Photovoltaic Thermal System Research Articles

Efficiency upgrading of solar PVT finned hybrid system in Bangladesh: Flow rate and temperature influences

This research aims to determine the impact of mass flow rate and inflow temperature on the utility and effectiveness of solar thermal systems using fins with air in various applications in Bangladesh. This study examines a three-dimensional (3D) photovoltaic thermal (PVT) system where we analyze the behavior of a hybrid system with six aluminum sheets (1 mm thick fin as a heat exchange material) inside the heat exchanger where the air takes the direction to pass in waveform through the channels (made of aluminum) using fins. The top side of the fins is bent and affixed to the bottom of the floor of the PV panel to allow heat transfer utilizing the conduction-based method. This study selects inlet fluid mass flow rate and inflow temperature between (0.015–0.535 kg/s), and (10–40 °C) respectively, while comparing the result with experimental/numerical published data based on Bangladesh's weather conditions and applies the finite element method (FEM) to solve heat transfer equations. A brief analysis of the association among Reynolds number with pressure drop and fanning friction factor is included in this paper. Our model can be mounted on building rooftops or open fields where air velocity will be controlled mechanically; thus, it has many applications. This model can be implemented within an agricultural photovoltaic (APV) system, domestic functions, dry agricultural products, and provide heat for greenhouses. The result indicates that 302–514 W thermal energy has been produced for 0.015–0.535 kg/s. For growing inflow temperature, despite the reduction in electrical efficiency, the value of adding electrical and thermal efficiency (overall efficiency) comes with elevation. A 5 °C increase in inflow temperature leads to an overall efficiency increase of 0.33%. This study's findings can help researchers better comprehend air's properties as a heat exchanger in a developed design, and they can be applied to government and commercial projects.

Recent techniques for cooling of concentrated photovoltaic thermal systems

Recent techniques for cooling of concentrated photovoltaic thermal systems

Numerical modeling and optimization of tube flattening impacts on the cooling performance of the photovoltaic thermal system integrated with phase change material

In this research, a computational fluid dynamics-based numerical simulation is performed to evaluate the influence of tube flattening on the cooling performance of a photovoltaic thermal system integrated with phase change material. Such a study is executed to obtain the four evaluation parameters, including average photovoltaic panel temperature, phase change material melting percentage, tube pressure drops, and the difference between the highest and lowest temperature points on the photovoltaic panel. To obtain the optimum percentage of tube flattening to optimize the cooling performance of the systems, multi-objective optimization by utilizing response surface methodology is done by considering some design requirements, including minimizing average photovoltaic panel temperature, maximizing phase change material melting percentage, minimizing tube pressure drops, and minimizing the difference between the highest and lowest temperature points on the photovoltaic panel. Finally, a parametric analysis is done to explore how certain critical factors (solar radiation, fluid mass flow rate, phase change material thermal conductivity, phase change material enthalpy of fusion, and phase change material melting point) affect the efficiency of the systems. The findings indicate that as tube flattening rises from 0 % to 75 %, the average photovoltaic panel temperature and the difference between the highest and lowest temperature points on the photovoltaic panel decrease which is a positive effect. Conversely, increasing the tube flattening results in an increase in the tube pressure drops and a reduction in the phase change material melting percentage. These changes adversely affect the cooling performance. Considering these impacts and conducting an optimization process, the ideal tube flattening value is 54.78 %. In this optimized state, the average photovoltaic panel temperature reaches 55.21 ˚C, phase change material melting percentage comprises 42.54 %, tube pressure drops is 184.8 Pa, and the difference between the highest and lowest temperature points on the photovoltaic panel is 33.42 ˚C.

