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Challenges and opportunities for nanomaterials in spectral splitting for high-performance hybrid solar photovoltaic-thermal applications: A review
摘要： Hybrid photovoltaic-thermal (PV-T) collectors, which are capable of cogenerating useful thermal energy and electricity from the same aperture area, have a significantly higher overall efficiency and ability to displace emissions compared to independent, separate photovoltaic panels, solar thermal collectors or combinations thereof. Spectral splitting has emerged as a promising route towards next-generation high-performance PV-T collectors, and nanotechnology plays an important role in meeting the optical and thermal requirements of advanced spectral splitting PV-T collector designs. This paper presents a comprehensive review of spectral splitting technologies based on nanomaterials for PV-T applications. Emerging nanomaterials (nanofluids, nanofilms and nanowires) suitable for achieving spectral splitting based on reflection, diffraction, refraction and/or absorption approaches in PV-T collectors are presented, along with the associated challenges and opportunities of these design approaches. The requirements from such materials in terms of optical properties, thermal properties, stability and cost are discussed with the aim of guiding future research and innovation, and developing this technology towards practical application. Nanofluids and nanofilms are currently the most common nanomaterials used for spectral splitting, with significant progress made in recent years in the development of these materials. Nevertheless, there still remains a considerable gap between the optical properties of currently-available filters and the desired properties of ideal filters. Aiming to instruct and guide the future development of filter materials, a simple generalized method is further proposed in this paper to identify optimal filters and efficiency limits of spectral splitting PV-T systems for different scenarios. It is found that the optimal filter of a spectral splitting PV-T system is highly sensitive to the value of thermal energy relative to that of electricity, which therefore depends strongly on the application and location. The efficiency limit of spectral splitting PV-T collectors is significantly higher than that of standalone PV panels. The stability of nanomaterial filters remains a critical challenge for their long-term employment and also for high-temperature operation in practical applications.
关键词： Nanofilms,Spectral splitting,Nanomaterials,Thermal properties,Stability,Nanofluids,Optical properties,Cost,Nanowires,Hybrid photovoltaic-thermal (PV-T) collectors
更新于2025-09-23 15:21:01
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Evaluation of electrical efficiency of photovoltaic thermal solar collector
摘要： In this study, machine learning methods of artificial neural networks (ANNs), least squares support vector machines (LSSVM), and neuro-fuzzy are used for advancing prediction models for thermal performance of a photovoltaic-thermal solar collector (PV/T). In the proposed models, the inlet temperature, flow rate, heat, solar radiation, and the sun heat have been considered as the input variables. Data set has been extracted through experimental measurements from a novel solar collector system. Different analyses are performed to examine the credibility of the introduced models and evaluate their performances. The proposed LSSVM model outperformed the ANFIS and ANNs models. LSSVM model is reported suitable when the laboratory measurements are costly and time-consuming, or achieving such values requires sophisticated interpretations.
关键词： hybrid machine learning model,Renewable energy,photovoltaic-thermal (PV/T),least square support vector machine (LSSVM),adaptive neuro-fuzzy inference system (ANFIS),neural networks (NNs)
更新于2025-09-23 15:21:01
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A fully coupled numerical simulation of a hybrid concentrated photovoltaic/thermal system that employs a therminol VP-1 based nanofluid as a spectral beam filter
摘要： The realistic numerical modelling of multiphysics applications is an efficient way to precisely predict the operation of concentrated solar systems. Although many multiphysics conjugating approaches have been proposed in the literature, it is difficult to adopt such methods into simulating complex concentrated solar technologies. Consequently, this study introduces a novel 2D:3D numerical optical, thermal and electric coupling approach for a hybrid compound parabolic concentrator photovoltaic/thermal (CPC-PV/T) collector using a nanofluid as a spectral beam filter. In this approach, the volumetric absorbed radiation in each component of the system obtained from the non-gray 2D model is patched into the 3D model as a volumetric heat source using sophisticated computational tools. The main features of the full coupling method (FCM) are extensively analyzed and compared with the other two coupling methods previously adopted. Further, the module performance has been investigated employing both the nanofluid and base-fluid spectrum filters (BF-filter) compared with a stand-alone concentrated PV cell. From findings, the FCM can be applied to reveal more realistic operation characteristics of the proposed system compared with the other approaches, since the FCM can take into account the non-uniformity of solar illumination and the direction of reflected solar beams upon the receiver, along with the variation in the optical characteristics of utilized materials over the solar irradiance. Additionally, suspending indium tin oxide (ITO) nanoparticles into the Therminol VP1 oil raises the absorption rate over the thermal-bands with 62.5% higher than the use of BF-filter, whilst the cell temperature and the transmitted irradiance within the PV-band are obviously declined.
