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Background: In recent years, the integration of renewable energy sources into the grid has increased exponentially. However, one significant challenge in integrating these renewable sources into the grid is intermittency. Objective: To address this challenge, accurate PV power forecasting techniques are crucial for operations and maintenance and day-to-day operations monitoring in solar plants. Methods: In the present work, a hybrid approach that combines Deep Learning (DL) and Numerical Weather Prediction (NWP) with electrical models for PV power forecasting is proposed Results: The outcomes of the study involve evaluating the performance of the proposed model in comparison to a Physical model and a DL model for predicting solar PV power one day ahead and two days ahead. The results indicate that the prediction accuracy of PV power decreases and the error rates increase when forecasting two days ahead, as compared to one day ahead. Conclusion: The obtained results demonstrate that DL models combined with NWP and electrical models can improve PV Power forecasting compared to a Physical model and a DL model.

Abstract This paper investigates the forced convection of alumina-water nanofluids within helical tubes, maintaining a constant wall temperature and assuming thermal equilibrium between the nanoparticles and the base fluid. The nanofluid model incorporates the effects of alumina (Al2O3) nanoparticle volume fraction, diameter, and temperature on thermophysical properties. The governing equations are solved using the Forward-Time Central-Space Finite Volume method in conjunction with the simple algorithm. Numerical results are validated against experimental data, demonstrating high accuracy. The study explores the effects of pitch size, curvature ratio, nanoparticle volume fraction, nanoparticle diameter, and Reynolds number on velocity contours, temperature profiles, secondary flow, thermophysical properties, friction coefficient, and heat transfer rate. Additionally, the figure of merit evaluates the impact of these parameters on the thermal performance of the system. The results indicate that an increase in Reynolds number and nanoparticle diameter negatively affects thermal performance, while higher nanoparticle volume fraction, curvature ratio, and pitch size enhance it. Furthermore, incorporating nanoparticles in straight tubes proves to be more advantageous compared to helical tubes. This study tested volumetric ratios of 1%, 2%, and 4%, which resulted in increases in heat transfer coefficients of 21%, 32%, and 43%, respectively, compared to pure water under similar conditions, such as Reynolds number and coil pitch.

Energy poverty is a complex, multifaceted problem which negatively affects many households around the world. Therefore, its mitigation is one of the most relevant policy goals for governments nowdays. The events of COVID-19, and the surge in energy prices due to the postpandemic recovery, the war in Ukraine and the energy crisis worsened an already difficult situation for many citizens, increasing energy poverty. However, these detrimental effects on energy poverty are unlikely to have been homogenous across different household types, impacting some more than others. Although energy poverty in general and the determinants of energy poverty in particular are topics which have received attention from academics in the past, the analysis of the impact of those events on specific types of households has not. The aim of this paper is to assess the impact of COVID, the post-pandemic recovery and the war in Ukraine on energy poverty through an analysis of their effects on different types of households and dwellings. Using a database of Spanish households in 2019 and 2022, and binary probit estimations, the results show that those household heads who are foreign nationals, females, older than 67 years, without education and with lower income levels and households with dependent children, whose members do not have a job and live in a detached dwelling, in a rented house, in a dwelling located in a cold region, in a rural area and in an old dwelling are more likely to be energy poor. Both events had a negative effect on energy poverty in very specific types of households: those in which the household head is a male, households whose members do not have a job, are older than 67 years, have children, are less educated, have lower income levels and live in detached dwellings. Analysing the most affected household types and most influential determinants of energy poverty is key to propose effective and efficient policy interventions which mitigate it. These findings call for the adoption of effective targeted policy interventions which focus on the factors that are more likely to reduce EP. They suggest that additional policy efforts to mitigate energy poverty should be put on specific households.

The increasing commercial interest in silicon-based anode materials for Li-ion batteries has driven the development of advanced structural designs to address the challenges of poor cycling stability. This study examines the structure of commercial silicon/carbon composite materials where nano silicon clusters are embedded within a carbon matrix. The size of silicon and carbon nanoclusters is determined by comparing experimental X-ray diffraction patterns with calculated patterns based on the Debye scattering formalism, as implemented in the program DEBUSSY. The size, morphology, surface areas, and porosities of the carbon matrix and composite are measured, along with their resulting tap and true densities. Their electrochemical performance is also assessed to determine operando stack growth and cycling stability. By restricting silicon cluster sizes to sub-nanometer dimensions within a porous carbon matrix, a low specific surface area can be achieved along with a specific capacity of ∼2000 mAh g−1. Additionally, this approach results in high tap density values close to 1 g cc−1, reduces reversible stack growth, and minimizes irreversible stack growth caused by particle cracking during volume changes, thereby significantly enhancing the overall stability and performance of the anode material.

