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Climate change as a matter had little attention of public debate, especially in developing countries, until the recent floods caused by the dragon storms in the Middle East and the forest fires in the Mediterranean. Egypt, being strategically crucial in Africa, the Mediterranean, and the Arab world, with strong connections to other countries, aimed to go from promises to action and to discover real answers to climate change by building on past COPs. The administration assumed a more prominent role by coordinating the 27th Conference of the Parties to the United Nations Framework Convention on Climate Change (COP27). People started to realize that this is not something only happening elsewhere in the world. Egypt took the initiative; Challenges have been assessed to reach suitable mitigation approaches, and Egypt's first NDC has been issued to meet the global agenda. Egypt's vision was to accelerate global climate action at the UNFCCC 27th Conference of the Parties (COP 27) through emissions reduction, advanced adaptation, and enhanced flow of appropriate finance, prioritizing developing countries worldwide.

Abstract Nickel nanoparticles supported by commercial carbon paper (CP) are prepared by pulsed laser deposition with deposition time of 3, 6, and 12 min as a catalyst for urea electro-oxidation. The surface conditions and the morphologies of the prepared electrodes have been characterized by Raman spectroscopy, scanning electron microscopy, and transmission electron microscopy. Urea electro-oxidation reaction in KOH solution on the Ni/CP electrodes is investigated by cyclic voltammetry and chronoamperometry. The results show that the electrode with less Ni nanoparticle agglomeration shows higher peak current density, which was achieved in the 3 min deposition samples when normalized by electroactive surface areas. However, the highest current normalized by the area of the carbon paper was achieved in the 6 min deposition sample due to the larger quantity of Ni nanoparticles. All the samples show good stability. Our results suggest that the low density, low cost, and environmental friendly CP can be used as support for Ni nanoparticle as a catalyst for urea electro-oxidation. It thus has great potential for many applications involving urea oxidation, such as wastewater treatments.

Carbon is a wonder material and has served the mankind since the inception of civilization in a variety of ways. Among its different forms, carbon fibers are especially known for their conductivity and favorable strength to weight ratio. Here the development of PAN based carbon fibers embedded in a matrix material followed by pyrolysis to form a fibrous C/C composite has been discussed. The processing of carbon paper has been divided into four steps, with the product of each stage used separately for different energy applications. (1) Carbon fiber preform has been used as a filler to achieve high strength in bipolar plates for PEM Fuel cells (energy conversion). Flexural strength of nearly 80 MPa has been achieved as compared to 40 MPa of the commercially available Schunk plate, Germany. (2) Resin impregnated preform, i.e. the Green composite paper has been employed as an energy efficient heating element (energy conservation). This has been further fabricated as a room heater, which works at 500 cycles). The (4) Graphitized carbon paper has proved to be an excellent electrode (anode and cathode) backing material for PEM Fuel cell. 25% hike in the peak power density of unit PEM FC has been achieved while employing CNT incorporated NPL carbon paper as compared to while using Toray carbon paper of Japan and tested under similar conditions. This in turn is attributed to the unique properties acquired by the material with subsequent processing at each stage which has been discussed in detail. Keywords: Carbon fiber, Porosity, Microstructure, Fuel cell, Li-ion battery, Heating element

Abstract In this study, three-type paper supercapacitors based on the polyvinylidene fluoride (PVDF) and polyvinyl alcohol (PVA)/phosphoric acid (H3PO4) gel electrolytes and graphite nanoparticles (GNPs) electrodes have been fabricated. The gel electrolytes and electrodes films have been coated on the paper using push coating and then characterized by scanning electron microscopy (SEM). In two types of the paper supercapacitors, on the PVDF gel electrolyte film, a layer of PVA/water and BaTiO3 as a gel separator film has been coated. The specific capacitance of the paper supercapacitors using cyclic voltammetry (CV) and galvanostatic (charge–discharge) methods at the scan rates 20 and 150 mV s−1 have been investigated. The paper supercapacitor based on the BaTiO3 separator film showed higher specific capacitance (312 F g−1) compared to other samples. Also, using electrochemical impedance spectroscopy (EIS), the Nyquist and Bode curves of paper supercapacitors have been measured. For the paper supercapacitors based on the PVDF gel electrolyte film and BaTiO3 separator film using the Nyquist curves, the equivalent series resistance (ESR) was 306 Ω and 125 Ω, respectively. The paper supercapacitor based on BaTiO3 gel separator structure represents a new type of flexible supercapacitor with high performance that can be applied to electronic devices.

Human activity uses longest energy source is Biomass The organic waste and industrial waste water undergoes anaerobic digestion process produces biogas which is pure and nature friendly. This paper investigates production of biogas and electricity from water hyacinth. It is worlds highly unfavorable aquatic weed as it forms on water surface un traversable floating mats. This plant is suspended on water surface as the carbon to nitrogen ration of the plant is high it can be used for biogas production. Biogas mainly contains sixty per cent of methane. This present paper based on methane which is used as fuel for running IC engine and from that electricity can be generated. Biogas plant working model is studied and an evaluation of performance is done with respect to economy as an alternative fuel. Also the briquette making machine was developed from the waste which is obtained from biogas plant.

This paper explores the key aspects of battery technology, focusing on Li-ion, Lead-acid, and Nickel Metal Hydride (NiMH) batteries. It delves into manufacturing processes and highlighting their significance in optimizing battery performance. In addition, the study investigates battery fault detection, emphasizing the importance of early diagnosis using artificial intellignece (AI) and machine learning (ML) methods. This paper also addresses battery recycling techniques, discussing methods such as pyrometallurgy, hydrometallurgy, mechanical separation, and electrodialysis, considering their environmental impact. This comprehensive analysis sheds light on the evolution of battery technology and its role in sustainable energy systems.

Summary Due to the convenience of virtualization, the live migration of virtual machines is widely used to fulfill optimization objectives in cloud/edge computing. However, live migration may lead to side effects and performance degradation when migration is overused or an unreasonable migration process is carried out. One pressing challenge is how to capture the best opportunity for virtual machine migration. Leveraging rough sets and AI, this paper provides an innovative strategy based on Q-learning that is designed for migration decisions. The highlight of our strategy is the harmonious mechanism for applying rough sets and Q-learning. For the ABDS (adaptive boundary decision system) strategy in this paper, the exploration space of Q learning is confined by the boundary region of rough sets, while the thresholds of the boundary region can be dynamically adjusted by the reaction results from the computing cluster. The structure and mechanism of the ABDS strategy are described in this paper. The corresponding experiments show a firm advantage for the cooperation of rough sets and reinforcement learning algorithms. Considering both the energy consumption and application performance, the ABDS strategy in this paper outperforms the benchmark strategies in comprehensive performance.

