Photovoltaic-thermoelectric System Research Articles

Theoretical and experimental analyses and optimizations of direct coupling photovoltaic-thermoelectric systems

A photovoltaic-thermoelectric (PV-TE) system is modeled theoretically and demonstrated experimentally. Mathematical formulations of the system are proposed according to energy conservation and finite-time thermodynamics, which can be applicable to analyze and optimize the system that consists of commercial photovoltaic (PV) cells and thermoelectric generators (TEGs). The genetic algorithm is introduced to maximize the system's power by optimizing multiple parameters. In Yan'an City, which is located in the northern Shaanxi Province in northwest China, the actual solar irradiance is recorded for almost a full year and the proposed model is verified. Theoretical and experimental results are analyzed and compared. It is found that there are several independent structure parameters in the PV-TE systems and they should be optimized simultaneously to maximize the performance. The PV-TE system's maximum theoretical average power of 0.343 W is 2.69 % greater than the solo PV cell's maximum theoretical power of 0.334 W. The measured average power of the system of 0.317 W is 0.32 % more than that of a solo PV cell of 0.316 W. The duration of strong lighting in Yan'an City reaches 8 h every day for nearly one year and the irradiation intensity can approach 1000 W/m2. The solar radiance is weakly affected by the seasonal changes of four seasons but is greatly affected by rainy days and cloud thickness. The research findings can serve as a helpful guide for the specific implementation of the PV-TE system and exploitation of solar energy resources in northwest China.

Three-objective optimization of a concentrated photovoltaic thermoelectric system via student psychology-based optimization algorithm and an external archive strategy

Thermoelectric generators (TEGs) present a promising avenue for capturing waste heat from photovoltaic (PV) panels in a hybrid concentrated photovoltaic thermoelectric (CPV-TE) setup. However, advancements in CPV-TE technology, especially in optimizing design parameters, remain crucial. A comprehensive thermodynamic analysis reveals non-monotonic, coupling influences of design factors on system performances. In light of this, we tackle a multi-criteria optimization problem using the Student Psychology-Based Optimization (SPBO) algorithm with an external archive strategy. This approach successfully identifies a range of alternative (Pareto frontier) solutions in a three-objective optimization scenario. Results indicate that setting grid density and repertoire number to 10 and 100, respectively, ensures both excellent convergence and computational efficiency. Further, the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) method aids in selecting an energy-efficient solution from the Pareto frontier. In an efficiency-oriented strategy, total output power, overall efficiency, and TEG power generation stand at 491.32 W, 10.85 %, and 15.91 W, respectively. Conversely, prioritizing total power output yields figures of 540.9 W, 9.61 %, and 26.35 W, respectively.

Performance optimization of nanofluid-cooled photovoltaic-thermoelectric systems: A study on geometry configuration, steady-state and annual transient effects

In this study, we explored Photovoltaic-Thermoelectric (PV-TE) systems in-depth, addressing complexities in both steady-state and annual transient performance under realistic conditions. The analysis involved twelve distinct PV-TE configurations featuring diverse thermoelectric designs incorporating various semiconductors, multi-staging, non-uniform cross-sections, and material segmentation. Model 6, the PV-TE system with a multi-stage segmented rectangular design, emerged as the top performer, exhibiting a remarkable 12% increase in electric power output during peak sunlight compared to the base model, despite a marginal decrease in efficiency. Furthermore, this research delved into the potential of advanced nanofluid cooling, investigating options such as distilled water, titanium oxide, aluminum oxide, iron oxide, and graphene. The results underscores graphene nanofluid's superiority, demonstrating a significant enhancement in thermal management at an optimal flow velocity of 2 m/s. This improvement in thermal management refers to the effective heat dissipation and temperature control within the PV-TE system. This study underlines the critical role of strategic system design and component selection in optimizing the performance of PV-TE systems. By providing a comprehensive foundation for future developments in effective and sustainable energy solutions, this research contributes to advancing the understanding and implementation of PV-TE technology.