关键词： Radiative heat transfer,Multiphysics coupling method,Nanofluid,Concentrated photovoltaic/thermal system,Spectral beam filter
更新于2025-09-23 15:21:01
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A multistate investigation of a solar dryer coupled with photovoltaic thermal collector and evacuated tube collector
摘要： In this study, an indirect solar dryer was designed and manufactured using a Photovoltaic Thermal (PV/T) collector and Evacuated Tube (ET) collector. The main objectives of this system were to supply the thermal load of the indirect solar dryer, to ?nd the best model for the drying process, to present a new model to predict the drying process of Tarkhineh (the drying material) and to perform its life-cycle cost analysis (LCCA). The manufactured system was tested under the weather conditions of Sanandaj city, Iran and was compared with open sun drying. When the auxiliary heater was not used, the new model 1 was the best model to describe the drying of Tarkhineh in the open sun mode and the new model 2 was the best model to describe the drying of Tarkhineh in the solar dryer designed and manufactured in this study. The new models 1 and 2 were found to be the best models for describing the drying process of Tarkhineh at set point temperatures 55 °C and 45 °C, supplied by the auxiliary heater, respectively. The payback period of the PV/T solar dryer and ET solar dryer, assuming 300 sunny days/year, were 2.3 and 2.5 years, respectively.
关键词： Evacuated tube collector,Photovoltaic thermal (PV/T) collector,Payback period,Tarkhineh,Models of drying,Solar dryer
更新于2025-09-23 15:21:01
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Design and analysis of a hybrid concentrated photovoltaic thermal system integrated with an organic Rankine cycle for hydrogen production
摘要： Solar is one of the most promising energy sources because of the abundance of solar radiation in certain parts of the world. One of the main limiting factors of using traditional photovoltaic cells is that they require a lot of space to generate a significant amount of power. The alternative method, the concentrated photovoltaic (CPV) module, does not utilize the infrared part of the spectrum; thus, the concentrated photovoltaic thermal (CPVT) module was developed. In this paper, the design of a CPVT system coupling with an organic Rankine cycle (ORC) is analyzed where the CPVT thermal receiver acts as a heat exchanger in ORC to generate additional electrical power. The generated power by hybrid CPVT–ORC system is converted to hydrogen by an electrolysis system to store power. The performance of hydrogen production system using an integrated CPVT–ORC power generation system is analytically evaluated, and the results of the modeling and analyses are presented, involving assessments of the influence of varying several design parameters on the rate of hydrogen production. The CPVT and ORC together produce up to 1152 W of electricity under 160 suns solar concentration. When all the electricity is supplied to an electrolyzer, 0.1587 kg of 99.99% pure hydrogen is produced and stored for future use in a fuel cell. The electrolyzer operates at up to 57% efficiency and has an average performance of 725.5 kWh kg?1. The results revealed that coupling ORC to the CPVT enables the system to improve the electrical power generation and consequently diurnal hydrogen production increases up to 30%.
关键词： Concentrated photovoltaic thermal (CPVT),Electrolyzer,Solar energy,Hydrogen,Organic Rankine cycle (ORC)
更新于2025-09-23 15:21:01
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Exergy and energy analysis of wavy tubes photovoltaic-thermal systems using microencapsulated PCM nano-slurry coolant fluid
摘要： To develop a more efficient water-cooled photovoltaic-thermal system, energy and exergy analysis of a photovoltaic-thermal system with wavy tubes are investigated numerically using different coolant fluids. A comparison between the straight tube and wavy tubes is conducted for various wavelengths and wave amplitudes. The geometrical parameters of the wavy tubes as well as the velocity of the coolant fluid are examined. Besides, the consequences of coolant fluid including water, Ag/water nanofluid, microencapsulated phase change material slurry, and also a new type of cooling fluid called microencapsulated phase change material nano-slurry are studied. The results show that the electrical, thermal, and exergy efficiencies of the photovoltaic-thermal module enhance by using the wavy tubes compared with the corresponding straight tubes. By declining wavelength in a constant wavelength/amplitude, the heat absorbed by the heat transfer fluid raises. For the best configuration, the primary and exergy efficiencies of the module increase by 6.06% and 4.25%, respectively, for the wavy tubes system compared with those for the straight unit. Furthermore, in both configurations, by increasing the inlet velocity, the overall performance of the photovoltaic-thermal module increases due to a higher heat transfer rate. The results also reveal that among different types of cooling fluids, the microencapsulated phase change material nano-slurry has higher performance in terms of both energy and exergy efficiencies due to having higher thermal conductivity and heat capacity. By employing the wavy tube and the novel proposed coolant fluid, the primary and exergy efficiencies increase in comparison with a typical photovoltaic-thermal module.
