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Performance analysis of a hybrid photovoltaic/thermal and liquid desiccant system
摘要： Air dehumidification is widely applied in the civilian and industrial use, however, conventional vapor compression air-conditioning system consumes substantial power. Using renewable energy in the air handling process has potential to further reduce the power consumption, meanwhile ease the carbon emission. This paper proposes a novel liquid desiccant system integrated with a photovoltaic/thermal collector for deep dehumidification. The generated electric power drives a vapor compression chiller for cooling the desiccant solution for a two-stage dehumidification, and the releasing heat from the collector is used for the desiccant regeneration. Simulation studies indicated the proposed system has a superior power saving ability of 55.65% comparing with the conventional one, besides the equivalent power generation efficiency reaches 8.7%.
关键词： photovoltaic/thermal collector,two-stage dehumidification,Liquid desiccant dehumidification
更新于2025-09-16 10:30:52
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Performance, Limits, and Thermal Stress Analysis of High Concentrator Multijunction Solar Cell under Passive Cooling Conditions
摘要： Concentration of solar radiation onto the surface of triple-junction solar cells causes high cell temperature and system failure. Recently, several cooling methods were proposed for these systems. However, quantitative evaluation of the essential heat transfer coefficients to maintain stable operation of these systems at different meteorological and operating conditions is not found in the literature. Therefore, in this study, a comprehensive three-dimensional coupled thermal and structural model is proposed for the latest triple-junction AZUR SPACE solar cell. The model is used to investigate the performance of an HCPV system under different solar concentration ratios (CRs), ambient temperature, direct solar irradiance, wind speed, backside heat transfer coefficient, and copper-II substrate area ratios. In addition, a new structure of the solar cell is proposed by modifying the typical solar cell assembly by changing the area of the rear copper layer. The results indicate that by increasing the ambient temperature, CR and direct solar irradiance significantly increase the predicted cell temperature at the same backside heat transfer coefficient. In addition, increasing copper-II substrate area ratios significantly reduces the average cell temperature at the same backside heat transfer coefficient and CR. At the highest backside heat transfer coefficient, when the copper-II substrate area increased, the cell temperature decreased to a certain limit and subsequently remained constant. Critical values of the highest backside heat transfer coefficient were about 200, 600, 1000, and 1600 W/m2 K at CRs of 50, 500, 1000, and 1500 Suns, respectively. In addition, at the highest backside heat transfer coefficient of 1600 W/m2 K, the critical area ratio values were about 2, 3, 4, and 6 at CRs of 50, 500, 1000, and 1500 Suns, respectively.
关键词： Passive cooling,Concentrator photovoltaic,Thermal stress,Triple-junction solar cell
更新于2025-09-16 10:30:52
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Design and Performance of a 1.5 axis Sun tracking Concentrated Photovoltaic System
摘要： This paper reports the design and testing of a concentrated solar photovoltaic thermal (CSPVT) system. The system consists of the PV panel, its cooling system, the parabolic concentrator, and the sun tracking mechanism. Photo Voltaic Thermal (PVT) systems are already a promising technique for improving energy yields and efficiencies of PV panels. The current work adds a concentration effect to make further improvements, especially on yields. Unlike the case of other research which uses plane mirrors along the sides of PV panels, this work employs a single parabolic reflector of concentration ratio 1.3, integrated with the panel mounting. A cooling system is also integrated with the mounting, so that the specially designed sun tracking mechanism turns the entire assembly, keeping both panel and reflector facing the sun without affecting the coolant flow in the adjoining pipes. This is one of the novelties of this work. We use vertical axis tracking but with seasonal adjustment of tilt. Hence the 1.5 axis in the title of this paper. Southern hemisphere spring tests in Cape Town showed a 60.2% electric power gain when compared with yields from an identical fixed panel. We also develop and test a MATLAB program using actual weather data for the experimentation period, and do a TRNSYS simulation using the software’s embedded TMY (typical meteorological year) weather data for the period. We find MATLAB results to be closer to experimental ones, while TRNSYS ones are not far out on totals. We conclude that CSPVT has much potential to increase both yields and efficiencies. In addition, we suggest that TRNSYS simulation would probably be most useful in cases where actual weather data is not available.