Thermodynamic analysis of a spectrum splitting photovoltaic-thermoelectric system with a multi-physics coupling process

Quantifying the losses in the various energy transfer and conversion processes is essential for the study and application of the spectrum splitting photovoltaic-thermoelectric system because of the complex system structure. This paper develops a novel optical-electrical-thermal multi-physics coupling model for the spectrum splitting photovoltaic-thermoelectric system that correlates microstructure and macroscopic properties. Based on the multi-physics coupled model, a thermodynamic analysis method is employed to reveal the distributions of energy and exergy losses in the system, and the effect of the concentration ratio on the losses is investigated. The results show that the optical loss caused by the concentrating and splitting processes accounts for 33.3% of the total input energy. The losses in the energy conversion process are the largest of all the subsystem losses. The energy and exergy losses in the photovoltaic conversion process are 51.5% and 45.9%, while those for the thermoelectric conversion process are 87.8% and 74.5%, respectively. Raising the concentration ratio is an effective way to reduce the exergy loss in the energy conversion process, but it will also partially raise the exergy losses in the heat dissipation and cooling processes. The exergy efficiency of the SSPV-TE system can reach 21.75% at a concentration ratio of 500. The results are important for better understanding the operating principles, optimizing the performance, and advancing the application of the spectrum splitting photovoltaic-thermoelectric system.

Latest Advancements in Solar Photovoltaic-Thermoelectric Conversion Technologies: Thermal Energy Storage Using Phase Change Materials, Machine Learning, and 4E Analyses

In recent times, the significance of renewable energy generation has increased and photovoltaic-thermoelectric (PV-TE) technologies have emerged as a promising solution. However, the incorporation of these technologies still faces difficulties in energy storage and optimization. This review paper addresses these challenges by providing a comprehensive overview of the latest advancements in PV-TE technologies. The paper emphasizes the integration of phase change materials (PCMs) for thermal energy storage, also buttressing the use of encapsulated PCM for thermal storage and efficiency, and the use of hybrid PCM to enhance overall performance. Furthermore, reviews on the use of machine learning techniques for efficient optimization and the integration of thermoelectric modules into tandem perovskite silicon solar cells have been comprehensively analyzed. The advancements in photovoltaic-thermoelectric systems, as reviewed in this article, signify significant progress in attaining sustainable and effective energy production and storage. This review comprehensively addresses the 4Es, underlining their importance. It not only consolidates recent developments but also charts a path for future research in the field of PV-TE technologies, offering precise insights to guide upcoming studies and innovations.

Role of Quantum Dots and Nanostructures in Photovoltaic Energy Conversion

Nanostructures and quantum dots have substantial effects on enhancing photovoltaic energy conversion efficiency, as evidenced in this comprehensive study. Materials that are nanostructured and nanosized particles are commonly used to address the urgent issues related to energy conversion. The use of nanostructured substances to address issues with energy and natural resources has garnered a lot of interest lately. Directional nanostructures in particular show promise for the conversion, collection, and storage of energy. Due to their unique properties, such as electrical conductivity, mechanical energy, and photoluminescence, quantum dots made from carbon (CQDs) and graphene quantum dots (GQDs) have been integrated into hybrid photovoltaic-thermoelectric systems (PV-TE). It evaluates the effects of nanostructures on solar energy technologies, in particular how they can improve power conversion and light absorption in solar cells. Optical light detectors, which transform photonic energy into signals that are electrical, are among the many optoelectronic uses of CQDs that have drawn attention because they are essential components of contemporary imaging and communication systems, such as visible light cameras, machine vision, medical X-ray and near-infrared image processing, and visible light detection devices. Besides supercapacitors, the study investigates how nanostructures could play a crucial role in contributing to addressing the global energy crisis sustainably, by working as photocatalysts for hydrogen synthesis and supercapacitors.

