Renewable Energy Applications Research Articles

High-precision prediction of microalgae biofuel production efficiency: employing ELG ensemble method

Microalgae biofuels are considered a significant source of future renewable energy due to their efficient photosynthesis and rapid growth rates. However, practical applications face numerous challenges such as variations in environmental conditions, high cultivation costs, and energy losses during production. In this study, we propose an ensemble model called ELG, integrating Empirical Mode Decomposition (EMD), Long Short-Term Memory (LSTM), and Gradient Boosting Machine (GBM), to enhance prediction accuracy. The model is tested on two primary datasets: the EIA (U.S. Energy Information Administration) dataset and the NREL (National Renewable Energy Laboratory) dataset, both of which provide extensive data on biofuel production and environmental conditions. Experimental results demonstrate the superior performance of the ELG model, achieving an RMSE of 0.089 and MAPE of 2.02% on the EIA dataset, and an RMSE of 0.1 and MAPE of 2.21% on the NREL dataset. These metrics indicate that the ELG model outperforms existing models in predicting the efficiency of microalgae biofuel production. The integration of EMD for preprocessing, LSTM for capturing temporal dependencies, and GBM for optimizing prediction outputs significantly improves the model’s predictive accuracy and robustness. This research, through high-precision prediction of microalgae biofuel production efficiency, optimizes resource allocation and enhances economic feasibility. It advances technological capabilities and scientific understanding in the field of microalgae biofuels and provides a robust framework for other renewable energy applications.

Synergistic Passivation Strategies for Enhancing Efficiency and Stability of Perovskite Solar Cells

Perovskite solar cells (PSCs) are celebrated for their potential in clean and renewable energy applications. However, their performance and longevity are often compromised by surface and grain boundary defects. Herein, a posttreatment strategy using 4‐hydroxy‐4′‐biphenylcarboxylic acid ethyl ester (EHBC) is introduced to passivate these defects in perovskite films, thereby enhancing the performance of PSCs. As a Lewis base, the carbonyl group of EHBC interacts with uncoordinated lead ions to passivate lead vacancy defects, while the hydroxyl group forms hydrogen bonds with iodide ions, reducing their migration. Additionally, the hydrophobic biphenyl groups of EHBC enhance the resistance to moisture. The study demonstrates that PSCs treated with EHBC retain 69% of their initial performance after 700 h under 30% relative humidity, achieving a maximum power conversion efficiency (PCE) of 24.48%, a significant improvement over the untreated control PSCs (PCE = 23.04%). This synergistic passivation strategy offers an effective approach for fabricating high‐efficiency and stable PSCs.

Optimizing Charge Separation and Transport: Enhanced Photoelectrochemical Water Splitting in α-Fe2O3/CZTS Nanorod Arrays

This study explores the enhancement of α-Fe2O3 (hematite) nanorod arrays for photoelec-trochemical applications by constructing a Cu2ZnSnS4 (CZTS) heterojunction. While α-Fe2O3 offers good stability, a low cost, and environmental benefits, its efficiency is limited by slow oxygen evolution kinetics, high carrier recombination rates, and low conductivity. By introducing CZTS, a material with strong light absorption and charge transport properties, we enhance the separation of photogenerated charge carriers, reduce charge transfer resistance, and increase the carrier concentration, thereby boosting the overall photoelectrochemical performance. The experimental results show that a modified FC-15 photoanode achieves a photocurrent density of 3.40 mA/cm2 at 1.60 V vs. RHE, a substantial increase compared to 0.40 mA/cm2 for unmodified α-Fe2O3. Band gap analysis reveals a reduced band gap in the FC-15 material, enhancing light absorption and boosting the photoelectrocatalytic performance. In photoelectrochemical water-splitting tests, the FC-15 photoanode achieves a hydrogen production rate of 41.6 μmol/cm2/h, which is significantly improved over the unmodified sample at 5.64 μmol/cm2/h. These findings indicate that the CZTS/α-Fe2O3 heterojunction effectively promotes charge separation, enhances charge transport, and improves light absorption, substantially increasing photocatalytic efficiency. This heterojunction approach offers new insights and technical strategies for developing photocatalytic materials with potential applications in renewable energy.