This article introduces the concept of load aggregation, which involves a comprehensive analysis of loads to acquire their external characteristics for the purpose of modeling and analyzing power systems. The online identification method is a computer-involved approach for data collection, processing, and system identification, commonly used for adaptive control and prediction. This paper proposes a method for dynamically aggregating large-scale adjustable loads to support high proportions of new energy integration, aiming to study the aggregation characteristics of regional large-scale adjustable loads using online identification techniques and feature extraction methods. The experiment selected 300 central air conditioners as the research subject and analyzed their regulation characteristics, economic efficiency, and comfort. The experimental results show that as the adjustment time of the air conditioner increases from 5 minutes to 35 minutes, the stable adjustment quantity during the adjustment period decreases from 28.46 to 3.57, indicating that air conditioning loads can be controlled over a long period and have better adjustment effects in the short term. Overall, the experimental results of this paper demonstrate that analyzing the aggregation characteristics of regional large-scale adjustable loads using online identification techniques and feature extraction algorithms is effective.

Abstract The IPT system has been studied for underwater applications such as autonomous underwater vehicles (AUVs) and subsea sensors. However, it rarely comparatively shows the performance of the IPT system in air, freshwater, and seawater. Based on the fore‐mentioned research background, this paper presents a survey of the properties of the IPT system in different mediums. Here, a 100 W power‐level experimental IPT prototype is built and tested. The resonant frequency is set at 300 kHz with a gap range from 10 to 190 mm. The comparison is focused on the efficiency, mutual inductance, coupling coefficient, coil resistance, and quality factor of the IPT system. The IPT system is placed in air, freshwater, and seawater with the same settings. What's more, the magnetic fields of coupling coils in air, freshwater, and seawater are presented in this paper. This paper could be acted as a reference to optimize the IPT system and facilitate future IPT research for underwater applications by analysing the performance of the IPT system in different mediums. The 3D Ansys Maxwell simulation of the IPT system is also given here to study the magnetic fields.

The South African downstream petroleum industry was in the hands of Whites and Multinational Oil Companies during the apartheid era. Many Historically Disadvantaged South Africans (HDSA’s) were excluded from the mainstream industry through, among other instruments, laws passed by the government such as the Petroleum Products Act 120 of 1977. Against this background, the newly elected democratic government instituted a policy process aimed at restructuring and transforming the petroleum industry to allow HDSA’s to enter the industry, in order to achieve sustainable presence, ownership and control of approximately a quarter of the industry by previously disadvantaged individuals. Since the introduction of this process, which culminated in the release of the White Paper on the Energy Policy of the Republic of South Africa (1998), little progress has been made towards achieving this government’s key policy objective. Instead, there is still little entry into the industry by HDSA’s, and the Black Oil Companies (BOC’s) that are in the industry continue to struggle to increase their market share. This paper discusses the possible constraints on achieving the objective, by looking at barriers that impede HDSA’s from entering the industry and BOC’s from increasing their market share significantly. There are three possible categories of barriers in the downstream petroleum industry, namely, economic barriers to entry, noneconomic barriers, and cross-sectoral barriers to entry, which are discussed in this paper. These categories of barriers prevent entry by HDSA’s into the industry and hinder BOC’s from increasing their market share. To circumvent these barriers, and in order to make progress towards achieving the government’s key policy objective of control by approximately a quarter of the HDSA’s, a black economic empowerment model was developed. This model seeks to increase the market share of the BOC’s and the presence of the HDSA’s in the industry in a sustainable way without significantly harming the multinational oil companies. It foresees Government licensing BOC’s to purchase up to 5% of the existing South African fuel demand at an Import Parity Price (IPP) that is significantly less than the Basic Fuel Price (BFP). The reason for this difference is that the BFP is based upon the supply of the totality of South Africa’s needs from elsewhere, whereas the IPP merely supplies up to 5% of South Africa’s needs, and can therefore source the product from refineries that are closer, so reducing the transport component. The impact of the loss of 5% of the internal market for petrol and diesel on the revenues of the MOC’s is less than 0.5%, because the difference between the IPP and BFP is a small fraction of the BFP.

As the world addresses the increasing demand for sustainable energy solutions, biodiesel has surfaced as a viable alternative to conventional fossil fuels. The expansion of biodiesel feedstock plantations, particularly palm oil in tropical regions, can lead to deforestation, loss of biodiversity, and significant carbon emissions from the destruction of carbon-rich ecosystems. That is why this article focuses on biodiesel production from waste sources in order to maintain balance in the ecosystem. This review paper discusses the global energy landscape and the need for renewable and environmentally friendly alternatives. It explores the various waste sources in depth that are investigated for biodiesel production, comprising waste cooking oil, animal fats, algae, and other organic residues. Each feedstock is analyzed for its viability, challenges, and economic feasibility in biodiesel production. A critical assessment of different biodiesel production methods, such as transesterification, pyrolysis, thermochemical conversion, anaerobic digestion, thermal cracking, hydro-treating and enzymatic processes, is presented, highlighting the key factors influencing their efficiency and scalability. Recent developments to enhance waste-derived biodiesel production’s sustainability and economic viability to meet UN Sustainable Development Goals are also highlighted. Furthermore, the environmental impact of biodiesel, including greenhouse gas emissions and land use, is discussed to provide a holistic understanding of its ecological footprint. The biodiesel from waste sources can significantly increase the brake thermal efficiency of the engine along with a substantial decrease in emissions like CO and HC. However, the NOx and CO2 emissions are increased with the application of biodiesel from waste sources. The CO2 and NOx emissions can be reduced by exhaust gas recirculation and selective catalytic reduction techniques. The paper also addresses regulatory frameworks and standards governing biodiesel production from waste sources, emphasizing the need for harmonized policies to encourage widespread adoption. The paper concludes by outlining future research directions and potential breakthroughs that could further enhance biodiesel production’s effectiveness, sustainability, and scalability from waste sources. Waste Cooking Oil (WCO) and animal fats are currently the most economically feasible options for biodiesel production due to their low cost and established collection and processing infrastructure. Algae present high potential but require technological advancements and cost reductions to become economically viable. This review aims to assist researchers, policymakers, and industry stakeholders in advancing the utilization of waste materials for biodiesel production, promoting a more sustainable energy landscape.

The speed regulation technology for energy conservation of pump and fan systems occupies an important position in industrial field. The paper focuses on the rapid development and research significance of speed regulation technology for energy conservation based on different permanent magnet adjustable speed drives (PMASDs). The development history and speed regulation scheme for energy conservation are introduced step by step. The features of theoretical model based on magnetic vector potential and equivalent magnetic circuit methods are presented and studied in the paper, which is benefit to select a suitable method for a specific drive. Several optimization methods of design parameters of PMASDs are given in the paper. The structure and operating principle of some new speed regulation scheme are described, and their advantages, disadvantages and feasibility of engineering application are analyzed. Finally, the proposed speed regulation technologies for energy conservation are summarized and classified from the aspects of magnetic circuit structure, permanent magnet rotor structure, conductor rotor structure, and the slip power conversion scheme. In a conclusion, the power-fed PMASD will be the future of energy conservation technology for the high-efficiency and low-cost large pump and fan systems.