Boosting thermal regulation of phase change materials in photovoltaic-thermal systems through solid and porous fins

This study explores the integration of porous fins with phase-change materials (PCM) to enhance the thermal regulation of photovoltaic-thermal (PVT) systems. Computational simulations are conducted to evaluate the impacts of different porous fin configurations on PCM melting dynamics, PV cell temperatures, and overall PVT system effectiveness. The results demonstrate that incorporating optimized porous fin arrays into the PCM region can significantly improve heat dissipation away from the PV cells, enabling more effective thermal control. Specifically, the optimized staggered porous fin design reduces the total PCM melting time and decreases peak cell temperatures by about 5°C . This is achieved by creating efficient heat transfer pathways that accelerate the onset of natural convection during the PCM melting process. Further comparisons with traditional solid metallic fins indicate that while solid fins enable 12.2% faster initial melting, they provide inferior long-term temperature regulation capabilities compared to the optimized porous fins. Additionally, inclining the PV module from 0° to 90° orientation can further decrease the total PCM melting time by 13 minutes by harnessing buoyancy-driven convection. Overall, the lightweight porous fin structures create highly efficient heat transfer pathways to passively regulate temperatures in PVT systems, leading to quantifiable improvements in thermal efficiency of 16% and electricity output of 2.9% over PVT systems without fins.

Performance analysis of a novel façade-based building integrated photovoltaic-thermal system with phase change material for domestic hot water

Since the current contribution of solar thermal energy to the amount of energy consumed for domestic hot water in buildings worldwide is very low (8.4 %, approximately), the potential of this renewable energy to meet the demand for domestic hot water is quite significant. In this context, this paper presents a new façade-based building integrated photovoltaic-thermal system with phase change material which has been patented recently. It is a modular device for installation on façades and roofs, enabling the production of domestic hot water and electricity using solar energy. The main novelty of the system lies in the use of a photovoltaic glass sheet, which improves the building’s aesthetics and facilitates the architectural integration of this type of devices. Thus, a photovoltaic glass is used for the production of electricity, a phase change material for heat storage and a water-phase change material exchanger for the production of domestic hot water. The design and verification stages of the system were developed for a case study under typical usage conditions. Two dimensional numerical models of five different configurations (of the energy harvesting and storage module and two dimensional and three dimensional numerical models of the finned exchanger were carried out to simulate the charge and discharge processes. The most suitable configuration of the system, characterised by a 12 mm vacuum gap and a low emissivity of the absorber, was able to meet the requirements in terms of water flow rate and supply temperature (45 °C) for a shower time of 5 min.

Assessing the environmental health and safety risks of solar energy production

Solar energy production has gained significant traction as a promising alternative to fossil fuels, yet its widespread adoption raises questions regarding its environmental health and safety (EHS) risks. This review presents an overview of the current state of research in assessing these risks associated with solar energy production. Firstly, it examines the environmental impacts of solar energy, including the life cycle assessment of photovoltaic (PV) panels and solar thermal systems. Key considerations include the energy and resources required for manufacturing, transportation, installation, operation, and end-of-life disposal or recycling of solar panels. Furthermore, the potential for land use change, habitat disruption, and biodiversity loss due to large-scale solar installations is addressed. Secondly, the review discusses the safety risks associated with solar energy production, focusing on occupational health and safety hazards for workers involved in manufacturing, installation, maintenance, and decommissioning of solar energy systems. It examines exposure to hazardous materials such as lead, cadmium, and silicon during the manufacturing process, as well as the risks of falls, electrical hazards, and other workplace accidents during installation and maintenance activities. Moreover, the review highlights emerging technologies and best practices aimed at mitigating EHS risks in solar energy production. These include advancements in PV panel recycling technologies, improvements in manufacturing processes to reduce environmental impacts, and enhanced safety protocols and training for workers in the solar energy industry. While solar energy offers numerous environmental and economic benefits as a renewable energy source, it is essential to comprehensively assess and manage its EHS risks throughout the life cycle of solar energy systems. This review underscores the importance of ongoing research, innovation, and regulatory oversight to ensure the sustainable and safe deployment of solar energy technologies in the transition towards a low-carbon future.