Revesting the spatial spillover effects of renewable energy in curbing carbon emissions: Evidence from China

Renewable energy is fundamental to achieving China's peak carbon and carbon neutrality targets. Despite the extremely rapid growth in the share of renewable energy generation in terms of provincial-level regions, the impact of renewable energy generation on carbon emission reduction and whether this association is spatially correlated have not been fully recognized. To address this issue, this paper explores the spatial impact effect of renewable energy applications on carbon emissions using Chinese provincial panel data from 1990 to 2020 and a multi-panel spatial econometric model. The results show that the contribution of emission reduction mainly comes from the provincial clean energy mix, while the exclusion of out-of-province power plants also helps to curb their carbon emissions. In addition, in the context of large-scale penetration of renewable energy, grid infrastructure for cross-provincial power trading will contribute to cross-provincial emission reduction. Regulators should take measures to promote coordination of emission reduction policies among provinces in a unified national carbon market, rather than simplifying the allocation of responsibilities in provincial markets. Based on the findings of this paper, there is a need to rationalize and optimize the geospatial distribution of renewable energy projects in the future, so as to maximize the potential of renewable energy to contribute to carbon emission reduction.

High-gain DC-DC converter with triple-winding coupled inductor for enhanced power quality in renewable energy applications

High-gain DC-DC converter with triple-winding coupled inductor for enhanced power quality in renewable energy applications

Numerical investigation for bioconvection flow of radiative viscoelastic nanofluid with triple diffusion and higher-order slip effects in a porous medium

Owing to enhanced thermal features, the study of nanofluids has become motivating research area which include various applications in renewable energy, thermal management devices, heat exchangers, microelectronics cooling, automotive industry etc. Owing such applications in mind, the aim of current investigation is to present a triple diffusion flow of viscoelastic nanofluid in presence of higher order slip effects. The problem investigates the insight of thermo-diffusion phenomenon with visualization of heat transfer, solutal concentration, nanoparticles concentration and bioconvection applications. The radiative impact with nonlinear relations and heat source are incorporated in the heat equation. The numerical simulations of problem have been performed via shooting scheme. Various applications are claimed with variation of flow parameters. It has been observed that the increase of the slip parameter enhances both the temperature nanofluid and concentration profiles. The solutal concentration profile increases due to Dufour Lewis number. Moreover, the change in nano-Lewis number leads to a decrease of concentration profile.

A Comprehensive Review of Remaining Useful Life Estimation Approaches for Rotating Machinery

This review paper comprehensively analyzes the prognosis of rotating machines (RMs), focusing on mechanical-flaw and remaining-useful-life (RUL) estimation in industrial and renewable energy applications. It introduces common mechanical faults in rotating machinery, their causes, and their potential impacts on RM performance and longevity, particularly in wind, wave, and tidal energy systems, where reliability is crucial. The study outlines the primary procedures for RUL estimation, including data acquisition, health indicator (HI) construction, failure threshold (FT) determination, RUL estimation approaches, and evaluation metrics, through a detailed review of published work from the past six years. A detailed investigation of HI design using mechanical-signal-based, model-based, and artificial intelligence (AI)-based techniques is presented, emphasizing their relevance to condition monitoring and fault detection in offshore and hybrid renewable energy systems. The paper thoroughly explores the use of physics-based, data-driven, and hybrid models for prognosis. Additionally, the review delves into the application of advanced methods such as transfer learning and physics-informed neural networks for RUL estimation. The advantages and disadvantages of each method are discussed in detail, providing a foundation for optimizing condition-monitoring strategies. Finally, the paper identifies open challenges in prognostics of RMs and concludes with critical suggestions for future research to enhance the reliability of these technologies.