Investigation of solar photovoltaic-thermoelectric system for building unit in presence of helical tapes and jet impingement of hybrid nanomaterial

Solar photovoltaic must be equipped with a cooling unit to gain thermal performance and in present research, a new configuration of unit for photovoltaic-thermal has been presented. To enhance the electrical performance, a thermoelectric layer has been attached above the absorber. Two regions for hybrid nanofluid flow exist within the system including a circular duct equipped with a turbulator and mini channel equipped with jet impingement. The regimes of both zones are laminar and single phase formulation for properties of hybrid nanomaterial has been utilized. With selecting the turbulator with the greatest level of revolution, the electrical efficiency enhances about 1.41% and useful heat enhances about 5.72%. The amount of performance factor for the case with highest revolution is 1.25 which means the good hydrothermal performance. The mentioned case has been equipped with confined jets and the amount of electrical and thermal performance of the best case reaches 15.50% and 85.30%. The temperature uniformity of the new design improves about 46.89%.

A novel thermosyphon cooling applied to concentrated photovoltaic-thermoelectric system for passive and efficient heat dissipation

Concentrated photovoltaic-thermoelectric systems have received extensive research attention as a means of enhancing the utilization rate of solar energy. However, the expedited progress of these systems has been hindered by a myriad of challenges, such as the additional power consumption required for active cooling and the inadequate cooling rates of conventional passive cooling techniques. To overcome these limitations, a novel concentrated photovoltaic-thermoelectric system integrating thermosyphon cooling has been developed and subjected to a comprehensive analysis, encompassing its start-up performance, pipe resistance characteristics, and power generation performance have been analyzed. The results reveal that the buoyancy generated by the thermosyphon is 8.22 N, which effectively drives the speed of cooling water circulation to 0.011 m/s. The start-up time of the thermosyphon effect lengthens gradually with a decrease in inclination angle of heat sink, while the cooling temperature at the final stable state remains relatively consistent. Remarkably, at 240 kW/m2, the concentrated photovoltaic cell exhibits a remarkable heat dissipation power density of 15.26 W/cm2. Meanwhile, the optimal output voltage of concentrated photovoltaic is 1.907 V, at which the concentrated photovoltaic output power is 1.774 W. The optimal output voltage of thermoelectric is 0.528 V, at which the thermoelectric output power is 0.054 W. The results provide guidance for designing high-performance cooling systems for concentrated photovoltaic-thermoelectric systems.

Energy, exergy, economic, and environmental (4E) analyses of bifacial concentrated thermoelectric-photovoltaic systems

A concentrated photovoltaic-thermoelectric (CPV-TE) system could utilise the full solar spectrum for electrical energy generation. However, the output performance of the conventional CPV-TE system is low due to the high thermal resistance associated with the TE module that raises the surface temperature of the PV. This study presents comprehensive energy, exergy, economic, and environmental (4E) analyses of two conventional unifacial CPV-TE models and two bifacial CTE-PV models. The bifacial models receive solar energy from two directions. The results reveal that at a concentration ratio of 60, the highest electrical energy and exergy efficiencies of 32% and 35%, respectively, are obtained from the bifacial concentrated segmented thermoelectric-heat sink-photovoltaic (CSTE-HS-PV) model. The annual CO2 savings due to the energy generated by the CSTE-HS-PV, CTE-HS-PV, and CPV-HS-TE are 202 kg/year, 119 kg/year, and 13 kg/year, respectively. Moreover, the payback period (PBP) of the CSTE-HS-PV, CTE-HS-PV, and CPV-HS-TE models are 8.4 years, 10.5 years, and 45 years, respectively. Finally, the levelized cost of energy (LCOE) of the CSTE-HS-PV, CTE-HS-PV, and CPV-HS-TE models are 0.36 $/kWh, 0.55 $/kWh, and 5.06 $/kWh, respectively. Based on the 4E analysis, the CSTE-HS-PV model is found to be superior to the other state-of-the-art models.

