Renewable Energy Applications Research Articles

A DFT Approach to Insight on the Structural, Optoelectronic and Thermoelectric Properties of Cubic Perovskites YXO3 (X = Ga, In) for Renewable Energy Applications

A DFT Approach to Insight on the Structural, Optoelectronic and Thermoelectric Properties of Cubic Perovskites YXO3 (X = Ga, In) for Renewable Energy Applications

Eminent Red Sea water hydrogen generation via a Pb(ii)-iodide/poly(1H-pyrrole) nanocomposite photocathode

Abstract The development of a photocathode based on a Pb(ii)-iodide/poly(1H-pyrrole) porous spherical (PbI2/P1HP PS) nanocomposite has been successfully achieved in the efficient production of H2 gas from Red Sea water. The distinguishable spherical and porous shapes of these nanocomposites are characterized by a minimum surface measuring approximately 25 nm. This structural configuration, coupled with the nanocomposite’s substantial light absorbance, results in a modest bandgap of 2.4 eV. This turns the nanocomposite into a highly promising candidate for renewable energy applications, particularly for H2 gas generation from natural sources like Red Sea water. The economic viability of the PbI2/P1HP PS nanocomposite, relying on a glass substrate, mass production, and straightforward fabrication techniques, adds to its promising profile for H2 gas evolution. The photocathode exhibits significant potential for H2 gas production, with a notable current density (J ph) value of 1.0 mA·cm−2 in a three-electrode cell configuration. The IPCE reaches 3.1%, reflecting the successful evolution of 24 µmol·h−1 10 cm2 of the photocathode. Importantly, the use of natural Red Sea water as an electrolyte underscores a key feature for H2 gas production: utilizing freely available natural resources. This aspect holds considerable promise for industrial applications, emphasizing the environmentally sustainable nature of the photocathode.

Photocatalytic CO2 Reduction to Solar Fuels by a Chemically Stable Bimetallic Porphyrin-Based Framework.

Porphyrin-based photocatalysts have emerged as promising candidates for facilitating carbon dioxide (CO2) reduction due to their exceptional light-harvesting properties. However, their performance is hindered by complex synthesis procedures, limited structural stability, inadequate CO2 activation capabilities, and a lack of comprehensive structure-property relationships. This study investigates the performance of a porphyrin-based bimetallic framework, [Cu(TPP)Cu2Mo3O11] (TPP = tetrapyridylporphyrin), termed MoCu-1 for photocatalytic CO2 reduction. In addition to its straightforward one-pot synthesis method, the framework shows remarkable chemical stability, particularly notable in alkaline reaction conditions, making it a compelling option for sustainable catalytic applications. By harnessing the superior photoabsorption properties of the porphyrin linker and the abundance of catalytic sites provided by the bimetallic structure, this framework exhibits the potential for enhancing CO2 reduction efficiency. MoCu-1 demonstrates excellent activity in converting CO2 into CO, achieving a maximum yield of 3.21 mmol g-1 with a selectivity of ∼93%. We unravel the intricate interplay of structural features and catalytic activity through systematic characterization techniques and an in situ diffuse reflectance Fourier transform study, which provided insights into the mechanism governing CO2 conversion and was supported by density functional theory calculations. This work contributes to advancing our understanding of photocatalytic processes and offers guidance for designing robust materials for CO2 utilization in renewable energy applications.

Use of Triboelectric Nanogenerators in Advanced Hybrid Renewable Energy Systems for High Efficiency in Sustainable Energy Production: A Review

Renewable energy is the best choice for clean and sustainable energy development. A single renewable energy system reveals an intermittent disadvantage during the energy production process due to the effects of weather, season, day/night, and working environment. A generally hybrid renewable energy system (HRES) is an energy production scheme that is built based on a combination of two or more single renewable energy sources (such as solar energy, wind power, hydropower, thermal energy, and ocean energy) to produce electrical energy for energy consumption, energy storage, or a power transmission line. HRESs feature the outstanding characteristics of enhancing energy conversion efficiency and reducing fluctuations during the energy production process. Triboelectric nanogenerator (TENG) technology transduces wasted mechanical energies into electrical energy. The TENG can harvest renewable energy sources (such as wind, water flow, and ocean energy) into electricity with a sustainable working ability that can be integrated into an HRES for high power efficiency in sustainable renewable energy production. This article reviews the recent techniques and methods using HRESs and triboelectric nanogenerators (TENGs) in advanced hybrid renewable energy systems for improvements in the efficiency of harvesting energy, sustainable energy production, and practical applications. The paper mentions the benefits, challenges, and specific solutions related to the development and utilization of HRESs. The results show that the TENG is a highly potential power source for harvesting energy, renewable energy integration, application, and sustainable energy development. The results are a useful reference source for developing HRES models for practical applications and robust development in the near future.