In light of the growing integration of renewable energy sources in power systems, the adoption of DC microgrids has become increasingly popular, due to its simple structure, having no frequency, power factor concerns. However, the dependence of DC microgrids on cyber-networks also makes them susceptible to cyber-attacks. Potential cyber- attacks can disrupt power system facilities and result in significant economic and loss of life. To address this concern, this paper presents an attack-resilient control strategy for microgrids to ensure voltage regulation and power sharing with stable operation under cyber-attack on the actuators. This paper first formulates the cyber-security problem considering a distributed generation based microgrid using the converter model, after which an attack-resilient control is proposed to eliminate the actuator attack impact on the system. Steady state analysis and root locus validation illustrate the feasibility of the proposed method. The effectiveness of the proposed control scheme is demonstrated through simulation results.

Transdisciplinary research has gained traction globally for mapping pathways for sustainable urbanisation. The involvement of local communities is believed to central to knowledge co-production needed to address sustainability challenges. But working with local communities can be challenging. This paper is structured around the authors’ personal reflections on undertaking transdisciplinary household energy conservation projects in Ghana and South Africa. The paper reflects on the assumptions and challenges of doing transdisciplinary research in urban Africa and suggests some guidelines for consideration when doing transdisciplinary projects. An inductive analysis of our reflections showed five key challenges: lack of integration, divergent problem identification, tensions in knowledge co-production, asymmetrical power relations, and distrust and managing expectations. We draw on our collective experiences to develop guidelines for conducting transdisciplinary research in urban Africa. These guidelines are not prescriptive but can be useful for a growing and broader audience interested in undertaking transdisciplinary research.

This work investigates the interaction between water waves and multiple ice shelf fragments in front of a semi-infinite ice sheet. The hydrodynamics are modelled using shallow water wave theory and the ice shelf vibration is modelled using Euler–Bernoulli beam theory. The ensuing multiple scattering problem is solved in the frequency domain using the transfer matrix method. The appropriate conservation of energy identity is derived in order to validate our numerical calculations. The transient scattering problem for incident wave packets is constructed from the frequency domain solutions. By incorporating multiple scattering, this paper extends previous models that have only considered a continuous semi-infinite ice shelf. This paper serves as a fundamental step towards developing a comprehensive model to simulate the breakup of ice shelves.

Due to the rapid development of the space industry, ever higher demands are being made for the optimization and improvement of spacecraft thermal management systems. Thermal control technology has become one of the key bottlenecks that restrict the level of spacecraft design. In this paper, the thermal management technologies (TMTs) for spacecraft electronics are reviewed according to the different heat transfer processes, including heat acquisition, heat transport, and heat rejection. The researches on efficient heat acquisition include the utilization of high thermal conductance materials, the development of novel package structure based on micro-/nano-electromechanical system (MEMS/NEMS) technologies, and advanced near-junction microfluidic cooling techniques. For the heat transport process, various heat pipes and mechanical pumped fluid loops (MPFLs) are widely implemented to transport heat from heat generation components to the ultimate heat sinks. The heat pipes are divided into two categories based on their structure layout, i.e., separated heat pipes and unseparated heat pipes. The merits and demerits of these heat pipes and MPFLs (including the single-phase MPFL and the two-phase MPFL) are discussed and summarized respectively. In terms of the heat rejection for spacecraft, thermal radiators are normally the sole option due to the unique space environment. To meet the requirements of large heat dissipation power and fluctuated thermal environment, research efforts on the radiators mainly focus on the development of deployable radiators, variable emissivity radiators, and the combination with other techniques. Due to the fluctuated characteristics of the heat power of internal electronics and the outer thermal environment, the phase change materials (PCMs) exhibit great advantages in this scenario and have attracted a lot of research attention. This review aims to serve as a reference guide for the development of thermal management system in the future spacecraft.

This paper presents a novel approach that simultaneously enables photovoltaic (PV) inversion and flexible arc suppression during single-phase grounding faults. Inverters compensate for ground currents through an arc-elimination function, while outputting a PV direct current (DC) power supply. This method effectively reduces the residual grounding current. To reduce the dependence of the arc-suppression performance on accurate compensation current-injection models, an adaptive fuzzy neural network imitating a sliding mode controller was designed. An online adaptive adjustment law for network parameters was developed, based on the Lyapunov stability theorem, to improve the robustness of the inverter to fault and connection locations. Furthermore, a new arc-suppression control exit strategy is proposed to allow a zero- sequence voltage amplitude to quickly and smoothly track a target value by controlling the nonlinear decrease in current and reducing the regulation time. Simulation results showed that the proposed method can effectively achieve fast arc suppression and reduce the fault impact current in single-phase grounding faults. Compared to other methods, the proposed method can generate a lower residual grounding current and maintain good arc-suppression performance under different transition resistances and fault locations.

Hydrogen production by proton exchange membrane electrolysis has good fluctuation adaptability, making it suitable for hydrogen production by electrolysis in fluctuating power sources such as wind power. However, current research on the durability of proton exchange membrane electrolyzers is insufficient. Studying the typical operating conditions of wind power electrolysis for hydrogen production can provide boundary conditions for performance and degradation tests of electrolysis stacks. In this study, the operating condition spectrum of an electrolysis stack degradation test cycle was proposed. Based on the rate of change of the wind farm output power and the time-averaged peak-valley difference, a fluctuation output power sample set was formed. The characteristic quantities that played an important role in the degradation of the electrolysis stack were selected. Dimensionality reduction of the operating data was performed using principal component analysis. Clustering analysis of the data segments was completed using an improved Gaussian mixture clustering algorithm. Taking the annual output power data of wind farms in Northwest China with a sampling rate of 1 min as an example, the cyclic operating condition spectrum of the proton-exchange membrane electrolysis stack degradation test was constructed. After preliminary simulation analysis, the typical operating condition proposed in this paper effectively reflects the impact of the original curve on the performance degradation of the electrolysis stack. This study provides a method for evaluating the degradation characteristics and system efficiency of an electrolysis stack due to fluctuations in renewable energy.

In this paper, we study a hydrodynamic system modeling the evolution of a plasma subject to a self-induced electromagnetic Lorentz force in incompressible viscous fluids. The system consists of the Navier–Stokes equations coupled with a Maxwell equation. In the three dimensional case, we show that every weak solution verifies the energy equality for the incompressible Navier–Stokes–Maxwell equations with damping. We also establish some non-explosion criteria in terms of the velocity and magnetic of local strong solution for standard Navier–Stokes–Maxwell system.

This paper studies the dynamics and conservation of energy. It evaluates the validity of Noether's theorem as a formal argument supporting the law of conservation of energy in physical systems. The analysis examines the role of nonconvexity in energy dynamics. The paper argues that nonconvexity can arise in the presence of catalytic effects or in situations of transitions between multiple regimes. With the introduction of nonconvexity, the analysis relies on a generalized Lagrangian and generalized Hamiltonian. The investigation applies under general conditions, allowing for multiple types of energy with dynamics driven by multiple state variables. Our key result is to show that the conservation of energy (Noether's theorem) holds under convexity but not under nonconvexity. This identifies situations where energy in isolated systems is not necessarily constant over time. By relaxing the law of conservation of energy, our analysis provides new insights into energy dynamics. It offers new directions for scientific inquiries, including improved understanding about the origin of life, the evolution of the early universe and the nature of space and time.

