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The maximum output power extracted from the Photovoltaic (PV) modules is mainly dependent on ambient temperature and solar irradiance. The photovoltaic modules performance is hugely influenced by the Partial Shading (PS) effect, which results in the reduction of output power. It is caused by shadows of buildings, trees, moving clouds and towers. Under PS conditions, shaded modules receive less irradiance as compared to the unshaded modules, and this leads to overheating of PV array. The present work has been developed by a technique based on Dual Exponential Sawtooth (DES) pattern to reconfigure the PV modules so as to increase the PV output power under PS conditions along with the energy savings and economical aspects. In this technique, the PV modules of Total Cross Tied (TCT) technique and their physical locations are arranged as per DES pattern to distribute the shading effect over the entire array without altering the electrical connections of the PV modules. The DES arrangement gives the enhanced power of 41.48% by reducing the effect on any row of the shaded modules. Further, it provides the details about power sharing percentage as the number of shaded modules increase and also the affect of dynamic shade variation over the entire PV array. The proposed method validation with the existing methods for the analysis, simulation and hardware experimentation shows better performance in terms of mismatch losses and fill factor. Further, the analysis has been extended for units generated and energy savings with each module rating of 1.5 KW on 4 × 4 PV modules.

Recent studies have demonstrated that a mixture of two differently sized solid particles decreases mixture porosity while increasing thermal conductivity. This impact is limited up to temperatures of ∼400 °C at which monodisperse distributions with larger particles yield higher thermal conductivities. In this work, a numerical model of the Gen3 Particle Pilot Plant (G3P3) 20 kWt prototype heat exchanger constructed by Sandia National Laboratory (SNL) is validated for monodisperse particles distributions at its working temperatures (290–500 °C) and both particle and sCO₂ (supercritical carbon dioxide) mass flow rates (100 g/s). The validated model is then used to simulate the performance of bimodal particle distributions at working G3P3 temperatures and predicts increases in the overall heat transfer coefficient of up to 25–40% with optimal bimodal particle mixtures when compared to monodispersed particle distributions of the respective mixtures’ large particles. At these optimal particle mixtures, the average particle wall convection coefficient contributes ∼35–45% of the specific thermal resistance while the particle near-wall contact resistance contributes ∼15–25%.

In this paper available experimental data of nanorefrigerant, NRF cooling process are processed using MATLAB to determine the coefficient of performance COP as a function of Reynolds number, Re of NRF, evaporator and ambient temperatures, T_e and T_a as a novelty. The cooling process performance assessment of NRF is provided in comparison with a pure refrigerant, R through relative COP term, COP_r. The used data ranges with 20–70 nm of Al₂O₃ in R134a are at varying volume fraction, φ of 0.075–0.303% and volumetric flow rate, Q of 6.5–11 L/h for T_a in 294–306 K and T_e in 288–309 K. Re calculations are based on the thermophysical parameters evaluated at T_e not only in the cited experimental ranges of Q, φ but also extrapolated for the extended range of Q of 15–25 L/h for a generalization purpose. Since data processing is under the interactive influence of the parameters the functional relationships of COP, Re, φ, T_e are expressed as 3D graphical plots which are the start of a trial-error procedure. The experimental data are expressed in terms of fitted equations for functional relationships between various non-dimensional parameters as Re, COP, (COP*φ), (COP*T_e/T_a*φ), (Re*T_e/T_a*φ), (Re*T_e/T_a), and COP_r to provide a practical assistance for whom designing and using NRF cooling. A functional relationship of Re*(T_e/T_a) with COP_r at varying φ is found as the most critical output of the study due to the practice of the appeared parameters in cooling performance assessment. COP_r > 1 corresponds to φ > 0.151% for the processed data ranges.

The employment of limitless solar energy via semiconductor-facilitated photocatalysis represents a sustainable strategy for addressing the worldwide energy crisis and escalating environmental concerns. Thus, the advancement of effective photocatalysts represents a significant approach in addressing the energy crisis and environmental challenges. Spinel ferrites, with the general formula of MFe₂O₄ (M is a divalent metal ion such as Mg²⁺, Mn²⁺, Zn²⁺, Ni²⁺, Co²⁺, Cu²⁺, etc.), have attracted considerable research interest. Interesting physicochemical properties such as narrow bandgap, magnetic recyclability, large surface area, excellent photoactivity, non-toxicity, earth-abundance, easy synthesis, stability, and other exciting properties have seen spinel ferrites emerged as suitable candidates for photocatalytic hydrogen fuel generation. For these reasons, this review attempts to provide an overview of the application of spinel ferrites in photocatalytic hydrogen fuel generation. Herein, latest research conducted in the last decade on the use of spinel ferrite as main and co-catalyst in photocatalytic hydrogen production has been reviewed. Attention has been paid to the crystal structure, prospects and shortcomings as photocatalysts, and synthesis methods, including advantages and disadvantages of various synthesis approaches of spinel ferrites. Moreover, the pathways to improve the performance and efficiency of spinel ferrites for effective water splitting are highlighted in this review. Finally, current challenges, future outlook, suggestions and research gaps in the use of spinel ferrites in photocatalytic hydrogen evolution reaction have also been highlighted. The primary objective of this review is to demonstrate that spinel ferrites are regarded as a significant semiconductor photocatalyst due to their efficient absorption of visible light, suitable band alignment, and magnetic recyclability. This review offers a thorough understanding of spinel ferrite-based photocatalysts, encompassing recent research discoveries and progresses. It is envisioned that further investigations should focus on improving photocatalytic performance of spinel ferrites via construction of heterojunction and modifying synthesis processes.