Investigation on the hydrogen storage properties, electronic, elastic, and thermodynamic of Zintl Phase Hydrides XGaSiH (X = sr, ca, ba)

This study presents a comprehensive investigation of the electronic, mechanical, and thermodynamic properties of Zintl phase hydrides XGaSiH (X = Sr, Ca, Ba) using Density Functional Theory (DFT) and the FP-LAPW method within the WIEN2k package. Our analysis covers the structural stability, electronic properties, and hydrogen interaction mechanisms in these compounds. The hydrides exhibit narrow band gaps, with values ranging from 0.1 to 0.5 eV using GGA and LDA functionals, and 0.6–1.0 eV with mBJ-GGA and mBJ-LDA. The hydrogen storage capacities are determined to be 0.34 wt %, 0.47 wt %, and 0.40 wt % for SrGaSiH, CaGaSiH, and BaGaSiH, respectively, highlighting their potential for energy storage applications. Thermodynamic properties, evaluated through the quasi-harmonic Debye model, provide insights into the Grüneisen parameter, heat capacity, and thermal expansion coefficient over a range of pressures (0–50 GPa) and temperatures (up to 1000 K). Elastic constants reveal that these compounds are mechanically stable, with a notable anisotropy in the {100} plane and varying degrees of compressibility among the different hydrides. Our study further highlights the slightly ordered hexagonal Ga and Si layers, which contribute to the enhanced hydrogen storage capabilities of these materials. The compounds demonstrate high structural stability, facilitating effective hydrogen retention and release at practical temperatures, making them promising candidates for hydrogen storage applications. Additionally, the analysis of electronic band structures and density of states suggests significant conductivity potential, with band gaps ranging from 0.1 to 1.0 eV, depending on the computational method used. The unique combination of structural, electronic, thermodynamic, and mechanical properties in XGaSiH compounds positions them as valuable materials for renewable energy applications. These findings lay the groundwork for future research focused on optimizing these materials through structural modifications or doping to enhance performance metrics such as hydrogen storage capacity and electrical conductivity.

Experimental Study on the Combined Heat Storage and Supply of Air/Water-Source Heat Pumps

As the application of renewable energy becomes increasingly extensive, heat pump technology with renewable energy as the heat source is achieving good results. Air-source heat pumps and water-source heat pumps can be widely used in cold areas. In this work, an integrated combined storage and supply system of an air-source heat pump and a water-source heat pump was studied, and the heating characteristics of the system at the beginning, middle, and end of the heating period were examined. It was found that, when the outdoor temperature of the system was very low, the efficiency of the combined storage and supply system reached the highest value of 2.57 when the source-side water tank was kept at 30 °C, and the performance of the combined storage and supply system was better than that of the air-source heat pump and the water-source heat pump in cold regions. Meanwhile, the independent storage of the air-source heat pump and the combined storage and supply system can be used for heating at the beginning and end of the heating period.

A New Cascaded Multilevel Inverter for Modular Structure and Reduced Passive Components

In high-power applications, achieving adequate power quality in power converter design is accomplished by utilizing multilevel inverters instead of using two-level and three-level inverters. The device generates a sinusoidal output voltage, which results in reduced total harmonic distortion and lower voltage stress on the switches and leads to lower electromagnetic interference, making it suitable for use in renewable energy applications. However, to illustrate the advantages mentioned above, a significant number of switching devices and DC sources are necessary while raising the voltage levels. This article proposes an asymmetrical voltage generation method, which operates in a ratio of 1:5 and generates 25 levels using 11 power switches. The topology is modular in structure, and each module has a lower component count, which significantly reduces the overall cost. The proposed topology is capable of generating negative output voltage levels without the use of an H-bridge configuration, where only three switches are used to generate any voltage levels. The functionality of the developed module is amended by fixing different voltage values in DC sources. This article also presents a comprehensive examination of the circuit and the functioning of various voltage levels. The advantages of the proposed inverter have been demonstrated by comparative research with the currently existing MLI topologies. Ultimately, both the simulation and experimental findings validated the practical capabilities.