In order to reveal the impact of fracturing fluid retention and flowback on the development effect after large-scale fracturing in shale oil wells, and to formulate a reasonable flowback policy, this paper employs a combination of core physical simulation experiments and theoretical analysis. We have designed a specially designed device that can evaluate the development effect of quasi-natural energy in oil reservoirs. The impact of fracturing fluid retention on development is simulated by changing the amount of fracturing fluid injected into the formation in a fractured horizontal well model (referred as injection volume), and the impact on development effect is analyzed by changing the properties of fracturing fluid to adjust the difference in the degree of flowback. Based on the experimental results, the mechanism of fracturing fluid retention and flowback after large-scale fracturing in shale reservoirs is further explored. The results of the experiments show that the flowback rate of fracturing fluid exhibits a monotonic decreasing trend with increasing the volume of injected fluid, as increasing the volume of injected fluid helps to enhance its retention in the formation and reduce the flowback rate. The degree of fracturing fluid flowback is critical to the mobility of crude oil in the tight reservoir. The entering of fracturing fluid into the reservoir slows down the rate of discharge in the fracture network, effectively extending the reach of the fracturing fluid in the tight reservoir and allowing more crude oil to be used, which in turn results in higher crude oil production. However, too much injection fluid may affect the fluid production. Simulation experiments reveal that the use of fracturing fluid retention or controlling the rate of flowback by changing the viscosity of fracturing fluid can be a way to enhance the development effect of horizontal shale oil wells. The results of this paper provide a basis for understanding the mechanism of shale oil development, exploring technical ideas to improve the development effect, and making decisions on the flowback parameters.

The escalating penetration of renewable energy, notably wind and solar, introduces unique complexities into power systems, particularly in frequency and voltage regulation. Current grid codes are inadequate for these emerging dynamics, necessitating significant enhancements to cope with the evolving energy landscape. The paper highlights several pivotal areas of improvement, including increased flexibility within power systems, integration of energy storage systems, expansion of ancillary services, the inclusion of grid-forming inverters, and the international harmonization of grid codes. The research underscores that conventional power system methodologies, primarily reliant on traditional power plants, fail to manage the fluctuating supply-demand dynamics of renewable energy effectively. By proposing improvements in grid codes, the research contributes towards resolving this issue. Furthermore, the paper underlines the paramount importance of international harmonization of grid codes for system interoperability, efficient operation, and exchange of best practices across diverse regions. Through its exhaustive exploration and recommendations, the study empowers policymakers, grid operators, and energy producers to advance grid code frameworks. Consequently, this facilitates renewable energy integration, ensures grid stability, and paves the way for a more sustainable energy future.

With the rapid development of new energy technologies, lithium batteries are widely used in the field of energy storage systems and electric vehicles. The accurate prediction for the state of health (SOH) has an important role in maintaining a safe and stable operation of lithium-ion batteries. To address the problems of uncertain battery discharge conditions and low SOH estimation accuracy in practical applications, this paper proposes a SOH estimation method based on constant-current battery charging section characteristics with a back-propagation neural network with an improved atom search optimization algorithm. A temperature characteristic, equal-time temperature variation (Dt_DT), is proposed by analyzing the temperature data of the battery charging section with the incremental capacity (IC) characteristics obtained from an IC analysis as an input to the data-driven prediction model. Testing and analysis of the proposed prediction model are carried out using publicly available datasets. Experimental results show that the maximum error of SOH estimation results for the proposed method in this paper is below 1.5%.

Solar-powered photovoltaic pumping systems (SPVPSs) have emerged as a promising solution for sustainable drip irrigation in agriculture. This review article presents recent advances in SPVPSs for drip irrigation, with a focus on their design, performance and integration. The paper provides an overview of the key components and working principles of SPVPSs. Various system configurations and optimization strategies are discussed, emphasizing the importance of system sizing, energy management and water supply efficiency. The review also addresses challenges and future directions in the field. The initial investment costs, technical constraints, and the need for capacity building are identified as key challenges to widespread adoption. However, ongoing research and development efforts are focused on cost reduction, system optimization, and policy support to overcome these challenges. Technological innovations, such as advanced control algorithms and energy storage systems, are paving the way for improved system performance and reliability. The integration of SPVPSs with drip irrigation offers environmental and socio-economic benefits. These systems contribute to reduced greenhouse gas emissions and water conservation. Moreover, they enhance agricultural productivity, income generation, and food security, particularly in off-grid and rural areas. SPVPSs for drip irrigation hold great promise for sustainable agriculture and water resource management. Continued research, collaboration, and policy support are essential to further advance these systems, address challenges, and promote their widespread adoption. This review paper provides insights for researchers, policymakers, and practitioners interested in harnessing the potential of SPVPSs for sustainable drip irrigation.

With the growing need for renewable energy, wind farms are playing an important role in generating clean power from wind resources. The best wind turbine architecture in a wind farm has a major influence on the energy extraction efficiency. This paper describes a unique strategy for optimizing wind turbine locations on a wind farm that combines the capabilities of particle swarm optimization (PSO) and artificial neural networks (ANNs). The PSO method was used to explore the solution space and develop preliminary turbine layouts, and the ANN model was used to fine- tune the placements based on the predicted energy generation. The proposed hybrid technique seeks to increase energy output while considering site-specific wind patterns and topographical limits. The efficacy and superiority of the hybrid PSO-ANN methodology are proved through comprehensive simulations and comparisons with existing approaches, giving exciting prospects for developing more efficient and sustainable wind farms. The integration of ANNs and PSO in our methodology is of paramount importance because it leverages the complementary strengths of both techniques. Furthermore, this novel methodology harnesses historical data through ANNs to identify optimal turbine positions that align with the wind speed and direction and enhance energy extraction efficiency. A notable increase in power generation is observed across various scenarios. The percentage increase in the power generation ranged from approximately 7.7% to 11.1%. Owing to its versatility and adaptability to site-specific conditions, the hybrid model offers promising prospects for advancing the field of wind farm layout optimization and contributing to a greener and more sustainable energy future.

To predict renewable energy sources such as solar power in microgrids more accurately, a hybrid power prediction method is presented in this paper. First, the self-attention mechanism is introduced based on a bidirectional gated recurrent neural network (BiGRU) to explore the time-series characteristics of solar power output and consider the influence of different time nodes on the prediction results. Subsequently, an improved quantum particle swarm optimization (QPSO) algorithm is proposed to optimize the hyperparameters of the combined prediction model. The final proposed LQPSO-BiGRU-self-attention hybrid model can predict solar power more effectively. In addition, considering the coordinated utilization of various energy sources such as electricity, hydrogen, and renewable energy, a multi-objective optimization model that considers both economic and environmental costs was constructed. A two-stage adaptive multi- objective quantum particle swarm optimization algorithm aided by a Lévy flight, named MO-LQPSO, was proposed for the comprehensive optimal scheduling of a multi-energy microgrid system. This algorithm effectively balances the global and local search capabilities and enhances the solution of complex nonlinear problems. The effectiveness and superiority of the proposed scheme are verified through comparative simulations.