Thermal kinetic analysis and characterization of water hyacinth biomass for renewable energy application

Thermal kinetic analysis and characterization of water hyacinth biomass for renewable energy application

Surface iron concentration gradient: A strategy to suppress Mn3+ Jahn-Teller effect in lithium manganese iron phosphate

To address the low energy density of LiFePO4 (LFP) for electric vehicles and high-voltage energy storage, LiMn0.5Fe0.5PO4 (LMFP) provides a potential solution but faces performance degradation due to Mn3+-induced Jahn-Teller distortion and Mn ion dissolution during cycling. This study proposes a surface engineering strategy to enhance LMFP’s electrochemical performance by increasing surface iron concentration and reducing manganese content, based on the electronic differences between Mn3+ and Fe3+ in MO6 octahedra. Density Functional Theory (DFT) calculations confirmed the viability of this approach by analyzing volume changes and binding energies with HF during charging. Guided by DFT, an LMFP@LFP/C material was synthesized with a high-iron-concentration surface layer (∼2 nm), as observed through AC-STEM. Post-cycling TEM analysis and corrosion simulations demonstrated that LMFP@LFP/C suppresses Mn ion dissolution and stabilizes the crystal lattice compared to unmodified LMFP/C. Electrochemical tests showed that LMFP@LFP/C has superior electronic conductivity and faster lithium-ion diffusion. It delivered an initial discharge capacity of 150.82 mAh g−1 at 0.1C, surpassing LMFP/C (147.65 mAh g−1). At 1C, LMFP@LFP/C retained 95.85 % of its capacity after 500 cycles, significantly outperforming LMFP/C (74.18 %). This surface modification strategy advances phosphate-based cathode materials for electric vehicles and renewable energy applications.

Nanophysics Is Boosting Nanotechnology for Clean Renewable Energy.

As nanophysics constitutes the scientific core of nanotechnology, it has a decisive potential for advancing clean renewable energy applications. Starting with a brief foray into the realms of nanophysics' potential, this review manuscript is expected to contribute to understanding why and how this science's eruption is leading to nanotechnological innovations impacting the clean renewable energy economy. Many environmentally friendly energy sources are considered clean since they produce minimal pollution and greenhouse gas emissions; however, not all are renewable. This manuscript focuses on experimental achievements where nanophysics helps reduce the operating costs of clean renewable energy by improving efficiency indicators, thereby ensuring energy sustainability. Improving material properties at the nanoscale, increasing the active surface areas of reactants, achieving precise control of the physical properties of nano-objects, and using advanced nanoscale characterization techniques are the subject of this in-depth analysis. This will allow the reader to understand how nanomaterials can be engineered with specific applications in clean energy technologies. A special emphasis is placed on the role of such signs of progress in hydrogen production and clean storage methods, as green hydrogen technologies are unavoidable in the current panorama of energy sustainability.

The influence of bandgap tunability on the physical features of Rb2LiSbX6 (X=Cl, Br) double perovskites in the context of green technologies

Rubidium-based perovskites have the potential to significantly transform renewable energies by making devices more affordable and environmentally friendly. The DFT is employed to conduct an inclusive analysis of the elastic, structural, electronic structure, transport and optoelectronic properties of Rb2LiSbCl6 and Rb2LiSbBr6. The analysis of tolerance factor, optimization curves and octahedral tilting serves to validate the structural stability. The brittle character of Rb2LiSbCl6 and ductile nature of Rb2LiSbBr6 are substantiated by their mechanical properties. The (W-L) symmetry points for Rb2LiSbCl6 and Rb2LiSbBr6 demonstrate the indirect bandgap of 3.72 eV and 2.9 eV, respectively. A decline in the bandgap is observed upon substitution of the Cl with Br atom. The Kramer-Kronig relations are employed for the assessment of the optical properties, revealing substantial absorption within the UV spectrum for both structures, hence enabling their application in optoelectronics. A wide range of thermoelectric properties are computed utilizing the Boltzmann semi-classical theory. Perovskites possess considerable promise for the implementation of renewable energy applications due to their notable ZT values (i.e., 0.73 for Rb2LiSbCl6 and 0.74 for Rb2LiSbBr6), as well as their enhanced Seebeck coefficients. These characteristics enhance their appropriateness for usage in green technologies.