Hydrogen is an energy carrier that can support the development of sustainable and flexible energy systems. However, decarbonization can occur when green sources are used for energy production and appropriate water use is manifested. This work aims to propose a socio-economic analysis of hydrogen production from an integrated wind and electrolysis plant in southern Italy. The estimated production amounts to about 1.8 million kg and the LCOH is calculated to be 3.60 €/kg in the base scenario. Analyses of the alternative scenarios allow us to observe that with a high probability the value ranges between 3.20–4.00 €/kg and that the capacity factor is the factor that most affects the economic results. Social analysis, conducted through an online survey, shows a strong knowledge gap as only 27.5 % claim to know the difference between green and grey hydrogen. There is a slight propensity to install systems near their homes, but this tends to increase due to increased knowledge on the topic. Respondents state sustainable behaviours, and this study suggests that these aspects should also be transformed into the energy choices that are implemented every day. The study suggests information to policy-makers, businesses and citizens as it outlines that green hydrogen is an operations strategy that moves toward sustainable development.

Convex relaxations of the optimal power flow (OPF) problem provide an efficient alternative to solving the intractable alternating current (AC) optimal power flow. The conic subset of OPF convex relaxations, in particular, greatly accelerate resolution while leading to high-quality approximations that are exact in several scenarios. However, the sufficient conditions guaranteeing exactness are stringent, e.g., requiring radial topologies. In this short communication, we present two equivalent ex post conditions for the exactness of any conic relaxation of the OPF. These rely on obtaining either a rank-1 voltage matrix or self-coherent cycles. Instead of relying on sufficient conditions a priori, satisfying one of the presented ex post conditions acts as an exactness certificate for the computed solution. The operator can therefore obtain an optimality guarantee when solving a conic relaxation even when a priori exactness requirements are not met. Finally, we present numerical examples from the MATPOWER library where the ex post conditions hold even though the exactness sufficient conditions do not, thereby illustrating the use of the conditions.

This paper investigates the use of a passive in-flight battery thermal management system for an electric trainer aircraft. The proposed architecture employs a high-conductivity heat pipe coupled with a heat sink to provide cooling. Two different thermal management approaches are used for ground and flight operations. During charge, a ground-based air conditioning unit is used for thermal management. In flight, the system relies on preconditioning of the battery pack’s thermal mass to limit the temperature rise to acceptable levels, reducing the onboard weight and complexity associated with the battery thermal management system. To assess the performance of the proposed system over the entire lifetime of the battery pack, for both flight and ground operations, a coupled electrothermal-aging model based on semi-empirical data was created and validated experimentally for a notional touch-and-go training mission of a conceptual electric Cessna 172N. Resulting time-dependent performance diagrams presenting the evolution of maximum battery temperature, the ground turnaround time, and the capacity fade are used to determine operational constraints throughout the 2-year-and-a-half lifetime of the pack.

Grid-forming (GFM) control has been considered a promising solution for accommodating large-scale power electronics converters into modern power grids thanks to its grid-friendly dynamics, in particular, voltage source behavior on the AC side. The voltage source behavior of GFM converters can provide voltage support for the power grid, and therefore enhance the power grid (voltage) strength. However, grid-following (GFL) converters can also perform constant AC voltage magnitude control by properly regulating their reactive current, which may also behave like a voltage source. Currently, it still remains unclear what are the essential differences between the voltage source behaviors of GFL and GFM converters, and which type of voltage source behavior can enhance the power grid strength. In this paper, we will demonstrate that only GFM converters can provide effective voltage source behavior and enhance the power grid strength in terms of small signal dynamics. Based on our analysis, we further study the problem of how to configure GFM converters in the grid and how many GFM converters we will need. We investigate how the capacity ratio between GFM and GFL converters affects the equivalent power grid strength and thus the small signal stability of the system. We give guidelines on how to choose this ratio to achieve a desired stability margin. We validate our analysis using high-fidelity simulations.