Achieving a balance between accuracy and efficiency in target detection applications is an important research topic. To detect abnormal targets on power transmission lines at the power edge, this paper proposes an effective method for reducing the data bit width of the network for floating-point quantization. By performing exponent prealignment and mantissa shifting operations, this method avoids the frequent alignment operations of standard floating-point data, thereby further reducing the exponent and mantissa bit width input into the training process. This enables training low-data-bit width models with low hardware-resource consumption while maintaining accuracy. Experimental tests were conducted on a dataset of real-world images of abnormal targets on transmission lines. The results indicate that while maintaining accuracy at a basic level, the proposed method can significantly reduce the data bit width compared with single-precision data. This suggests that the proposed method has a marked ability to enhance the real-time detection of abnormal targets in transmission circuits. Furthermore, a qualitative analysis indicated that the proposed quantization method is particularly suitable for hardware architectures that integrate storage and computation and exhibit good transferability.

Abstract With the recent advances in smartphones and Internet technologies, ride‐hailing services (such as Uber and Didi) have emerged and changed the travel modes that residents use. An important issue within this area is how ride‐hailing services influence public transit usage. The majority of the research regarding this topic has focused on situations in large cities and has not reached a unanimous consensus among scholars. In particular, the role of ride‐hailing services in small‐ and medium‐sized cities may be different from the role of these services in large cities. In this paper, we choose 22 small‐ and medium‐sized cities in China as samples with a research time window spanning from 2011 to 2016 to examine the impact of the introduction of ride‐hailing services on public transit usage. The results of the synthetic control method, as well as other robustness checks, show that (1) the introduction of ride‐hailing services to China's small‐ and medium‐sized cities significantly increases public transit usage; (2) the effect of the introduction of ride‐hailing services on public transit usage in small‐ and medium‐sized cities is “proactive” for approximately 1 year; and (3) the positive effect of ride‐hailing services on public transit usage in small‐ and medium‐sized cities weakens over time. This study enriches the literature on the impact of ride‐hailing services on the urban transportation system by specifically taking small‐ and medium‐sized cities as the research scope. The above findings are of great significance to the urban transport department's formulation of ride‐hailing policies and the operation layout of public transit operators in small‐ and medium‐sized cities.

Abstract With the expansion of the metropolitan area, the application of express/local mode is gradually increasing. In contrast to the normal mode, the express/local mode has advantages in reducing energy consumption and saving total travel time by having express trains skipping some stops. This paper aims to minimize the total energy consumption of express and local train throughout the day by optimizing the train operation strategy in the same power supply section and increasing the overlap time between train traction acceleration and train regenerative braking to obtain the optimal energy‐efficient timetable. As the consumed energy of a train is highly dependent on the rolling stock weight and the on‐board passengers’ weight. An integer programming model is proposed with on‐board passengers considered accurately, in which the dwell times, departure headway, and total turnaround time of express and local trains are determined. An improved grey wolf algorithm is designed by improving convergence factor and incorporating differential evolution to solve the proposed problem. The real data on Guangzhou Metro Line 18 is adopted for numerical studies. The results show that the optimized timetable increases the regenerative energy utilization rate by 21.37% and reduces the total energy consumption by 5.02% compared to the operational timetable.

Due to its zero emissions, high efficiency and low noise, proton exchange membrane fuel cell (PEMFC) is full of potential for the application of vehicle power source. Nonetheless, its lifespan and durability remain multiple obstacles to be solved before widespread commercialization. Frequent exposure to non-rated operating conditions could considerably accelerate the degradation of the PEMFC in various forms, thus reducing its durability. This paper first analyzes degradation mechanisms of PEMFCs under typical automotive operating conditions, including idling, startup-shutdown, dynamic loads, and cold start. The corresponding accelerated stress testing methods are also discussed. Then, as the impurities existed in the reaction gas source and generated from the degradation of the PEMFC itself may occur under all automotive conditions, the degradation mechanisms caused by impurity contamination are classified and reviewed in detail. After that, the techniques proposed by researchers to enhance the durability of PEMFCs are presented from four aspects: membrane electrode assembly materials, bipolar plates and flow fields design, stack assembly, and cell control strategies. The challenges in the field and the prospects for the future are summarized and analyzed at the end. The aim of this work is to provide guidelines for improving the durability of PEMFCs in vehicle applications.

Abstract With the increasing concerns about railway energy efficiency, two typical driving strategies have been used in actual train operation. One includes a sequence of full power traction, cruising, coasting, and full braking (CC). The other uses coasting–remotoring (CR) to replace cruising in CC. However, energy‐saving performance by CC and CR, which can be affected by route parameters of gradients and speed limits, has not been fully compared and studied. This paper analyses the energy distribution of CC and CR considering various route parameters and proposes an improved strategy for different gradients and speed limits. The detailed energy flow of CC and CR is analysed by Cauchy–Bunyakovsky–Schwarz inequality and the generalised Hölder's inequality, and then, a novel driving strategy CC_CR is designed. To verify the theoretical results and the effectiveness of the proposed strategy, three simulators with CC, CR, and CC_CR driving modes have been developed and implemented into case studies of four scenarios as well as a real‐world metro line. Simulation results demonstrate that CR can only outperform CC on routes with steep downhill and CC_CR is always the best strategy. The energy savings of CC_CR can be as much as 15% more than CR and 42% greater than CC.

This paper proposes a longitudinal protection scheme utilizing empirical wavelet transform (EWT) for a through- type cophase traction direct power supply system, where both sides of a traction network line exhibit a distinctive boundary structure. This approach capitalizes on the boundary’s capacity to attenuate the high-frequency component of fault signals, resulting in a variation in the high-frequency transient energy ratio when faults occur inside or outside the line. During internal line faults, the high-frequency transient energy at the checkpoints located at both ends surpasses that of its neighboring lines. Conversely, for faults external to the line, the energy is lower compared to adjacent lines. EWT is employed to decompose the collected fault current signals, allowing access to the high-frequency transient energy. The longitudinal protection for the traction network line is established based on disparities between both ends of the traction network line and the high-frequency transient energy on either side of the boundary. Moreover, simulation verification through experimental results demonstrates the effectiveness of the proposed protection scheme across various initial fault angles, distances to faults, and fault transition resistances.

Vibration measurements can be used to evaluate the operation status of power equipment and are widely applied in equipment quality inspection and fault identification. Event-sensing technology can sense the change in surface light intensity caused by object vibration and provide a visual description of vibration behavior. Based on the analysis of the principle underlying the transformation of vibration behavior into event flow data by an event sensor, this paper proposes an algorithm to reconstruct event flow data into a relationship correlating vibration displacement and time to extract the amplitude-frequency characteristics of the vibration signal. A vibration measurement test platform is constructed, and feasibility and effectiveness tests are performed for the vibration motor and other power equipment. The results show that event-sensing technology can effectively perceive the surface vibration behavior of power and provide a wide dynamic range. Furthermore, the vibration measurement and visualization algorithm for power equipment constructed using this technology offers high measurement accuracy and efficiency. The results of this study provide a new noncontact and visual method for locating vibrations and performing amplitude-frequency analysis on power equipment.

