intelligence in renewable energy system technologies by natural language processing: Insightful pattern for decision-makers

This study aims to provide a framework which enables decision-makers and researchers to identify AI technology patterns in renewable energy systems from a massive data set of textual data. However, the study was challenged by the Scopus database limitation that allows users to retrieve only 2000 documents per query. Therefore, we developed a search engine based on the Scopus Application Programming Interface (API) that enables us to download an unlimited number of documents per query based on our desirable settings. We extracted 5661 renewable energy systems-related publications from Scopus database and leveraged Natural Language Processing (NLP) and unsupervised algorithms to identify the most frequent computational science models and dense meta-topics and investigate their evolution throughout the period 2000-2021. Our findings showed 7 meta-topics based on the class-based Term Frequency-Inverse Document Frequency (c-TD-IDF) score and term score decline graph. Emerging advanced algorithms, such as different deep learning architectures, directly impacted growing meta-topics involving problems with uncertainty and dynamic conditions.

Preface

This Proceedings contains the selected papers of the 2023 3rd International Conference on Energy Engineering, New Energy Materials and Devices (NEMD 2023), which was held via virtual form in Guangzhou, China from March 24th to 26th, 2023.NEMD 2023 is aimed at the academic and scientific community and the productive sectors of the region, with the aim of disseminating academic and research work; moreover, promotes the exchange of experiences between researchers as well as the participation of the productive sectors in research, extension, technological development, and innovation activities, contributing to the strengthening the relationship between universities, enterprises and institutions.This Conference was articulated with different topics around the themes of Energy Engineering, New Energy Materials and Devices to discuss on the research findings, their possibilities and challenges. The relevance of the NEMD 2023 conference theme to a wide range of disciplines is reflected in the papers that have been submitted for publication. The topics covered in the Proceedings includes: Solar Photovoltaic Power Generation System, Principle and Technology of Solar Cell, Distributed Energy System Technology, Energy Conversion and Application, Green Energy Materials, etc.. All the papers, being reviewed through a double-blind review process, are original contributions to the topics and shown the research works that are doing in the field of the described theme.We had about 60 participants all around the world. The scientific program of the Conference was composed of keynote speech, oral presentation, and academic investigation. Assoc. Prof. Jing Guo from Xi’an Jiaotong University, China, who has published more than 80 academic publications, over 4600 SCI citations, with an H-factor of 40 (Google Academic), made a keynote speech on Ceramic-Polymer Composites Prepared via Cold Sintering Process. Ceramicpolymer composites have attracted much attention due to the excellent combined physical and chemical properties. However, most of the ceramics are sintered at high temperatures, typically higher than 1000 °C, which are not compatible with the processing temperatures of polymers. Thus, it is challenging to integrate ceramics with polymers in a onestep sintering process. Cold sintering process proposed in 2016 provides a route for the densification of ceramics at temperatures lower than 350 °C. He discussed the recent development of cold sintered electronic materials based on ceramic-polymer composites. The brilliant speeches of each speaker provided a feast of knowledge for all the participants, allowing them to communicate with each other and get some academic advice or suggestion.Our sincere thanks and gratitude to all the participants for making such a comprehensive NEMD Conference and Proceedings, which contribute to the enhancement and development in related fields. We are grateful to the Technical Program Committee for their valuable time and advice. Special thanks to the members of the Journal of Physics: Conference Series for making this Proceedings published. We appreciate the effort from those involved and look forward to a more successful conference next year.The Committee of NEMD 2023Committee Member are available in the pdf

Improving energy efficiency of ground thermal energy systems by reducing drag inside pipes

AbstractAt specified depths, ground temperature remains almost constant at 15°C, above atmospheric temperatures in winter and below those in summer. Ground thermal energy systems technology circulates water or brine through a heat‐collection tube buried underground and uses the ground thermal energy for air conditioning. However, depending on the facility, the total length of the heat‐collection tube can be several hundred meters. As a result, the pump can require significant electric power. In this study, we adopted a drag‐reduction technique using a cationic surfactant and a counter‐ion system. The optimal addition conditions of additives were investigated with a laboratory‐grade device. We also investigated corrosion inhibitors that do not interfere with the drag‐reduction effect. According to demonstration tests using practical ground thermal energy systems at two locations in Japan, we found that pump power consumption could be reduced by 10%–20% with suitable additive conditions.