A new positive output DC–DC buck–boost converter based on modified boost and ZETA converters

A new DC–DC buck–boost converter with a wide conversion ratio is presented in this paper. The proposed buck–boost converter consists of a combination of modified boost converter and ZETA converter, which has the advantages of both converters such as continuous input/output current and positive polarity of the output voltage. The combination of these two converters achieves semi-quadratic voltage gain and makes the proposed converter suitable for industrial and renewable energy applications. With a voltage gain higher than that of the ZETA converter and modified boost converter, the proposed converter also reduces input current stress due to its continuity. Two operating states are available for this converter in continuous conduction mode. This converter has two switches that operate simultaneously and can be easily controlled. The converter's output voltage ripple and output capacitor current stress are reduced as a result of continuous output current. Computational analysis and the introduced structure efficiency considering the influence of parasitic elements are presented in this paper. The small signal modelling and closed-loop control, as well as simulation and experimental results are also presented. This converter has also been compared with other similar and recently presented topologies. Finally, a 40–60 W, 20–76 V for boost mode and 10 V for buck mode prototype was implemented to verify the accuracy of the computational analysis.

Advancements in Digital Twin Technology and Machine Learning for Energy Systems: A Comprehensive Review of Applications in Smart Grids, Renewable Energy, and Electric Vehicle Optimisation

Advancements in Digital Twin Technology and Machine Learning for Energy Systems: A Comprehensive Review of Applications in Smart Grids, Renewable Energy, and Electric Vehicle Optimisation

Enhancing renewable energy utilization and energy management strategies for new energy yachts

Hydrogen energy, due to its clean and efficient nature, has shown great potential during the current transition period in the shipbuilding industry. However, the application of hydrogen energy in ship energy systems is influenced by variations in operational load and the integration of new energy sources during actual navigation. To address these issues, this paper focuses on optimizing and scheduling the operation of ships under various navigation conditions, considering the distributed nature of hydrogen energy. System simulations were conducted to model the photovoltaic (PV), proton exchange membrane fuel cells (PEMFCs), lithium batteries (LIBs), electrolytic cells (ECs), and energy storage modules of yacht energy systems. Component boundaries and objective functions were set, and two cases (excess photovoltaic state and constant power state) were designed to optimize and regulate the energy balance of hydrogen-powered yachts, enhancing their comprehensive utilization of renewable energy. By comparing the changes in ship energy under the two cases, it was concluded that case 1 ensures the maximum utilization of renewable energy. When photovoltaic power generation is insufficient, the PEMFC and LIB in the system provide the required power to achieve a supply-demand balance. Moreover, when PV power generation is sufficient, hydrogen energy is used to store renewable energy. The optimization method designed in this study can, to some extent, maximize the application of renewable energy in new energy yachts, ensuring the efficiency of the comprehensive energy system of new energy yachts, reducing emissions, and improving the sustainability and economic efficiency of the ships.

A High Step-Up Hybrid Y-Source-Quasi-Z Source DC–DC Converter for Renewable Energy Applications

A High Step-Up Hybrid Y-Source-Quasi-Z Source DC–DC Converter for Renewable Energy Applications

A Current-Fed Transformer-Based High-Gain DC–DC Converter With Inverse Gain Characteristic for Renewable Energy Applications

A Current-Fed Transformer-Based High-Gain DC–DC Converter With Inverse Gain Characteristic for Renewable Energy Applications

A new fault-tolerant converter for renewable energy applications with improved reliability

With power converters consisting of several components, the reliability of a power converter becomes a major concern. With a switched-capacitor (SC) integrated into multilevel inverter (MLI) topologies, the chances of faults is more due to a much larger number of components than the MLI topologies with multiple isolated dc voltage sources. In this article, several SC-based 5L-MLI topologies have been analyzed for their performance with open-circuit fault (OCF), and based on the analysis, three 5L fault-tolerant MLI topologies have been proposed. The analysis for the proposed topologies have been carried out in terms of power loss analysis using PLECS software and power quality analysis using MATLAB software for different fault case scenarios. Further, the proposed 5L topologies have been compared with a similar state-of-the-art. A hardware prototype has been developed, and results have been discussed for various operating conditions.