Aim:: This article describes the use of graphite(Gr) and boron carbide (B4C) as multiple nanoparticle reinforcements in LM25 aluminum alloy. Because boron carbide naturally absorbs neutron radiation, aluminium alloy reinforced with boron carbide metal matrix composite has gained interest in nuclear shielding applications. The primary goal of the endeavor is to create composite materials with high wear resistance, high microhardness, and high ultimate tensile strength for use in nuclear applications. Patents on Gr and B4C can cover a wide range of subjects, including the synthesis and production methods of structural, armor materials, abrasives, and nuclear shielding. Background:: Science and Technology have brought a vast change to human life. The human burden has been minimized by the use of innovation in developing new and innovative technologies. To improve the quality of human life, fresh, lightweight, and creative materials are being used, which play a vital role in science and technology and reduce the human workload. Composite materials made of metal are being used because they are lightweight. Neutron absorption, high ultimate strength, high wear resistance, high microhardness, high thermal and electrical conductivity, high vacuum environmental resistance, and low coefficient of thermal expansion under static and dynamic conditions are all demands for the hybrid metal matrix composites utilized in nuclear applications. Objective:: Stir casting is used to create the novel LM 25 aluminum alloy/graphite and boron carbide hybrid nanocomposites. • The mechanical properties such as ultimate tensile strength, yield strength, percentage of elongation, microhardness, and wear behavior are calculated. • Three analyses are performed: microstructure, worn surface analysis, and fracture analysis of the tensile specimen. Method:: • Stir casting process • Tensile, Hardness, Wear Test • Materials Characterization – FESEM, Optical Microscopy, EDS Results:: The mechanical properties values are 308.76 MPa, 293.51 MPa, 7.8, 169.2 VHN, and 0.01854mm3/m intended for ultimate tensile strength, yield strength, percentage of elongation, microhardness, and wear behavior, respectively. This implies that the synthesized composite may be used in nuclear applications successfully Conclusion:: The subsequent explanation was drawn from this investigative work: • The LM 25/B4C/Gr hybrid nanocomposite was successfully manufactured by employing the stir casting technique. For nuclear shielding applications, these composites were prepared with three different weight percentages of nanoparticle reinforcements in 2,4,6% Boron carbide and constant 4 wt.% graphite. • The microhardness values of the three-hybrid nanocomposite fabricated castings were determined to be 143.4VHN, 156.7VHN, and 169.2VHN, respectively. • The hybrid nano composite's microstructure revealed that the underlying LM 25 aluminum alloy matrix's finegrained, evenly dispersed nanoparticles of graphite and boron carbide were present. • The microtensile test was carried out and it was found that the ultimate tensile strength, yield strength and percentage of elongation values are 281.35MPa, 296.52MPa, 308.76MPa, 269.43, 274.69, 293.51 and 3.4, 5.7, 7.8 respectively. • Deformation caused the hybrid LM 25/B4C/Gr nanocomposite to fracture in ductile mode. Dimples and cavities are seen in the fracture because of the nanoparticle reinforcements and the matrix's tight connection. • The wear loss of nanocomposite based on the input parameter applied load, sliding velocity and sliding distance values are 0.02456, 0.02189, 0.01854, 0.02892, 0.02586, 0.02315 and 0.02682, 0.02254, 0.02015 mm3/m, respectively. • The LM 25 alloy's elemental analysis displays the aluminum alloy phase as the largest peak and the remaining elements as smaller peaks; also, the spectral analysis reveals the presence of boron (B), graphite (C), silicon, and ferrous in the aluminum alloy LM 25. • Through worn surface FESEM investigation, it was shown that under sliding and high load situations, debris, delamination, and groove develop. Further rupture, fine, and continuous grooves were seen when low stress and sliding circumstances were applied to the LM 25/B4C/Gr and stir cast specimen. This result implies the presence of mild adhesive and delamination wear processes.

This paper aims to unveil the intellectual structure and knowledge flow within Türkiye's academic landscape, shedding light on influential research clusters and highlighting the interconnections between different research themes. The manuscript also synthesizes findings from a Web of Science database, elucidating the growth trajectories of Türkiye's contributions to the global discourse on energy, fuels, and hydrogen. Additionally, the role of interdisciplinary collaboration has been explored and the impact of Türkiye's research output on the international stage has been assessed. According to results, the oldest date goes back to 1972 for energy&fuels topic and 1989 for hydrogen topic. Whereas Ayhan Demirbas and Ibrahim Dincer are the most productive authors, Istanbul Technical University and Yildiz Technical University are the most productive institutions. Moreover, USA and Canada are the most efficient countries for colloborations. Last of all, while new trends in Energy&Fuels publications have been observed as machine learning, supercapacitor, nanoparticles, electric vehicle and graphene, new trends in hydrogen publications were observed as methanolysis, multigeneration, ammonia, thermodynamic analysis and graphene.