Abstract Nowadays, addressing the drawbacks of liquid electrolyte-based batteries is a hot and challenging issue, which is supposed to be fulfilled through solid electrolyte systems such as polymer electrolytes. Polymer blend electrolytes (PBEs) are widely investigated as viable options to solve the undesired characteristics of their liquid counterparts and also the poor ionic conductivity of homopolymer-based electrolytes. Even though PBEs outperform homopolymer-based electrolytes in terms of performance, the conductivity of pristine PBEs is quite low for practical applications (i.e. below 10–3 S/cm at room temperature). A very promising approach to solve this limitation is to incorporate additives into the electrolyte systems, to select suitable polymeric materials and to employ the desired synthesizing techniques as the performance of PBEs is strongly dependent on the selection of polymeric materials (i.e. on the inherent properties of polymers), the nature and amount of salts and other additives, and also the techniques employed to synthesize the polymer blend hosts and/or polymer blend electrolytes, determining the functionality, amorphousness, dielectric constant, dimensional stability, and, ultimately, the electrochemical performances of the system. This paper reviews the different factors affecting the miscibility of polymer blends, PBEs synthesizing techniques, the thermal, chemical, mechanical and electrochemical characteristics of PBEs, and also the challenges and opportunities of PBEs. Moreover, the paper presents the current progress of polymer blend electrolytes as well as future prospects for advancing polymer blend electrolytes in the energy storage sectors.

In response to the global climate change and the need for green and low-carbon development, hydrogen energy has been recognized as a clean energy source that can achieve carbon neutrality unlike fossil fuels. As a country with a shortage of energy resources, the development of hydrogen energy is of significant importance for China to adjust its energy structure and accelerate the new era of energy transformation. Based on the development of China's hydrogen energy industry, this paper elaborates on the current status and development trends of key technologies in the entire industrial chain of hydrogen energy in various stages including production, storage, transportation, and application, and identifies the problems and challenges of hydrogen energy development. The paper focuses on the analysis of hydrogen storage and transportation application scenarios and clarifies the selection of hydrogen storage and transportation technologies in different scenarios. To achieve healthy development of China's hydrogen energy industry, it is necessary to strengthen top-level design, make strategic planning, encourage large-scale state-owned energy enterprises to play a leading role, promote the development of the entire industry chain, increase technological research and development efforts, prevent the risk of core technology constraints, and vigorously promote the application of hydrogen energy to realize the construction of a hydrogen energy society.

Portable, wearable electronic devices have spurred the rapid development of flexible and stretchable energy harvesting/storage devices with high energy density, superior mechanical stability, and long cycle life. Micro-supercapacitor (MSC) has attracted wide interest due to their advantages of high power density, rapid charge and discharge, and long cycle life. Fabrication of flexible supercapacitors based on laser induced graphene (LIG) has shown strong advantages and potential for flexible sensor power supply. The purpose of this paper is to propose and develop a laser induced flexible micro-supercapacitor (FMSC) for pressure sensors. FMSC is manufactured from a planar forked finger electrode made of graphene induced by CO2 laser radiation commercial Polyimide (PI) film and PVA polymer gel electrolyte. The FMSCs prepared by this method exhibit good electrochemical properties and excellent mechanical properties. The microscopic morphology of LIG was investigated using SEM, and the optimal laser-induced power was determined to be 12.5%. In this paper, a novel fork-finger electrode pattern was applied to improve the performance of FMSCs by optimizing the structure of planar interdigital electrodes, and the FMSCs prepared at 12.5% power showed excellent supercapacitance performance at a voltage window of 0.8 V with a specific capacitance of 2.21 mF/cm2. The FMSCs were made by assembling commercial PI films, PVA, and H3PO4 simple materials, which makes it possible to prepare FMSCs at low cost and high efficiency based on laser direct writing technology. FMSCs provide energy to the flexible sensors and continuously collect energy to charge FMSCs through an integrated flexible energy harvester, which makes FMSCs promising for flexible self-powered wireless sensing platforms.

Agricultural waste is rich in organic matter and an important secondary source of phosphorus, which can be converted into valuable products through various technologies. Composting is an effective way to treat agricultural waste and further produce organic fertilizer, achieving waste minimization and stabilization. This paper reviews the current situation of agricultural waste pollution and composting technology, introduces the parameters that influence of the composting process and the optimal conditions, and presents the indicators for evaluating the decay of compost products and the evaluation criteria as well. In the composting process, small-molecule organic acids produced by the degradation of easily degradable organic matter such as sugars and lipids and various enzymes produced by microorganisms (phytase, phosphatase, etc.) can mineralize organic phosphorus such as phytate and phospholipids, promote phosphorus activation and provide phosphorus sources for microorganisms, so the conversion of organic matter and phosphorus is related to the fertilizer effect of composted products. Therefore, the clarification of the characteristics of organic matter and phosphorus transformation in the composting process is an important prerequisite for the resource utilization of agricultural organic waste. This paper provides theoretical support for the sustainable utilization of agricultural organic waste resources.

Net zero energy building (NZEB) is an efficient approach to boost the world’s sustainable development and climate mitigation. This paper provides a comprehensive review of multi-objective optimization (MOO)-based case studies of NZEB design. The critical analysis focuses on the “3Ps” criteria of sustainability, which encompass social, environmental, and economic aspects of protecting the people, planet, and profit. This study identifies the gaps in exploring case studies based on MOO techniques for decision-making regarding NZEB design in India and its requirements. Moreover, it demonstrates various passive design strategies, energy-efficient technologies, and renewable energy, and their impact on occupant comfort, energy model, and the building life cycle. It presents the global needs and requirements of NZEB, and definitions of NZEB in different countries and their policies. This review suggests a four-step methodological framework for NZEB design in India. It provides the potential and reliability of various algorithms, tools, and simulation engines to solve building problems. The framework presented here can aid designers in the decision-making of NZEB design, refurbishment, and renovation. Moreover, this study highlights the future research direction and potential challenges for implementing the proposed framework in India.

Global DC fast-charging infrastructure is being rapidly developed to accommodate the ever-increasing demand from the electric vehicle market. A major complication in the electric power system's process is the proliferation of ultra-fast charging (UFC) stations, which are known for their enormous power consumption and unpredictable, intermittent performance. By implementing grid-supportive features and ensuring an improved power consumption profile for the grid, installing regional energy storage can solve these challenges. This study presents a control approach for managing the grid-side AC/DC converters of rapid charging stations focused on future-oriented regulation. The paper primarily concentrates on various Vienna rectifier topologies. The technology, characteristics, benefits, and operational aspects of Vienna rectifier topologies are vital to improving the performance, efficiency, and grid integration of electric vehicle charging systems. Fast charging, grid stability, energy economy, and the smooth integration of electric vehicles into the electrical grid are all made possible by Vienna rectifiers. When used in battery energy storage systems (BESS) for electric vehicle charging infrastructure, Vienna rectifiers allow for effective discharge and charging of the batteries. The configurations and assessments of these converters are examined, assessed, and compared based on power output parameters, element count, power factor, THD, and efficiency. The Vienna rectifier has been identified as the best suitable DC fast-charging converter architecture for power levels exceeding 15 kW due to its exceptional efficiency, limited output voltage ripples, high power density, reduced current ripples, and reliable performance. Research on ways to improve electric vehicle charging infrastructure can be spurred by a better grasp of the Vienna rectifier's technological complexities and performance benefits, leading to greener and more efficient transportation options. As a result, the system's power density will eventually rise and elemental stress will decrease.