Artificial Intelligence-Based Improvement of Empirical Methods for Accurate Global Solar Radiation Forecast: Development and Comparative Analysis

Artificial intelligence (AI) technology has expanded its potential in environmental and renewable energy applications, particularly in the use of artificial neural networks (ANNs) as the most widely used technique. To address the shortage of solar measurement in various places worldwide, several solar radiation methods have been developed to forecast global solar radiation (GSR). With this consideration, this study aims to develop temperature-based GSR models using a commonly utilized approach in machine learning techniques, ANNs, to predict GSR using just temperature data. It also compares the performance of these models to the commonly used empirical technique. Additionally, it develops precise GSR models for five new sites and the entire region, which currently lacks AI-based models despite the presence of proposed solar energy plants in the area. The study also examines the impact of varying lengths of validation datasets on solar radiation models’ prediction and accuracy, which has received little attention. Furthermore, it investigates different ANN architectures for GSR estimation and introduces a comprehensive comparative study. The findings indicate that the most advanced models of both methods accurately predict GSR, with coefficient of determination, R2, values ranging from 96% to 98%. Moreover, the local and general formulas of the empirical model exhibit comparable performance at non-coastal sites. Conversely, the local and general ANN-based models perform almost identically, with a high ability to forecast GSR in any location, even during the winter months. Additionally, ANN architectures with fewer neurons in their single hidden layer generally outperform those with more. Furthermore, the efficacy and precision of the models, particularly ANN-based ones, are minimally impacted by the size of the validation data sets. This study also reveals that the performance of the empirical models was significantly influenced by weather conditions such as clouds and rain, especially at coastal sites. In contrast, the ANN-based models were less impacted by such weather variations, with a performance that was approximately 7% better than the empirical ones at coastal sites. The best-developed models, particularly the ANN-based models, are thus highly recommended. They enable the precise and rapid forecast of GSR, which is useful in the design and performance evaluation of various solar applications, with the temperature data continuously and easily recorded for various purposes.

Numerical study on solar heating system with different auxiliary heat sources

In recent years, extensive research has focused on leveraging solar energy as a primary contributor to renewable energy applications, emphasizing the optimization of energy systems tailored to regional demands and resources. This study proposes a solar energy-based heating system and evaluates the impacts of various auxiliary heat sources in Zhengzhou, China (latitude 34.75°). The research evaluates the influence of different auxiliary heat sources on system performance and investigates the optimal tilt and azimuth angles for solar collectors to maximize thermal efficiency. Results indicate that integrating a heat pump as an auxiliary heat source minimizes energy consumption and enhances economic viability. Notably, the optimal tilt angle of the solar collector deviates by approximately 5° from the geographical latitude. Moreover, analysis reveal consistent trends in azimuth and installation angles, particularly when the optimal azimuth angle is 0°, thereby impacting solar collector efficiency.

Effect of sulfidation and phosphidation on Fe doped Co LDH/nickel foam for efficient multifunctional water splitting electrodes, urea oxidation reaction, and seawater splitting: An experimental and computational study

In this work, the binder-free Fe-doped cobalt LDH/nickel foam (CoFe LDH/NF) electrode was prepared using the hydrothermal method. To achieve higher electrocatalyst activity of CoFe LDH/NF, sulfurization was conducted using the hydrothermal method, while the phosphidation was performed through a chemical vapor deposition (CVD) technique. The CoFeS/NF and CoFeP/NF electrodes exhibited significantly higher electrocatalytic activity than CoFe LDH/NF electrode. The CoFeP/NF electrode with a specific surface area of 6.8 m2 g−1 had lower overpotentials of 120 and 236 mV for hydrogen (HER) and oxygen (OER) evolution reactions, respectively. Additionally, the CoFeP/NF electrode exhibited a low potential of 1.32 V vs. RHE at a current density of 10 mA cm−2 for urea oxidation reaction (UOR). The CoFeP/NF electrode demonstrated low overpotentials of 224 and 273 mV in a seawater solution for HER and OER, respectively. The density functional theory (DFT) calculations confirmed the experimental results in which the CoFeP/NF material had promising electrocatalytic activity for renewable energy applications.

Optimizing novel perovskite Mg3AsBr3 through uniaxial stress: a comprehensive study of its potential in solar and optoelectronic applications

This study presents a detailed investigation into optimizing the novel perovskite Mg3AsBr3 through uniaxial stress for enhanced performance in solar and optoelectronic applications. Using Density Functional Theory (DFT), we examined its structural, electronic, and optical properties under uniaxial stress from 0.5 to 5.0 GPa. Key findings include the tuning of the material’s bandgap from 1.485 eV (without stress) to an optimized range closer to 1.13581 eV under 5.0 GPa, demonstrating potential for improved solar cell efficiency. Our findings reveal a nuanced response of the material’s absorption coefficients at critical energies of 2.92 eV and 4.0 eV, where a descending trend with increasing pressure was observed, indicating a plateau at 1.5 GPa and an anomalous increase at 2.5 GPa. This behavior underscores the significance of stress between 2.5 GPa to 5.0 GPa in tailoring the optical responses essential for enhancing solar absorption efficiency in the ultraviolet to visible light range (300–800 nm). Notably, the dielectric constant increased gradually with stress, peaking at 6.003 under 0.5 GPa and slightly diminishing at 5.0 GPa, suggesting enhanced polarization and intrinsic response to electric fields under mechanical stress. Our research highlights the potential of stress engineering in optimizing perovskite materials for renewable energy applications, offering a pathway to high-efficiency, low-cost solar cells.