Numerical simulation and experimental verification of solar PVT coupled PEM electrolyzer system for hydrogen production

Hydrogen production by electrolysis of water is the key to the future of hydrogen fuel production. This study proposes a hydrogen production system based on the thermoelectric demand for proton exchange membrane electrolyzers (PEMEs) and the characteristics of the thermoelectric output of photovoltaic (PV) thermal (PVT) systems. The proposed system combines PVT and PEME to realize thermoelectric hydrogen–oxygen multiproduction and establishes and validates the thermoelectric coupled numerical model used for the prediction of the operating characteristics of the PVT-PEME system. Furthermore, it investigates and compares the irradiation intensity, ambient temperature, and inlet flow rate of the PVT-PEME and PV-PEME systems, and estimates the operating characteristics of the PVT-PEME system in different climates. The results show that the electrolyzer energy efficiency tends to increase and then decrease with increasing irradiation intensity; the PVT-PEME efficiency increases with increasing ambient temperature; and the PV-PEME efficiency decreases with increasing ambient temperature. Moreover, the efficiency of the electrolyzer decreases with an increase in the inlet flow rate, but the PVT-PEME efficiency increases. The high temperature inhibits the performance of PV modules, which is promoted in PEME after heat exchange in the PVT system, improving the operating efficiency. In addition, an evaluation of the actual operating characteristics of the PVT-PEME hydrogen production system in different climates indicates that the system operated for shorter and less efficient times when operating at cold and low irradiation intensities.

A comprehensive investigation of porous media’s effects on the performance of photovoltaic thermal systems

Porous media in thermal collectors have been found to enhance the performance of photovoltaic thermal systems. However, there is a lack of comprehensive research on the benefits of using porous media in this context. This paper represents the first comprehensive study comparing various types of porous materials and their effects on system performance. The study employs a three-dimensional simulation to analyze the influence of factors such as material type, porosity, permeability, and thermal conductivity on module efficiency in top, middle, and fully filled configurations. In particular, it has been observed that each material has an optimum porosity, and there is little difference among metal foams, ceramic foams, and ordinary materials, such as aluminum and copper screens. Among the different configurations, the middle configuration had the lowest thermal efficiency improvement (∼17 %), the top configuration increased efficiency by ∼7 %, and the full porous configuration had the highest thermal efficiency improvement, 32 %. Materials with very low conductivity, such as wood, perform better in the middle than in the top configuration. Graphite, despite its high thermal conductivity, has low permeability, which leads to lower thermal efficiency compared to that of most other materials in the top configuration. In the full configuration and particularly in the middle configuration, graphite shows the smallest thermal efficiency improvement due to its significant longitudinal conduction heat transfer. Therefore, in these configurations, graphite is not recommended for use as a porous medium. Regarding added mass, metal foam materials add the most mass to the system, followed by ceramic foam materials, which present considerably lower figures. In all cases, the pump power consumption growth is negligible compared to the photovoltaic power output. In all materials and configurations, there was a small improvement in electrical efficiency, reaching 1.25 % in the full porous configuration. From a holistic perspective, this study showed that porous media can improve the overall equivalent power by up to 9.8 %, compared to a smooth channel.

Enhancing the performance of a photovoltaic thermal system with phase change materials: Predictive modelling and evaluation using neural networks

The study aims to develop a Photovoltaic thermal which generates both electrical and thermal energy as well as addresses the electrical power drop as temperature rises. For PV system, absorber tubes with rectangular spiral design were glued to the backside of a multi-crystalline PV panel for transferring the heat from the PV panel. For phase change material (PCM) integrated PV/T, a novel biochar-based PCM was also developed using biochar procured from water hyacinth and pure PCM(OM35) which was inserted in the gap in between the PV and back cover. The average value of electrical power output, electrical efficiency and thermal efficiency for PCM integrated PV/T 65.93 W, 12.54% and 61%, respectively, whereas the average value of electrical power output and electrical efficiency for the PV system is 54.513 W and 11.15%, respectively. The data obtained from field tests were used to develop a neural network model using Multilayer Perceptron for forecasting the performance of the same photovoltaic system. The proposed model accurately forecast the systems output performance as evident from the coefficient of determination (R) and mean error (MSE) values. During the training phase, the predictive model obtains an exceptional R-value of 0.9982 and a good MSE value of 1.1328.