Comparative analysis of photovoltaic thermoelectric systems using different photovoltaic cells

The photovoltaic-thermoelectric (PV-TE) system has emerged as a focal point in research endeavors aimed at harnessing the full spectrum of solar energy and enhancing the efficacy of solar power generation. Owing to the variations in bandgap and inherent material properties across diverse photovoltaic cells, the capacity to utilize the solar spectrum of PV-TE systems can be significantly affected when using different photovoltaic cells. Historically, investigations into the influence of photovoltaic cells on PV-TE systems have been predominantly rooted in theoretical simulations. These examinations have primarily concentrated on the holistic system efficiency under varying temperature conditions. In this study, we integrated three distinct types of photovoltaic cells into PV-TE systems. Both simulation and experimental methodologies were employed to evaluate the impact of these photovoltaic cell types on the PV-TE systems' performance. Additionally, we compared the back temperatures of standard PV systems with those of PV-TE systems. The average photovoltaic conversion efficiencies of PV-TE systems equipped with CIGS, CdTe, and a-Si photovoltaic cells were 21.9%, 19.7%, and 12.7%, respectively. Meanwhile, the average efficiencies of TEG were 0.256%, 0.102%, and 0.083% respectively, with average backplate temperatures of 39.3 °C, 44.0 °C, and 40.5 °C. The temperature disparities between the back of standard photovoltaic systems and PV-TEG-PCM systems stood at 4.70 °C, 2.32 °C, and 3.43 °C, respectively. Notably, CIGS photovoltaic cells, which harness a specific range of the solar spectrum more effectively, showcased superior performance. Furthermore, a broader usable solar spectrum band for a PV cell doesn't always translate to enhanced performance. These findings offer valuable insights for optimizing the power generation capabilities of photovoltaic-thermoelectric systems leveraging full-spectrum solar energy.

High-efficiency dynamic lossless coupling of a spectrum splitting photovoltaic-thermoelectric system

Photovoltaic and thermoelectric devices are commonly electrically separated in the spectrum splitting photovoltaic-thermoelectric (SSPV-TE) system because of their distinct output characteristics, resulting in increased system investment and hindering practical application. In this paper, the concept of high-efficiency dynamic lossless coupling of the SSPV-TE system is proposed. A novel electrical-thermal co-design method is provided to achieve high-efficiency dynamic lossless coupling of the SSPV-TE system. The economics of both the electrically separated and series lossless coupling systems are also evaluated. The results indicate that matching the maximum power current of the photovoltaic and thermoelectric devices and weakening the thermoelectric Peltier effect are effective ways to achieve the series lossless coupling. With the electrical-thermal co-design, the hot end of the thermoelectric devices can operate at the allowable temperature of 800 K, and the power difference between the electrically separated and series systems is less than 4 mW. The series system achieves the same average power and efficiency of 1.03 W and 22.48% as the electrically separated system under one-day varying solar irradiation, demonstrating that the high-efficiency dynamic lossless coupling is achieved. The cost of the series system is 4.75 $/W, while that of the electrically separated system is 5.29 $/W. The cost of the SSPV-TE system can be reduced by 10.21% by implementing the series dynamic lossless coupling.

RETRACTED: A prediction model for the performance of solar photovoltaic-thermoelectric systems utilizing various semiconductors via optimal surrogate machine learning methods

RETRACTED: A prediction model for the performance of solar photovoltaic-thermoelectric systems utilizing various semiconductors via optimal surrogate machine learning methods

Multiobjective Optimization and Machine Learning Algorithms for Forecasting the 3E Performance of a Concentrated Photovoltaic-Thermoelectric System