关键词： CSPVT,efficiency,concentration,solar tracking,photovoltaic thermal
更新于2025-09-16 10:30:52
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Study of hybrid photovoltaic thermal systems
摘要： Sun is the primary source of renewable energy. It is abundant, inexhaustible and clean. It plays a very important role in the present energy crisis. Solar energy can be harnessed by hybrid photovoltaic thermal system to generate power and heat. These devices generate thermal and electrical energy simultaneously. Hybrid photovoltaic thermal systems have high efficiency. There is ample scope in this area as much work remains to be done. The hybrid system has huge potential in India where the availability of solar energy is spread throughout the country. The paper focusses on the study of hybrid photovoltaic thermal systems.
关键词： Photovoltaic thermal,PVT performance,Hybrid solar
更新于2025-09-16 10:30:52
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Evaluation and Design Criteria of Photovoltaic Thermal (PV/T)
摘要： More interesting research in the field of photovoltaic thermal is being conducted widely due to shifting interest in supplying both electrical and thermal needs especially in areas that suffer from small installation space. Photovoltaic thermal (PV/T) offers to produce both electricity and thermal power from solar irradiance within the same area; therefore, saving up space & other costs directed to installation. Moreover, various techniques & types have been studied and implemented to improve PV/T’s performance and combined efficiency. The aim of this paper is to review the fundamentals of this technology, current works in the field and show innovative designs of PV/T to illuminate the way forward for the technology for globe-wide recognition. Nanofluid and nano-PCM based PV/T collector was found to produce the highest efficiency among other types in tropical climate conditions. The performance evaluation criteria for this system was presented and explained. It is recommended to amend the current design by simplifying it for better use in building integrated applications and for residential consumers.
关键词： Photovoltaic thermal,Combined efficiency,PV/T,Nanofluid,Nano-PCM,Renewable energy,Solar energy
更新于2025-09-16 10:30:52
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Experimental study on the performance of a solar photovoltaic/thermal system combined with phase change material
摘要： We present a comprehensive analysis of a solar photovoltaic/thermal system combined with phase change material, i.e., a PV/T-PCM system. A fatty acid was chosen as the PCM with a phase transition temperature of 37 °C. A solar collector filled with PCM, which contained rectangular metal fins to enhance heat transfer, was used to cool the PV. Four-day experimental measurements were carried out under real outdoor climatic conditions in Shanghai, China. During the experiment, we examined two different intermittent thermal regulation strategies using a water circulation loop in the PV/T-PCM system to improve the overall solar energy utilization efficiency, and detailed comparisons were performed. The results indicated that the use of PCM in the solar collector could significantly mitigate the temperature fluctuation of the PV panel and improve the photoelectric efficiency. Due to the low thermal conductivity of fatty acid, the temperature stratification in the solar collector was still significant even with the addition of metal copper fins. The thermal regulation strategy of setting the temperature at 45 °C gave better performance and the overall efficiencies of Case 1 and Case 3 could reach approximately 91%. The overall efficiency of Case 3 and Case 4 was approximately 85% with the thermal regulation strategy of setting the temperature at 50 °C. More heat could be removed from the PCM in the solar collector using the relatively low temperature setting of the thermal regulation strategy. It was concluded that the overall energy utilization ratio of the PV/T-PCM system can be improved through a reasonable thermal regulation strategy; however, further work on the economics analysis of the system is still needed.
关键词： Phase change material,Photovoltaic/thermal system,Dual-axis tracker,Photoelectric efficiency,Photothermal efficiency
更新于2025-09-16 10:30:52
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A Detailed Optimisation of Solar Photovoltaic/Thermal Systems and its Application.
摘要： There have been various studies and experimental results analysing the operational behaviour of PVT, most of which has been done at steady state or quasi-state. Variable factors can be controlled to optimise the PVT output such as mass flow rate, irradiation falling on the PVT through tracking or incidence angles in a day and fixed factors that depend on the design of the chosen PVT system as well as location parameters such as ambient temperature, wind speed, Transport Fluid used, Difference in Structure, Packing Density, Nominal operating temperature, stagnation temperatures, Fill Factor, Thickness of each layer, Location and Latitude and Heat removal factor (harp or serpentine design). The aim of this research is to validate and predict the dynamic behaviour of PVT systems while accurately describing the factor responsible for the loss of efficiency at any point in time under various weather constraints. A commercial system was considered (Solar Angel PVT system) here and is simulated for an entire year. The system was modelled in MATLAB and solved in implicit RK-4 method. The research question finds out to establish the basis for a standard testing protocol for assessing PV-T performance throughout various differences. It also analyses the long-term dynamic performance of PV/T technology by providing evidential data analysis (solar irradiance, heat and electricity, ambient temperature, operational temperatures, flow rates and thermal storage capacity) while completing an assessment of PVT behaviour with respect to an equivalent PV under different weather conditions. The flow rates, heat removal factor and the location affect the thermal behaviour of the PV/T to a greater extent than nominal temperatures and stagnation temperatures.