A comprehensive review of effective parameters to improve the performance of the Savonius turbine using a computational model and comparison with practical results

Amidst growing global concerns over climate change and escalating greenhouse gas emissions from fossil fuels, the pursuit of renewable energy sources has become critical. This study focuses on harnessing hydropower using Savonius turbines, which are known for their efficiency in generating energy at lower flow rates. However, the intrinsic low efficiency of these turbines necessitates precise optimization tailored to specific river or channel conditions. In this research, we optimized the performance of Savonius turbines by analyzing key parameters such as the height-to-diameter ratio, blade twist, and the integration of multi-stage configurations with deflectors. Our findings reveal significant efficiency improvements through strategic modifications. Specifically, by reducing the height-to-diameter ratio from 1.2 to 0.8 and maintaining a Tip Speed Ratio (TSR) of 0.6, the power coefficient increased by 15%, from 0.33 to 0.38. Further optimization was achieved by adjusting the blade twist angle, with an increase in power coefficient up to an optimal angle of 45°, beyond which efficiency declined. Implementing a two-stage turbine setup with a 90-degree phase difference between stages further improved the power coefficient to 0.51 at the same TSR. Additionally, the use of deflectors, particularly at a 90° angle, significantly boosted the power coefficient, highlighting their effectiveness in optimizing water flow impact on the turbine. This comprehensive study not only advances the understanding of Savonius turbine optimization but also contributes to broader renewable energy applications. The research offers critical insights into sustainable hydroelectric power generation, providing practical solutions to enhance turbine performance for real-world applications.

PENERAPAN ENERGI TERBARUKAN DI KAWASAN WISATA LUMBUNG MATARAMAN DESA BENDUNG GUNUNGKIDUL

The community service activities carried out focus on the application of renewable energy in the Lumbung Mataraman tourism area, Bendung Village, Semin, Gunungkidul. The community service activities carried out are strategic steps in supporting a sustainable green economy. By utilising appropriate technology (TTG) in the form of solar panels and wind turbines, this area is expected to reduce dependence on fossil energy and increase operational energy efficiency. In addition, the tourism area has the potential to become an educational model on the use of renewable energy, both for local communities and tourists. The methods used in this research include qualitative and quantitative approaches. The qualitative approach was conducted through interviews with local stakeholders, such as tourism area managers, communities, and renewable energy experts. In addition, field observations were conducted to understand energy needs and the potential for implementing renewable energy technologies. The quantitative approach involved analysing current energy consumption data and calculating the potential of renewable energy that can be applied, such as solar panels and wind turbines. The results of the activities show that the implementation of renewable energy in Lumbung Mataraman can reduce dependence on fossil energy sources, lower carbon emissions, and provide additional economic benefits through energy cost savings and educational media in the use of renewable energy.

Evaluation of Thermal and Mechanical Properties of Bi-In-Sn/WO3 Composites for Efficient Heat Dissipation.

Phase change materials (PCMs) offer promising solutions for efficient thermal management in electronic devices, energy storage systems, and renewable energy applications due to their capacity to store and release significant thermal energy during phase transitions. This study investigates the thermal and physical properties of Bi-In-Sn/WO3 composites, specifically for their use as phase change thermal interface materials (PCM-TIMs). The Bi-In-Sn/WO3 composite was synthesized through mechanochemical grinding, which enabled the uniform dispersion of WO3 particles within the Bi-In-Sn alloy matrix. The addition of WO3 particles markedly improved the composite's thermal conductivity and transformed its physical form into a putty-like consistency, addressing leakage issues typically associated with pure Bi-In-Sn alloys. Microstructural analyses demonstrated the existence of a continuous interface between the liquid metal and WO3 phases, with no gaps, ensuring structural stability. Thermal performance tests demonstrated that the Bi-In-Sn/WO3 composite achieved improved thermal conductivity, and reduced volumetric latent heat, and there was a slight increase in thermal contact resistance with higher WO3 content. These findings highlight the potential of Bi-In-Sn/WO3 composites for utilization as advanced PCM-TIMs, offering enhanced heat dissipation, stability, and physical integrity for high-performance electronic and energy systems.