Previous theoretical research efforts which were validated by experimental findings demonstrated the thermo-economic benefits of the hybrid concentrated photovoltaic-thermoelectric (CPV-TE) system over the stand-alone CPV. However, the operating conditions and TE material properties for maximum CPV-TE performance may differ from those required in a standalone thermoelectric module (TEM). For instance, a high-performing TEM requires TE materials with high Seebeck coefficients and electrical conductivities, and at the same time, low thermal conductivities ( k ). Although it is difficult to attain these ideal conditions without complex material engineering, the low k implies a high thermal resistance and temperature difference across the TEM which raises the PV backplate’s temperature in a hybrid CPV-TE operation. The increased PV temperature may reduce the overall system’s thermodynamic performance. To understand this phenomenon, a study is needed to guide researchers in choosing the best TE material for an optimal operation of a CPV-TE system. However, no prior research effort has been made to this effect. One method of finding the optimum TE material property is to parametrically vary one or more transport parameters until an optimum point is determined. However, this method is time-consuming and inefficient since a global optimum may not be found, especially when large incremental step sizes are used. This study provides a better way to solve this problem by using a multiobjective optimization genetic algorithm (MOGA) which is fast and reliable and ensures that the global optimum is obtained. After the optimization has been conducted, the best performing conditions for maximum CPV-TE energy, exergy, and environmental (3E) performance are selected using the technique for order performance by similarity to ideal solution (TOPSIS) decision algorithm. Finally, the optimization workflow is deployed for 7000 test cases generated from 10 features using the optimal machine learning (ML) algorithm. The result of the optimization chosen by the TOPSIS decision-making method generated an output power, exergy efficiency, and CO2 saving of 44.6 W, 18.3%, and 0.17 g/day, respectively. Furthermore, among other ML algorithms, the Gaussian process regression was the most accurate in learning the CPV-TE performance dataset, although it required more computational effort than some algorithms like the linear regression model.

Photothermal Conversion of Solar Infrared Radiation by Plasmonic Nanoantennas for Photovoltaic-Thermoelectric Hybrid Devices

Photovoltaics have become one of the low-cost options for electricity generation. However, the lack of absorption of the near-infrared and infrared solar spectrum intrinsically limits its efficiency. Here, we present an approach for photothermal conversion of solar infrared radiation in photovoltaic-thermoelectric systems using plasmonic nanoantennas. Through numerical calculations-driven shape engineering, we identified Ni diabolo nanoantennas as efficient solar infrared spectrum harvesters. Nanofabrication with electron-beam lithography further revealed its impact on nanoantenna optical properties at the single-nanoantenna level. In the large-scale low-cost approach, however, photothermal surfaces of nanocone plasmonic antennas, made with a simple and robust fabrication process, still deliver a significant 6.1 °C temperature increase under solar infrared illumination. The reported results pave the way toward the development of hybrid photovoltaic-thermoelectric systems with an optimal utilization of the solar spectrum.

Higher conversion efficiency for combined systems with triple-junction GaAs photovoltaic cell and thermoelectric device

Photovoltaic (PV) and thermoelectric (TE) hybrid systems have the potential to increase solar energy utilization and possess broad development prospects. However, it is critical to select a suitable PV cell to couple with TE device and improve the efficiency of the photovoltaic–thermoelectric (PV-TE) hybrid system. This study used thermal interface materials (TIMs) with different thermal conductivities in triple-junction InGaP/GaAs/GeInG (tj-GaAs) PV-TE hybrid systems to reduce thermal contact resistance (TCR). The performance was investigated using a solar simulator with adjustable irradiation intensity and a liquid cooling device with controllable temperature. A comparative study has also been conducted with mono-crystalline (mc-Si) PV-TE system of the similar structure. The results indicated that the total output power of the direct contact PV-TE hybrid device and the optimized hybrid device using a thermal grease with a conductivity of 5.8 W m−1 K−1 could increase by 5.50% and 16.24%, respectively, compared with that of the pure PV. Moreover, lower cooling water temperatures have improved the performance of both PV cell and TE device. Results also indicated that the output power produced by the PV cell and TE device in the tj-GaAs PV-TE system are 537 mW and 0.76 mW higher than that produced by the PV cell and TE device in mc-Si silicon PV-TE system at 3.5 suns and 20 °C cooling water temperature, respectively. Compared to mc-Si PV cells, GaAs PV cells are more suitable for PV-TE hybrid systems and more adaptable under concentrated light conditions.