Modeling and simulation of direct contact membrane distillation system integrated with a photovoltaic thermal for electricity and freshwater production

Energy drives the growth, transformation, and economic development of every nation. The vitality of human existence and progress hinges on the accessibility of both energy and water resources. As freshwater resources are diminishing, therefore, desalination needs have increased. In solar membrane distillation systems, the key challenge is maintaining the intake water temperature in the membrane distillation system with fluctuating solar radiation intensity which affects the distillate water quantity and quality. The objective of this study is to enhance and optimize a mathematical model for analyzing a cutting-edge solar-integrated PV/T-DCMD system. In this innovative integration, the direct contact membrane distillation intake water temperature is derived from the photovoltaic thermal output. The integration of direct contact membrane distillation with photovoltaic thermal systems represents a cost-effective and technologically advantageous concept. As the water temperature increases, there is a notable improvement in the evaporation efficiency of PV/T-DCMD systems, with an increase from 35.08% to 42.01%. Additionally, there is a reduction in specific thermal energy consumption, decreasing from 1,192 to 1,386 kWh/m3 as a consequence of the elevated feed water temperature.

Improving the overall performance of a hybrid photovoltaic system by reflectors and cooling with water jet

In the present research, the overall performance of the hybrid photovoltaic thermal PVT system used in the production of electric power and water heating has been evaluated. The PVT was coupled with reflectors to increase the energy production and cool it by water jet. The experimental tests were conducted in Iraq – Samarra located at the longitude (43 40 East) and the latitude (34 35 North). Several experiments were carried out through April 2021 in the outdoors. The highest overall instantaneous efficiency was 64%, and the highest percentage improvement in the PVT electrical performance with reflectors was 42.6% at a (0.0084 kg/s) load flow rate. The water temperature in the thermal storage tank increased by about (6°C/6 h) when the electric heater was turned on, while it decreased (6°C/6 h) without turning it on, and it consumed 18.7% of the total batteries energy, which makes it an ideal solution to compensate for the period of sun absence.

Energy based techno-economic and environmental feasibility study on PV/T and PV/T heat pump system with phase change material-a numerical comparative study.

A sustainable, affordable, and eco-friendly solution has been proposed to address water heating, electricity generation, space cooling, and photovoltaic (PV) cooling requirements in scorching climates. The photovoltaic thermal system (PV/T) and the direct expansion PV/T heat pump (PV/T DXHP) were numerically studied using MATLAB. A butterfly serpentine flow collector (BSFC) and phase change material (PCM) were assimilated in the PV system and MATLAB model was developed to evaluate the economic and enviroeconomic performance of the PV/T water system (PV/T-W), PV/T PCM water system (PV/T PCM-W), the PV/T DXHP system, and the PV/T PCM heat pump system (PV/T-PCM-DXHP). In this study, annual energy production, socioeconomic factors, enviro-economic indicators, and environmental characteristics are assessed and compared. Also, an economic, environmental, and enviro-economic analysis was conducted to assess the commercial viability of the suggested system. The PV/T PCM-DXHP demonstrated the highest electrical performance of 53.69%, which is comparatively higher than the other three configurations. The discounted levelized cost of energy (DLCOE) and payback period (DPP) of the PV/T PCM-DXHP were ₹2.87 per kW-h and 3-4years, respectively, resulting in a total savings of ₹67,7403 over its lifetime. Furthermore, installing this system mitigated 280.72 tonnes of CO2 emissions and saved the mitigation cost by ₹329,700 throughout its operational lifecycle.

Integrated photovoltaic-thermal system utilizing front surface water cooling technique: An experimental performance response

In the realm of photovoltaic-thermal (PVT) systems, optimizing operating temperatures for photovoltaic (PV) panels is a challenge. This study introduces a novel solution: a sprayed water PVT system that simultaneously harnesses energy and electricity. The aim is twofold: generate electricity through PV panels and produce hot water via a flat plate collector, using an innovative cooling mechanism. Water sprayed onto the PV panel's surface flows to a collector for storage. With varied flow rates, optimal panel efficiency occurs at a 45⁰ tilt angle, accompanied by lower collector outlet temperatures at higher flow rates. The collector achieves a peak thermal efficiency of 70.6 %, producing hot water at 84.6 °C. Notably, a significant PV panel efficiency enhancement, up to 16.78 %, especially at 1.56 L/min flow rate, is observed. The cooling technique consistently reduces panel temperatures from 45.08 °C to 34.12 °C. A self-cleaning spray mechanism improves efficiency by 2.53 %, resulting in an overall system efficiency of 83.3 %. This research offers an innovative approach to enhance energy generation and electricity in PVT systems, promising sustainable energy optimization.