Investigation of physical properties of Ba2NdX(X=Nb, Ta)O6 double perovskites for renewable energy applications

Alkali metals at the A site, coupled with rare earth transition metals featuring partly filled 4f and d orbitals at B and B’ sites in A2BB’O6 structure of double perovskites, induce complex d-f electron interactions. Present study explores the rare earth-based double perovskites Ba2NdNbO6 and Ba2NdTaO6, investigating their structural, optoelectronic, magnetic, and thermoelectric characteristics using first principles method. Computational analyses confirm the stable cubic symmetry and ferromagnetic ground state of both compounds. Negative formation enthalpies underline their thermodynamic stability. Spin polarized electronic band structures reveal direct–indirect degeneracy near the Fermi level, dominated by Nd-4f electrons. Optical investigations indicate absorption onset edges at 4.0 eV and significant absorbance peaks in the 6–10 eV range. Furthermore, the investigation into thermoelectric figure of merit reveals capability of Ba2NdNbO6 and Ba2NdTaO6 to efficiently convert heat energy in thermoelectric devices. These findings provide information for potential applications of investigated compounds in thermoelectric (TE) and optoelectronic devices; e.g., in optical absorbers, TE coolers and generators, and photonic devices.

Study of promising lithium-based lead-free double perovskites Li2AuBiX6 (X = Cl, Br, and I) for optoelectronic and other renewable energy applications

The current study effort primarily focuses on the computational investigation of the physical properties of Li2AuBiX6 (X = Cl, Br, and I) double perovskites (DPs) utilizing the Density Functional Theory (DFT) framework. The structural and elastic characteristics have been evaluated to reveal phase and mechanical stability. The assessed formation energy and elasticity constants calculations validate that the examined DPs possess cubic phase, exhibit stability, and demonstrate ductility. The band structure analysis has been accomplished with a modified Becke-Johnson (mBJ) potential. Theband structure simulations reveal that Li2AuBiCl6, Li2AuBiBr6, and Li2AuBiI6 possess an indirect energy gap, with values of 1.12 eV, 0.77 eV, and 0.084 eV, respectively. We further examined the optical parameters in the spectrum of incoming photons from 0 to 4 eV. Considerable absorbance in the visible spectrum has been observed for Li2AuBiX6 (X = Cl, Br, and I), suggesting that these DPs are compatible with photovoltaics. Finally, we have computed thermoelectric (TE) characteristics in relation to temperatures within the range of 100 to 600 K. The investigated DPs might be suitable for thermoelectric systems, as indicated by the moderate values of the figure of merit, which needs to be improved. The obtained absorption and figure of merit values surpass similar perovskites Rb2AuBiX6. Hence, the current work might be advantageous for developing novel photovoltaic and TE systems.

A theoretical analysis of the effect of hydrostatic pressure on cerium oxide for renewable energy applications

The characteristics of cubic cerium oxide (CeO2) have been investigated using density functional theory (DFT) using the PBE-GGA exchange–correlation functional. This study mainly focused on the structural, elastic, and optoelectronic properties of the CeO2 under the application of external hydrostatic pressure. It is observed that lattice constants and volume tend to decrease with increasing pressure. Based on the observed trends in lattice constants variations, CeO2 exhibits compressibility at high-pressure conditions, although it remains structurally unchanged throughout the pressure range of 0 to 100 GPa. Applying pressure within the range of 0 to 100 GPa reveals a distinct characteristic associated with the emergence of electronic bandgap opening. The material displays an indirect energy bandgap, with its magnitude increasing from 2.659 eV to 4.055 eV under rising pressure. To deeply understand the impact of external pressure on the optical behaviour of CeO2, extensive investigation has been conducted on several optical parameters such as the dielectric function, refractive index, optical reflectivity, absorption coefficient, optical conductivity, and loss function throughout the energy range up to 50 eV. However, there is a tendency for optical parameters to show sharpening peaks that shift somewhat towards higher energies. Furthermore, we have also tested the impact of bandgap modulation induced in CeO2 by proposing a CsSnBr3-based solar cell with the One-Dimensional Solar Cell Capacitance Simulator software. Based on our findings, the use of cubic cerium oxide may find its potential to enhance the performance of optoelectronic and renewable energy devices.