Investigation of Electronic, Mechanical, Optical, and Thermoelectric Characteristics of Halide Double Perovskites Na2AuInZ6 (Z = Cl, Br, and I) for Solar Cells and Renewable Energy Applications

Investigation of Electronic, Mechanical, Optical, and Thermoelectric Characteristics of Halide Double Perovskites Na2AuInZ6 (Z = Cl, Br, and I) for Solar Cells and Renewable Energy Applications

Enhancing optical properties of Ba-Ni ferrite through nonmagnetic ion doping for sustainable green technologies and renewable energy applications

Barium ferrite powder was produced using a standard ceramic procedure, and its structure and optical properties were investigated. X-ray diffraction analysis (XRD) showed that the powder had a w-type hexagonal structure. The crystallite size was at approximately 35–36 nm, with bulk density and lattice constants increasing as zinc concentration rose. Conversely, X-ray density and porosity decreased with the increasing zinc concentration. This material has useful optical properties, as well as the standard ferrimagnetic properties of barium ferrite, which make it suitable for use in recording media. Ferrimagnetic behavior, which is useful for recording media, occurs because the powder's crystallites have their unit cell axes aligned. Up to the near-infrared part of the spectrum, the powder was found to have a very low absorption coefficient. Both of these properties—an arrangement that gives rise to ferrimagnetism and a corresponding low optical density—make barium ferrite very attractive for high-density recording and microwave applications. Fourier transform infrared spectra of the samples were recorded in the wavenumber range of 400–4000 cm−1 and supported the X-ray diffraction findings by confirming the idea of the formation of W-type hexagonal ferrite by the presence of two prominent peaks at 454 and 591 cm−1 in the FTIR spectra. Zinc addition was also found to enhance the optical properties of the material. The UV–VIS analysis confirms that the band gap energy of Ba-Ni ferrite was indeed reduced by zinc doping. Values decrease from 3.34 eV to 3.20 eV for direct transitions and from 2.96 eV to 2.79 eV for indirect transitions, using Tauc equation. That means that zinc doping enhances the optical properties of Ba ferrite without affecting the hexagonal structure of Ba-Ni ferrite. Moreover, key parameters of optical performance such as the dielectric constant, the extinction coefficient, the penetration depth, and the refractive index show a dramatic increase with a rise in zinc concentration. These attributes make zinc-doped Ba-Ni ferrite a promising optoelectronic material. The material also showed high absorbance in the wavelengths ranging from 334 to 338 nm, which makes it good for the solar cell applications. Overall, zinc-doped Ba-Ni ferrite is a good candidate for sustainable and renewable energy applications. Our study of the optical properties of barium ferrite up to the near-infrared part of the spectrum demonstrated that the powdered material has a very low absorption coefficient. Indeed, the combination of ferrimagnetism and low optical density makes barium ferrite particularly appealing for use in high-density recording and microwave technology applications.

Investigation of the catalytic activity of trimetallic CuAgAu aerogels for the electrochemical reduction of CO<sub>2</sub> to CO

Given the growing demand for efficient catalysts in sustainable energy applications, this study investigates the structural characterization and catalytic activity of CuAgAu trimetallic aerogels synthesized via a sol-gel method. Transmission electron microscopy (TEM) revealed a porous network structure with uniformly dispersed trimetallic nanoparticles averaging 5-10 nm in size, which indicates a successful synthesis and nanostructure formation. X-ray diffraction analysis confirmed the formation of a face-centered cubic structure, with distinct diffraction peaks observed at positions corresponding to the (111), (200), and (220) planes of Cu, Ag, and Au, respectively. These structural features are critical for understanding the crystalline nature and stability of the aerogels. The catalytic activity of CuAgAu aerogels for CO2 reduction was evaluated using linear sweep voltammetry, which showed notable enhancements in current densities at various applied potentials relative to the reversible hydrogen electrode. These findings indicate the aerogels’ effectiveness as catalysts for CO2 conversion. Furthermore, Faradaic efficiency measurements revealed a high selectivity in the conversion of CO2 to CO, achieving a high Faradaic efficiency of 85%, which suggests that the aerogels’ capability to efficiently utilize electrons in producing CO, as a valuable precursor in renewable energy and chemical synthesis applications. The combination of structural integrity, catalytic performance, and high selectivity positions CuAgAu aerogels as promising approach for sustainable energy technologies.