This overview is designed to highpoint the existing field state of graphene and derived nanocomposites towards most demanding energy devices and systems. Recently, adopting efficient energy conversion and storage systems for technical practices have attained increasing research focus. Owing to unique structure, microstructure, and methodological features, graphene nanomaterials have been focused towards advanced systems like lithium ion batteries, supercapacitors, and fuel cells. Graphene nanocomposites have been recognized for high surface area, electron transference, charge capacity, specific capacitance, charge-discharge capabilities, cyclability, power conversion efficiency, fuel cell parameters, and competent features. In addition, specific features of graphene nanocomposites include exceptional microstructure and mechanical, thermal, and chemical reliability characteristics. In spite of indispensable characteristics of graphene nanocomposites, several processing and property challenges need to be resolved to achieve high-tech graphene nanocomposites towards advanced energy storage/conversion devices and systems.

The versatile applications of flexible perovskite solar cells (PSCs) have made them promising energy-harvesting devices in our daily lives. The electron transport layer (ETL)-free PSCs offer a flexible approach for harnessing energy while adding a bifacial approach that can further improve the device performance. In our study, we have optimized ETL-free bifacial PSCs via simulation by selecting the suitable front transparent electrode (FTE), hole transport layer (HTL), and rear transparent electrode (RTE). Our investigation reveals that a potential well-like structure, associated with a small conduction band offset (CBO) at the FTE/perovskite interface holds significant potential for enhancing the power conversion efficiency (PCE) of the device. The upward shift in the valance band of HTL promotes recombination and reduces the device performance. The bandgap and electron affinity of RTE highly influence the band alignment at HTL/RTE interface. The NiO/Ag/NiO (NAN) tri-layer RTE provides a better band alignment with HTL, and improves the charge transportation and, hence, the device performance. Moreover, the thickness of the interfacial defect layer at the FTE/perovskite and perovskite/HTL interfaces significantly impacts device performance. In optimizing the perovskite absorber layer, a perovskite bandgap of 1.4 eV shows maximum device performance. Our optimized device shows a remarkable PCE of >27% for both front and rear illumination.

Passive thermoelectric devices that utilize radiative cooling and solar heating have witnessed significant advancements in power generation. However, their applications and promotions are limited due to the low and unsustainable output. In this study, we propose a compact passive thermoelectric device (TED) consisting of a thermoelectric generator (TEG) equipped with a radiative cooler (RCer) and a solar absorber (SAer) for 24-h electricity generation. The RCer is made of a high-scattering porous cellulose film with a thickness of 100 μm. It is coated onto the TEG's sky-facing terminal which serves as the cold end. The SAer is made of an aluminum substrate coated with black paint. It is attached to the opposite TEG terminal which serves as the hot end. By compactly integrating the RCer and SAer, the proposed TED can harvest energy from the space for continuous electric power generation with manageable implementations. Outdoor experiments have shown that during a clear daytime, the maximum temperature difference between the TEG ends reached 7.7 °C, with an average of 2.8 °C. During the nighttime, the maximum temperature difference between TEG ends could reach 1.7 °C, with an average of 0.9 °C. The maximum power outputs during daytime and nighttime are 351.6 mW·m⁻² and 31.0 mW·m⁻², respectively. This study introduces a conceptual design for a compact passive TED and lays the foundation for practical applications in powering outdoor microdevices.

Electrochemical ammonia synthesis is being widely investigated to couple with renewable electricity for future sustainable ammonia production. Protonic ceramic electrochemical cells (PCECs) possess superior energy transfer efficiency and remarkable flexibility to produce high-demand chemicals such as H₂, CH₄, and NH₃ from readily available feedstocks (e.g., H₂O, CO₂, N₂). Despite recent advances that have been established, the research for the high-efficiency PCECs for practical ammonia synthesis continues. In this review, we summarized the recent progress of PCECs for ammonia synthesis. First, we briefly introduce the basic mechanisms and protocols of the ammonia synthesis. Then, we systemically introduce the cell configurations, representative electrolytes and electrodes of PCECs for the ammonia synthesis. We highlight the strategies to tune the ion/electron mobility and the catalytic performance, which are related to the defect structures and redox properties of the electrolyte/electrode, and the opportunities for next-generation ammonia synthesis. Finally, perspectives on ammonia synthesis in PCECs are proposed consering the current challenges.

The study highlights effect of surface modification of SnO₂ photoelectrode by MgO coating on photovoltaic properties of dye-sensitized solar cells (DSSCs). A thin coating of MgO on SnO₂ photoelectrode was prepared using sol-gel-derived dip coating technique. The bare SnO₂ and MgO coated SnO₂ composite photoanodes was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS) and UV–vis spectrophotometer. The optical absorption study revealed that the modification in SnO₂ by MgO coating caused an increase in absorption by photoanode in visible region. The solar cell was demonstrated by preparing FTO|SnO₂|Dye|MgO|Electrolyte|Pt coated FTO device structure and tested with current density-voltage (J-V) measurement. The effect of precursor concentration of MgO coating on the performance of DSSCs were investigated. It was found that, optimized coating of MgO for 90 seconds on SnO₂ improved all photovoltaic parameters, resulting in enhancement in efficiency by 42% compared to that of DSSC with bare SnO₂ photoanode. The coating of MgO would have reduced the trap states and suppressed interfacial recombination losses by preventing back electron transfer from the conduction band of the semiconductor to HOMO of dye molecule or redox species.