Mathematical model to optimize solar spectrum allocation for a Stirling engine-based concentrated photovoltaic thermal system

Incorporating a Stirling engine into a concentrated photovoltaic thermal system (CPVT) with spectral beam splitting converts wasted photovoltaic panel energy into electricity, boosting efficiency. However, complex Stirling engine development slows system performance estimation, which explains the scarce studies on the Stirling engine-based CPVT spectrum allocation range. Furthermore, the literature shows inconsistent remarks on low or high-energy photon allocation to a thermal system and uncertainty of solar irradiance variation effect on spectrum allocation. A generic methodology is presented for determining optimal spectrum allocation for a Stirling engine-based CPVT system with a dichroic filter. The analysis in this work shows that considering non-absorption and thermalization losses improves performance by 13.2 % compared to solely accounting for non-absorption loss in beam splitting. Additionally, a shift of up to 40 nm in the optimal spectrum allocation range is observed with a daily spectral irradiance source compared to the AM1.5D source. The PV mathematical model is validated with an average error of 8.9 %, and the Stirling engine model with an error of 5.2 %. Through this study, future researchers can determine an optimal spectrum allocation range for Stirling engine-based CPVT that maximizes PV performance based on a specified location with the proposed generalized CPVT model.

Performance boost of an integrated photovoltaic-thermal and solar thermal collectors using minichannel heat sink: Energy, exergy, and environmental analysis

This case study investigates the enhancement of thermo-electric efficiency of an integrated photovoltaic-thermal and solar thermal collectors through the utilization of a minichannel heat sink. The integration of a photovoltaic-thermal collector and a solar thermal collector forms a cohesive system designed to minimize heat loss and streamline the external connection process. The energy, exergy, and environmental analysis of the integrated system are numerically investigated and compared by four solar systems including a photovoltaic module, solar thermal collector, photovoltaic-thermal collector, and simple channel-based integrated system. The results of energy analysis show that among the five investigated systems, the maximum electrical and thermal power is obtained using minichannel-based integrated systems, which are 0.8 % and 55.8 % higher than those of photovoltaic-thermal systems, respectively. By using minichannels instead of the simple channel, the electrical and thermal exergy of the integrated system increases by 0.80 % and 7.16 %, respectively. The greater effect of the solar radiation on the systems’ performance than other operating parameters is found from the results so the total power of the minichannel-based integrated systems increases by 245.39 W, by increasing the radiation rate from 700 W/m2 to 1100 W/m2. The annual CO2 mitigation of the integrated system, in term of energy, is 11.54 tCO2/annum, which is 81.5 % and 56.8 % more than photovoltaic module and solar thermal collector, respectively.

A novel concept of solar photovoltaic partial shading and thermal hybrid system for performance improvement

Large values from external causes, such as partial shade, can greatly influence output power of PV. The applications of partial shading are frequently utilized in simulation software. However, in this research work, partial shading and the integration of the photovoltaic Thermal (PV/T) Hybrid Solar Panel is implemented, and analysis is done to see how it affects the output power of solar panels under genuine climatic circumstances. Many research investigations have been conducted and researchers continue to look at PV/T systems to enhance their performance. The application is designed to provide information on solar panel output power under normal and partial shading situations. The maximum amount of power that solar panels can generate is 298.50 W. Under typical circumstances, partial shading in a solar panel can result in a maximum power value of 141.13 W, and this partial shading leads the power to increase.

Heat transfer and energy performance analysis of photovoltaic thermal system using functionalized carbon nanotubes enhanced phase change material