MODEL DEVELOPMENT AND PERFORMANCE IMPROVEMENT OF A PHOTOVOLTAIC-THERMOELECTRIC SYSTEM BY INTEGRATING AND OPTIMIZING PHASE CHANGE MATERIALS

Integrating phase change materials (PCMs) with concentrated photovoltaic-thermoelectric (PV-TE) systems can effectively control the interface temperature between PV and TE components and improve the full solar-spectrum utilization efficiency. However, since the structure of photovoltaic-phase change material-thermoelectric (PV-PCM-TE) systems is complex and the temperatures among the components are coupled and affect each other, the photo-thermal-electric conversion characteristics under the actual physical properties need to be analyzed by a more detailed model, and the suitable operating conditions for PV-PCM-TE systems remain clear. There is still a lack of the method for improving the system performance. Therefore, a three-dimensional transient model is established herein by combining the Monte Carlo ray-tracing method and finite volume method to simulate the complex energy conversion processes of the PV-PCM-TE system. Based on this, performances of PV-PCM-TE, PV-TE, and PV systems are compared under different operating conditions, and the applicable conditions for PV-PCM-TE systems are analyzed. Then effects of key parameters of the phase change module are investigated. In the end, to further improve the system performance, a partition screening method of PCM is proposed considering the nonuniform solar radiation on photovoltaic surfaces, and the selection and layout area of PCMs are optimized. The results present that the applicable operating conditions are low concentration ratio (< 20) and low heat transfer coefficient (< 20 W·m<sup>-2</sup>·K<sup>-1</sup>). In terms of structural parameters, the system power generation is most significantly affected by the width. In terms of PCM physical properties, it is most affected by the PCM density, followed by latent heat. For different concentration ratios, there are different optimal melting points to achieve the highest power generation. The proposed PCM partition screening method can efficaciously control PV-TE interface temperature, and reduce photovoltaic cells' temperature by 47°C. The system efficiency can be increased by 4.8% and 4.2% after the optimization compared with that of the single PV cell and the traditional PV-TE system, respectively.

Evaluation of the phase change material in regulating all-day electrical performance in the PV-MCHP-TE system in winter

Previous studies on the photovoltaic-thermoelectric (PV-TE) system have focused on its daytime performance, that is, photovoltaic (PV) and thermoelectric generators (TE) only output electricity by day. Consequently, in this paper, a PV-TE system with micro-channel heat pipe (MCHP) and phase change material (PCM) (the PV-MCHP-TE system with PCM) is proposed, and the performance change of the system in 24 h is investigated, which is not involved in earlier researches. Where, PCM on one hand reduces the operating temperature so improves the PV performance in the daytime, and on the other, releases the stored heat to TE at night, which offers a prerequisite for TE to generate power in the nighttime. The mathematical model of the novel system is given out, and its all-day performance is compared with the system without PCM. Theoretical investigations find that PCM improves the overall electrical performance, both in the daytime and the nighttime, with their all-day total outputs of 2.67 × 103 kJ and 2.64 × 103 kJ, respectively, under certain conditions. Additionally, the performance of the two systems under different parameters is further explored, which points out the direction for the following research and also provides valued references for the implementation of integration to PV and TE.