Unveiling half-metallic, thermoelectric and optoelectronic behavior of the new Heusler alloy RbCrZ (Z = Si, Ge): a DFT perspective

Abstract Utilizing the density functional theory (DFT) method, this study aims to predict with precision the structural, elastic, electronic, magnetic, thermoelectric, thermal, and optical properties of two recently discovered half-Heusler alloys, namely RbCrSi and RbCrGe. The exchange and correlation potential are accounted for using the generalized gradient approximation of Perdew–Burke–Ernzerhof (GGA-PBE) and the Tran–Blaha-modified Becke–Johnson exchange potential (TB-mBJ). Through structural analysis, it is observed that both RbCrSi and RbCrGe alloys exhibit energetic stability in a type-3 structure with a ferromagnetic (FM) state. Both alloys exhibit half-metallic properties and integer magnetic moments of 3 μB, following the Slater-Pauli rule. Additionally, elastic calculations confirm their mechanical stability and anisotropic ductile behavior. The quasi-harmonic Debye model (QHDM) is employed for calculating thermodynamic properties, while the BoltzTraP code, based on semi-classical Boltzmann theory (SCBT), is utilized for evaluating thermoelectric properties. Findings reveal that RbCrZ alloys (with Z = Si, Ge) exhibit high figure of merit (ZT) values nearing unity at highest temperature. Consequently, the newfound half-Heusler alloys RbCrSi and RbCrGe hold significant promise for applications in thermoelectricity and spintronic devices. This comprehensive analysis underscores the potential of these alloys in the realm of renewable energy applications.

PV Based Single Stage Cascaded Seven Level Modular Multilevel Converter with ZSV Control for Grid Interfaced System

Objectives: Climatic perturbation and environmental factors affect solar power generation. When these solar panels are connected to the grid it causes power quality issues such as voltage harmonics, voltage distortion, etc. These problems are addressed in this paper using a distributed MPPT algorithm. Methods: Multilevel inverters have made remarkable contributions to renewable energy, high voltage, and other high-power applications. Hence, a single-stage Cascaded Seven-Level Modular Multilevel Converter (CSLMMC) is used to address the issues. Zero Sequence Voltage (ZSV) control is proposed for producing balanced power during varying irradiance conditions. The proposed method is simulated using MATLAB SIMULINK software. Partial shading is conquered by using distributed MPPT. Findings: The simulation of the proposed system is performed for a three-phase system. The three-phase Cascaded Modular Multilevel Converter is connected to the grid through two loads which are controlled by a Zero Sequence Voltage Controller. Power quality parameters such as current, harmonics, and power are analyzed for the proposed system. Novelty: THD analysis for a five-level cascaded H bridge converter and the proposed systems are compared and presented. Keywords: Photo voltaic, Cascaded seven-level modular multilevel converter, Zero sequence control, Maximum power point tracking, Voltage Source Converter

Novel modular multilevel matrix converter topology for efficient high-voltage AC-AC power conversion

Introduction. This paper delves into the practical application of multilevel technology, particularly focusing on the capacitor-clamped converter as a promising solution for medium-to-high voltage power conversion, with specific emphasis on direct AC-AC switching conditions. Problem. The limitations of conventional single-cell matrix converters (MC) in efficiency and performance for medium-to-high voltage power conversion applications are well-recognized. Goal. The primary objective is to investigate the performance of the 3 phase modular multilevel matrix converter (3MC) with three flying capacitors (FCs) modeling. This investigation utilizes the Venturini method for gate pulse generation, aiming to compare the performance of the 3MC with standard converter designs. Methodology. To achieve the research goal, the Venturini method is adopted for generating gate pulses for the 3MC, representing a departure from conventional approaches. Detailed simulations employing MATLAB/Simulink are conducted to comprehensively evaluate the performance of the 3MC in comparison to conventional converter designs. Results. The simulation outcomes reveal a significant reduction of 73 % in total harmonic distortion (THD) achieved by the 3MC. This reduction in THD indicates improved robustness and suitability for medium-to-high voltage power conversion systems necessitating direct AC-AC conversion. These results highlight the efficacy of the 3MC in enhancing power conversion efficiency and overall performance. Originality. This paper contributes novel insights into the practical implementation of multilevel technology, particularly within the realm of capacitor-clamped converters. Furthermore, the utilization of the Venturini method for gate pulse generation in the 3MC represents an original approach to enhancing converter performance. Practical value. The research findings present significant advancements in multilevel transformer technology, offering valuable guidance for optimizing transformer design in various industrial and renewable energy applications. These contributions serve to enhance the development of reliable and efficient power systems, addressing critical needs in the energy sector. References 54, tables 3, figures 4.