The expected increase in green hydrogen demand in the near future necessitates scaling-up the hydrogen production plants with the goal of reducing the hydrogen production costs. Nevertheless, a quick scale-up limits the time to test new designs, optimize operation schedules and build up knowledge for production parameters. The Digital Twin concept applied on a fleet of electrolysers is proposed as a digitization tool to contribute to this scale-up process by providing a comprehensive view of the entire electrolysers fleet as well as constructing the feedback connection to the electrolysers manufacturing process. Such Fleet Digital Twin approach can improve the efficiency and scalability of green hydrogen production using water electrolysis. This paper presents a concept of a Fleet Digital Twin and discusses its architecture requirements and design. By applying the Digital Twin concept at different levels of the system, fleet knowledge services are enabled by leveraging the availability of fleet-wide data. The proposed architecture design provides a solid foundation for future development and implementation of Fleet Digital Twins in industrial applications.

In light of continuous advancements in science and technology, the global economy is experiencing rapid growth. However, this growth has been accompanied by significant depletion of natural resources and environmental degradation. Consequently, there is a burgeoning global emphasis on energy conservation, emissions reduction, and sustainable development. In this study, based on the Science Citation Index Expanded (SCIE) and Social Science Citation Index (SSCI) databases from 1990 to 2022, a statistical analysis of energy conservation and emission reduction in alignment with Sustainable Development Goals (SDGs)-related publications was undertaken using biblimometric methods. The findings reveal that (1) In recent years, there has been a discernible increase in global research on this subject, especially since 2009, with a sustained trend of exceeding 100 publications per annum. China prominently contributing to this domain, the proportion reached 34.2%, reflecting a growing emphasis on eco-friendly development trends. (2) Due to the burgeoning significance of energy conservation and emission reduction, there has been a notable escalation in research efforts pertaining to “Energy and Fuels,” “Environmental Science” and “Green and Sustainable Science and Technology” and other related subjects. (3) Regarding the keyword analysis, “renewable energy” as the most frequently encountered term, often paired with “CO2 emissions.” This association underscores the pivotal role of renewable energy technologies in advancing green development initiatives and mitigating emissions. (4) China, United States and United Kingdom occupy central positions in terms of both paper publication volume and collaborative networks, collectively accounting for about 54.7%, and these countries are pivotal contributors to the scholarly discourse on sustainable development and environmental conservation. (5) From 1990 to 2022, the top 20 cited articles predominantly address diverse sub-goals of Sustainable Development Goal 7, with a common emphasis on enhancing energy efficiency, sustainability and renewable energy. These findings furnish valuable analytical insights for subsequent researchers investigating energy conservation and emission reduction as well as sustainable development endeavors.

In being aware of certain factors as the increasing of the pollution levels, the effects of the Urban Heat Island, or all the extreme climate events attributable to the constant increasing of CO2 emissions. This paper intends to propose an innovative approach to design systems and components that allow to adapt the built environment and mitigate the effects of the Climate Change in the urban Mediterranean areas. An experimental investigation at the building scale was conducted to study the environmental aspects in the early design phase that incorporate circular and ecological materials. The physical interactions between the built and the natural environment is enhanced with the upcycling design of the “Liminal Space” through the prototypological model for the “Green Responsive System”. The focus on the LS needs to push the technological definition beyond the concept of building envelope, just as the element of internal/external separation. The LS is where the “Advanced Circular Design” model can improve with the design of the GRS all the technological elements of adiabatic nature. The proposed framework enables the GRS to have a dynamic and systemic answer to the extreme change of the climatic situation in order to have a strong impact on the performance related to the environmental aspects. The parametric tools in the ACD model offers an important digital interface that can include all the regenerative requirements of the entire building considering the embodied CO2 emissions, the production and the energy consumption during the operational phase, and at the same time to control and improve the recyclability of all its components. The structure of the paper is presented as a succession of digital and physical design processes that identify all the phases for the definition of the GRS when it works on the LS. This becomes a central node in the development of the methodological framework for the upcycling design and the digital control of the responsiveness in the technological systems used for the integration of the physical aspects and the digital devices by using circular materials.

This paper presents the design and development of an integrated hybrid Solar-Darrieus wind turbine system for renewable power generation. The Darrieus wind turbine's performance is meticulously assessed using the SG6043 airfoil, determined through Q-blade simulation, and validated via comprehensive CFD simulations. The study identifies SG6043 as the optimal airfoil, surpassing alternatives. CFD simulations yield specific coefficients of power (0.2366) and moment (0.0288). The paper also introduces a hybrid prototype, showcasing of 10 W photovoltaic module and improved turbine performance with the SG6043 airfoil. The focus extends to an optimized hybrid PV solar-wind system seamlessly integrated with IoT technology for remote monitoring. Addressing weather challenges, the research suggests blade shape optimizations via Q-blade and an IoT-based solution leveraging the ESP32 Wi-Fi module. Theoretical results project electrical energy generation ranging from 0.88 kW on March 14, 2023, to 0.06 kW on February 20, 2023. Darrieus wind turbines, experiencing increased blade drag, require less lift to operate. Experimental and theoretical results converge well, affirming the model's reasonable assumptions. Beyond advancing renewable energy technologies, this research sets the stage for future investigations aimed at enhancing the efficiency and capabilities of hybrid wind-solar PV systems.

Municipal solid waste (MSW) generation is increasing in Nigeria. This poses serious environmental and public health issues because of its poor management. MSW has become a valuable resource which offers opportunities for socio-economic growth, thus the relevance of this review. The study adopted a secondary or desktop research method. The objectives of the study include identifying MSW generation rates in popular Nigerian cities, estimating daily and annual generation rates and the material and economic potential of the generated MSW. The average MSW composition for 22 cities was as follows: organics (56%), plastics (9%), paper (13%), glass and metal (3% each), textiles (2%) and others (14%). The estimated 34 million population living in the cities generates about 20378 tons of MSW each day (7.4 million tons per year). Valorization of the MSW finds applications in different—energy (power, transport, household), agriculture, construction and manufacturing. The energy potential of the generated organic, paper, plastic and textile wastes is about 947981358 kWh/ year, with a revenue potential of 1769409. This represents about 2.6% of the energy generated in Nigeria in the year 2020. The estimated revenue potential of trading the waste materials (plastic, metal, waste paper, textile and glass) for recycling ranges from 3.3 million to.4 billion. Converting wastes to raw materials will reduce the amount going to landfills/dumpsites and reduce the fiscal burden of waste management on municipalities. It will also create employment. Among others, the challenges facing MSW valorization in Nigeria include poor waste management, non-recognition of the informal waste sector, financial incapacity, etc. Thus, it is important to have adequate and effective policy and decision making.