The photovoltaic thermal system (PVT) is an emerging technology that simultaneously generates both electrical and thermal energy from solar energy, aiming to improve solar energy utilization. However, significant technological issues with these systems obstruct their large-scale operation. The major drawback of the cooling fluid-based PVT systems lies in operation during sun-shine hours only. To address this issue, the present research endeavors a comparative study on with and without nano-enhanced phase change materials (NePCM) integrated PVT system. In this study, the performance evaluation of four configurations was analyzed with a flow rate varying from 0.4 to 0.8 litter per minute. From this, the experimental analysis was performed on two systems, including a photovoltaic and a PVT system. The simulation was performed using TRNSYS simulation on the phase change materials integrated photovoltaic thermal system, and NePCM integrated photovoltaic thermal system. The results indicates that increasing the flow rate by 2.2 times leads to a 4.9-fold increase in pressure drop, while the friction factor decreases with rising mass flow rate. Notably, the NePCM-integrated PVT system exhibited a substantial reduction in cell temperature and increased electrical power output at higher flow rates. At a flow rate of 0.4litter per minute, a significant heat gain was achieved with an impressive energy-saving efficiency of 75.67 %. Furthermore, the total efficiency of the PVT system, phase change materials integrated PVT system, and NePCM integrated PVT system were determined to be 81.9 %, 84.5 %, and 85.05 %, respectively. These findings underscore the potential of NePCM-integrated PVT systems for enhancing performance and expanding their practical application.

Classification and Parametric Analysis of Solar Hybrid PVT System: A Review

A Hybrid Photovoltaic Thermal (PVT) system is one of the most emerging and energy-efficient technologies in the area of solar energy engineering. This review paper provides a comprehensive review of hybrid PVT systems in the context of the history of PVT, general classification, and parameter analysis. Several cell technologies with spectrum analysis are discussed to understand the application’s ability and energy efficiency. Hybrid PVT concept, characteristics, and structure analysis is also discussed in this study. An extensive analysis on the classifications of hybrid PVT systems from the recent literature is also presented here. These literatures are identified based on several criteria. In order to provide a complete and energy-efficient technology, an innovative classification of the hybrid PVT system is proposed in this paper. This proposed classification is a combination and upgrade of various existing classifications mentioned in recent research studies. Parameters have a significant and unavoidable impact on the performance and efficiency of the hybrid PVT system. A brief analysis of different parameters and the optimization of the system is conducted after reviewing recent research articles. This analysis provides insights into the impact of parameter variations on the system. A novel parameter model comprising parametric and optimistic analyses is also presented in this paper. It provides a detailed parametric description that significantly affects the performance and efficiency of the hybrid PVT system. Finally, the assessment focuses on a critical analysis of the main challenges in adopting PVT technology and suggests ways to overcome these barriers.

Efficiency assessment of thermal radiation utilizing flow of advanced nanocomposites on riga plate

Utilizing nanostructured materials to optimize thermal processes for renewable energy is an important strategy that has been applied in numerous engineering disciplines for diverse interventions such as photovoltaic thermal systems. Ternary nanofluids have demonstrated potential for improving the cooling capabilities of this kind of system. The current research focuses on enhancing the thermal performance of convective flow of a water-based trihybrid nanofluid across a Riga plate incorporating carbon nanotubes in spherical, graphene in cylindrical and Al2O3 in platelet shapes. Several mechanisms like non-linear heat production, thermal radiation, velocity and thermal slip conditions have all been investigated regarding the flow describing equations. Due to the high complexity of the problem modeling and numerical methods, conventional techniques to the parametric work that incorporate various model factors can fail to derive accurate solutions. This study assesses the ability of soft computing techniques to determine the behavior of a problem with various connected parameters to resolve this issue. With help from numerical scheme Lobatto IIIa technique reference data, the artificial neural network is trained. Furthermore, a constructive technique using artificial neural networks (Levenberg–Marquardt) is used to quantitatively determine the rate of heat transmission on the surface of Riga plates. With the use of correlation, fitting analysis, regression, mean squared error, absolute error, and error histogram, the prediction performance of the proposed algorithms is examined. The Cfx and Nux reach convergence with mean squared errors close to 10−8 and 10−10 after 626 and 100 epochs. The investigation illustrates the benefits of using soft computing methods to accurately investigate the behavior of complex flow models. The most important discovery is that, in comparison to mono- and binary-hybrid nanofluids, ternary hybrid nanofluids have a greater thermal responsiveness.

Effects of climate variables and nanofluid-based cooling on the efficiency of a liquid spectrum filter-based concentrated photovoltaic thermal system

Effects of climate variables and nanofluid-based cooling on the efficiency of a liquid spectrum filter-based concentrated photovoltaic thermal system