Research and numerical analysis on performance optimization of photovoltaic-thermoelectric system incorporated with phase change materials

In recent years, photovoltaic (PV) cells have been widely used to cope with the problem of global energy shortage. In the current researches, the PV-TEG-PCM (photovoltaic-thermoelectric generator-phase change material) system can improve the utilization of solar energy and the hybrid system shows better performance. Most of the previous studies were two-dimensional models or steady-state models, which could not accurately evaluate the system performance under fluctuating solar irradiation. This research constructs a three-dimensional thermal simulation transient model of the PV-TEG-PCM system. The model is simulated under fluctuating solar irradiation, model validity has been verified. This research completes and optimizes the theoretical researches of PV-TEG-PCM systems. This research will play a guiding role in the subsequent practical experiments and applications. The effects of PCM melting temperature, thickness and thermal conductivity are studied. The results show that the performance of PV-TEG-PCM system is better than that of PV-TEG or sole PV systems. At the peak sun-hour, the PV temperature was reduced for three types of PV-TEG-PCM systems compared to PV-TEG systems. Through simulation, the PCM layer with 30 mm thickness and melting temperature of 42 °C, can make the PV-TEG-PCM system established this time achieve the best thermal performance.

Structure parameter analysis and optimization of photovoltaic-phase change material-thermoelectric coupling system under space conditions

Phase change material (PCM) as highly efficient temperature control material has been used in terrestrial photovoltaic-thermoelectric (PV-TE) coupling system to achieve higher power generation efficiency. However, the mass increase results from addition of PCM limits its application in space system. In present paper, a two-dimensional model for PV-PCM-TE coupling system was developed to investigate the energy transfer and conversion performance under space conditions. Firstly, the suitable PCM was selected, both the pure PCM and its metal foam composite PCM (MFCPCM) are used. Then, performance comparison for PV-TE, PV-PCM-TE and PV-MFCPCM-TE systems were performed. The results show PCM can significantly enhance the total efficiency, but causes power density dramatically decreasing. The average total efficiencies for PV-TE, PV-PCM-TE and PV-MFCPCM-TE are 29.50%, 30.50% and 30.61%, and the corresponding average power density are 30.34 W/kg, 22.39 W/kg and 21.20 W/kg, respectively. After that, an orthogonal experiment was designed to reveal the effects of structure parameters on power generation efficiency and power density of PV-MFCPCM-TE system. The optimum geometric parameters to achieve the best power generation efficiency and power density were derived. The results show that after optimization, the average total efficiency and power density of PV-MFCPCM-TE are 30.83% and 31.35 W/kg, both of them are higher than those of the traditional PV-TE system (29.50% and 30.34 W/kg). The present work is beneficial for the application of PV-PCM-TE system in space conditions.

Accurate prophecy of photovoltaic-segmented thermoelectric generator’s performance using a neural network that feeds on finite element-generated data

To further enhance the photovoltaic–thermoelectric system efficiency, this paper proposes a new hybrid system design comprising a segmented thermoelectric generator and aluminum heat sink directly lapped to the back plate of a photovoltaic cell operating under Nigerian transient and fluctuating weather conditions. The performance evaluation and optimization of the hybrid system design is conducted using a numerical model setup in ANSYS software and the optimized parameters include the thermoelectric leg height and cross-sectional area, skutterudite content, ceramic height, fin and fin base heights, convective film coefficient, and solar concentration ratio while the performance indices are the system power generation rate and the system efficiency. Finally, a Bayesian regularized artificial neural network with 10 neurons in the hidden layer is proposed to overcome the lengthy computational time and energy needed to conduct the numerical-inspired system optimization. Results are that the proposed system design improved the efficiency of the conventional photovoltaic cell integrated with regular unsegmented thermoelectric generators by 96% at a solar concentration of 5. Additionally, the numerical-inspired optimization was able to improve the conventional system power output and efficiency by 45.7% and 45.9%, respectively, compared to the unoptimized system when operated under peak sunshine conditions. Finally, the Bayesian regularized neural network with a low mean squared error of 9.7 × 10−14 after 471 iterations and perfect regression correlations for training, testing, and all processes provided a perfect fit of the numerical-generated data, being 201 times faster than the conventional numerical optimization scheme.