Abstract The Sustainable Development Goals are part of the 2030 Agenda and the seventh goal is dedicated to affordable and clean energy, aiming to ensure access to affordable, reliable, sustainable and modern energy for all. Energy efficiency is an important component of this goal and is associated with reducing energy consumption and its costs and increasing the source of clean energy production. Some authors have been discussing the relation between theory and practice of sustainability, and how the practice can contribute to behaviour change. In this context, the purpose of this paper is to assess the level of knowledge of the academic community about energy efficiency practices implemented during recent years by the University of Passo Fundo, in Brazil, and students, professors and employees’ energy behaviour. The paper intends to illustrate how education practices on energy efficiency can be added to universities’ actions to improve the progress towards reducing energy consumption and promoting occupants’ change of behaviour on campus. The methodology represents a case study of the University, based on a questionnaire applied to the academic community, with a sample of 400 respondents. The results showed that the university should invest more in its energy efficiency actions but always connecting these with the academic community and highlighting their importance for the success of the practices and for a more sustainable culture on campus. Our findings show the importance of connecting energy efficiency initiatives to the academic community’s behaviour, and especially of making these initiatives more visible and engaging. The contribution of this study is expected to support other educational institutions developing similar strategies in the energy context, but could also be useful to other sectors and sustainability topics, as the need for further dissemination and awareness-raising efforts is universal.

An analysis of the sectorial structure of energy consumption shows that residential and tertiary sector buildings are the third-highest consumers, responsible for 29.5% of a city’s final energy consumption. The Building Quality Control Laboratory of the Basque Government aims to promote quality, innovation, and sustainability in buildings. To accomplish this goal, it has constructed an experimental facility with different energy generation technologies and a very versatile control system for testing different energy systems and operation modes. In this study, we tested a facility for supplying domestic hot water and heating for a multi-family house by means of a condensing boiler and an aerothermal heat pump (together with the corresponding control). This installation could reproduce the thermal demands required to be satisfied by the generation equipment through a programmed operation of the installation based on real demands. Additionally, this installation was analyzed using thermoeconomics (TE) to solve problems unable to be solved using traditional energy analyses based on the First Law of Thermodynamics. These problems include: (1) Determining the costs of the products of the installation based on physical criteria, (2) detecting the places where losses actually occur, evaluating their costs, and proposing cost-effective improvements, and (3) diagnosing issues in the installation. As a result, this paper suggests a solution to the preventive maintenance problems confronting the technical maintenance personnel for thermal installations in buildings by applying TE knowledge and using real data collected from sensors.

Over the past few decades, there has been significant attention devoted to the development of advanced technologies for achieving sustainable and environmentally friendly energy production. One prominent event in this field was the 17th SDEWES Conference (Sustainable Development of Energy, Water, and Environment Systems), which took place from November 6–10, 2022, in Paphos, Cyprus. This conference served as a gathering for 496 professionals, comprising scientists, researchers, and experts specializing in sustainable development. Participants came from 52 countries spanning six continents, with 349 attending in person and 147 joining virtually. Prof. Neven Duić, the full professor in the University of Zagreb, originated the SDEWES series since 2002, and serves as the associate editor of Energy Storage and Saving (ENSS) from the journal organization in 2021. This special issue (SI) is the second-time collaboration between SDEWES and ENSS. This editorial focuses on collating the key papers presented during the conference, with a particular emphasis on the pivotal topics including review on electrification and decarbonization, geothermal power utilization, thermal energy storage in heat pump, thermo-economic analysis on thermal system of buildings, industrial policymaking for low-emission technologies and mining investment in Latin America. ENSS also has established the SI for 18th SDEWES in 2023. Manuscripts are welcomed to 18th SDEWES held in Dubrovnik, Croatia on September 24–29, 2023.

Abstract Self-assembly is the most promising low-cost and high-throughput methodology for nanofabrication. This paper reports the optimization of a self-assembly process at room temperature for the growth of copper oxide (CuO) based nanostructures over a copper substrate using aqueous potassium hydroxide (KOH) solution as the oxidizing agent. The monoclinic phase of CuO nanostructures grown over the copper substrate was confirmed from the X-ray diffraction (XRD) and micro-Raman analysis. The overall chemical composition of nanostructures was confirmed to be that of CuO from its oxidation state using X-ray photoelectron spectroscopy (XPS). Photodetectors were engineered with the structure Cu/CuO/Ag. The photodetectors exhibited a response to both ultraviolet and visible light illumination. The optimized Cu/CuO/Ag structure exhibits a responsivity of ~ 1.65 µA/W, with an ON:OFF ratio of ~ 69 under a bias voltage of 0.01 V. The temporal dependence of photo-response for the optimized photodetector displayed the persistent nature of photoconduction indicating a delay in charge carrier recombination which could potentially be exploited for photovoltaic applications.

The penetration of new energy sources such as wind power is increasing, which consequently increases the occurrence rate of subsynchronous oscillation events. However, existing subsynchronous oscillation source-identification methods primarily analyze fixed-mode oscillations and rarely consider time-varying features, such as frequency drift, caused by the random volatility of wind farms when oscillations occur. This paper proposes a subsynchronous oscillation source-localization method that involves an enhanced short-time Fourier transform and a convolutional neural network (CNN). First, an enhanced STFT is performed to secure high-resolution time-frequency distribution (TFD) images from the measured data of the generation unit ports. Next, these TFD images are amalgamated to form a subsynchronous oscillation feature map that serves as input to the CNN to train the localization model. Ultimately, the trained CNN model realizes the online localization of subsynchronous oscillation sources. The effectiveness and accuracy of the proposed method are validated via multimachine system models simulating forced and natural oscillation events using the Power Systems Computer Aided Design platform. Test results show that the proposed method can localize subsynchronous oscillation sources online while considering unpredictable fluctuations in wind farms, thus providing a foundation for oscillation suppression in practical engineering scenarios.

Insulation failure significantly contributes to the unpredictable shutdown of power equipment. Compared to the partial discharge and high-frequency (HF) injection methods, the HF common-mode (CM) leakage current method offers a non-intrusive and highly sensitive alternative. However, the detection of HF CM currents is susceptible to interference from differential-mode (DM) currents, which exhibit high-amplitude and multifrequency components during normal operation. To address this challenge, this paper proposes a double-ring current sensor based on the principle of magnetic shielding for inverter-fed machine winding insulation monitoring. The inner ring harnesses the magnetic aggregation effect to isolate the DM current magnetic field, whereas the outer ring serves as the magnetic core of the Rogowski current sensor, enabling HF CM current monitoring. First, the magnetic field distributions of the CM and DM currents were analyzed. Then, a correlation between the sensor parameters and signal-to-noise ratio of the target HF CM current was established. Finally, an experimental study was conducted on a 3-kW PMSM for verification. The results indicate that the proposed double-ring HF CM sensor can effectively mitigate DM current interference. Compared to a single-ring sensor, a reduction of approximately 40% in the DM component was achieved, which significantly enhanced the precision of online insulation monitoring.