关键词： Electric and Thermal Energy,Solar Photovoltaic thermal systems,Optimising,Solar Energy,Dynamic Modelling,Optimal operation of PVT,PVT systems with storage
更新于2025-09-12 10:27:22
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Performance optimization of a photovoltaic/thermal collector using microencapsulated phase change slurry
摘要： In a photovoltaic/thermal (PV/T) collector, a portion of absorbed solar energy is transformed into electrical energy, and the remaining part is transformed into thermal energy. Increasing waste heat collection and energy conversion rates are important to improve the performance of the PV/T collector. The utilization of microencapsulated phase change slurry (MPCS) in a PV/T collector to cool photovoltaic modules is an effective way, and electrical and thermal performances of the collector are improved. To investigate influences of operating parameters on performances of PV/T collector, numerical simulation is put into effect to analyze influences of the mass fraction of MPCS on the collector performance. The influences of MPCS mass flow rate and collector channel height on collector performances are also studied. When the flow rate is 0.005 kg/s and the channel height is 0.010 m, the PV/T collector obtains the best net efficiency with a MPCS mass concentration of 20 wt%. But electrical efficiency difference between 15 and 20 wt% is not obvious. With the growth in mass fraction, PV temperature drops more and more slowly because outlet fluid has not fully melt. Take PV/T collector performances into consideration, 15 wt% MPCS is a better choice to cool photovoltaic modules.
关键词： microencapsulated phase change slurry,photovoltaic/thermal collector,electrical and thermal performances,energy conversion efficiency
更新于2025-09-12 10:27:22
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Photovoltaic-thermal (PVT) technology: Review and case study
摘要： Nowadays, solar technology converts solar energy into electricity and heat separately. For electricity generation, the main obstacle is the fact that the photovoltaic cells produce less energy as the temperature increases. To overcome this, cooling techniques can be used to raise the efficiency of solar cells, in order to obtain greater power generation. The photovoltaic-thermal hybrid solar collector (or PVT) is an equipment that integrates a photovoltaic (PV) module, for the conversion of solar energy into electrical energy, and a module with high thermal conversion efficiency (T), which employs a thermal fluid. This optimization of solar conversion technology has the main objective of cooling the photovoltaic cells, for increased generation of electricity, while also resulting in useful thermal energy from the working fluid, therefore constituting a cogeneration equipment. The present work reviews the development and global panorama of PVT technology. Afterwards, a case study of a PVT system is presented, together with a theoretical and experimental study. A thermography analysis performed in this PVT system is also examined, which allows for a real-time study of its operating regimes in different conditions, mainly of its thermal behaviour, and for the diagnosis of hot spots that signal potential defects in the cells.
关键词： thermography analysis,Photovoltaic-thermal (PVT) technology,solar energy,hybrid solar collector
更新于2025-09-12 10:27:22
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Three-dimensional numerical investigation of a hybrid low concentrated photovoltaic/thermal system
摘要： Concentrated photovoltaic/thermal hybrid collectors have received ever-increasing attention due to the simultaneous output of electric and thermal energy. For further improvement of concentrated hybrid PV/T systems, a simulation method combining the multiphysics fields is necessary to accurately analyze the optical, thermal, and electric performance. Herein, a three-dimensional numerical study has been conducted on a low concentrated photovoltaic/thermal system utilizing a heat transfer fluid as the cooling medium and a compound parabolic concentrator as the mirror field. A finite volume (FV)-CFD code has been employed to simulate the entire model, where the optical modelling is validated theoretically with the Monte Carlo ray-tracing method. The influences of employing various heatsink designs (U-type and Z-type) and coolants (water, ethylene glycol, and therminol VP-1) are numerically investigated. The economic feasibility of the hybrid PV/T system is also assessed in comparison with the standalone PV-cell. Good compatibility with the empirical data was obtained when the appropriate modelling tunings were applied. It is also shown that, on a typical day, the total energy and exergy efficiencies of the system are up to 57.66% and 7.94%, respectively. The Z-type heatsink decreases the average PV-cell temperature than the U-type design, and also the output power is slightly enhanced.
关键词： Photovoltaic/thermal system,FV-DO radiation method,heat sink,energy and exergy analysis
更新于2025-09-12 10:27:22