关键词： Energy,Microencapsulated phase change material slurry,Wavy tube,Nanofluid,Photovoltaic-thermal module,Exergy
更新于2025-09-23 15:21:01
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Experimental analysis of a photovoltaic/thermoelectric generator using cobalt oxide nanofluid and phase change material heat sink
摘要： Nowadays, photovoltaic panels have been known as effective devices to harness solar energy. These panels mainly convert the UV and visible areas of the solar spectrum into electricity and the rest of the energy is dissipated. One of the favorable methods to take advantage of such dissipated heat is to combine thermoelectric generators (TEG) utilizing the IR area of the solar radiation with photovoltaic panels. Having the different and opposite impact on the efficiency of thermal photovoltaic cells (PV/T) and thermoelectric generators (TEG), the system operating temperature appears as a critical parameter in the productivity of a PV/T-TEG hybrid unit. In the present study, a novel heat sink for a PV/T-TEG hybrid system is introduced. The effectiveness of simultaneous usage of the Co3O4/water nanofluid and the improved phase change material (paraffin wax/Alumina powder) as a cooling method on the performance of the PV/T-TEG is examined throughout an experimental study. Then, the overall electrical, thermal and exergy efficiency of such a system is compared to the units with divers working fluids including water and 0.25%, 0.5%, and 1% nanofluid and the unit consisting of 1% nanofluid with non-enhanced PCM cooling method. The results reveal that using 1% nanofluid with enhanced PCM, as a cooling method, would improve the overall electrical efficiency by 12.28% compared to water cooling technique. Also, an increase of 11.6% in the exergy efficiency of the PV/T-TEG is observed in comparison with PV/T-TEG with the water cooling method. Hence, it could be concluded that the combination of this unit could contribute to harnessing solar energy more efficiently, compared to solo photovoltaic panels.
关键词： Photovoltaic thermal,Solar energy,Nanofluid,Thermoelectric generator,Phase change material
更新于2025-09-23 15:21:01
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Effects of pump power on performance analysis of photovoltaic thermal system using CNT nanofluid
摘要： In this study, a numerical simulation has been accomplished to investigate the performance of a photovoltaic thermal system (PVT) with respect to the energy consumption of fluid circulating. Three dimensional numerical models of the PVT system were conducted in ANSYS Fluent software using water-CNT nanofluid as working fluid. Three configurations of heat collectors were modeled to select the more efficient design for collecting the heat of the PV module. By applying the duct channel heat collector, the effects of CNT concentration and nanofluid flow rate on the electrical and thermal efficiency of PVT system were studied. With flow rate of 50 L/h of 0.1 v/v% CNT-nanofluid, the electrical efficiency of PVT system increased 11% in comparison to PV system at ambient temperature of 40 °C. According to the inconsistency of thermophysical properties of nanofluid, a sensitivity analysis was conducted to indicate the impact intensity of nanofluid thermal conductivity. It indicated that the application of a 15 W pump in PVT system decreased the electrical efficiency from around 13.9% to 12.9%. A coefficient of cooling efficiency (CCE) is introduced to compare the extra gain electrical energy with the energy consumption of the pumping system. By increasing the thermal conductivity of nanofluid, the CCE increased from 0.985 for 25 W pump to 1.015 for 20 W pump. Two practical methods were suggested and investigated with transient simulation to decrease the energy consumption of the pumping process up to 50%.
关键词： Pump power,CFD,Nanofluid,Efficiency,Photovoltaic/thermal
更新于2025-09-23 15:21:01
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Improving Thermal and Electrical Efficiency in Photovoltaic Thermal Systems for Sustainable Cooling System Integration
摘要： Research into photovoltaic thermal systems is important in solar technologies as photovoltaic thermal systems are designed to produce both electrical and thermal energy, this can lead to improved performance of the overall system. The performance of photovoltaic thermal systems is based on several factors that include photovoltaic thermal materials, design, ambient temperature, inlet and outlet fluid temperature and photovoltaic cell temperature. The aim of this study is to investigate the effect of photovoltaic thermal outlet water temperatures and solar cell temperature on both electrical and thermal efficiency for different range of inlet water temperature. To achieve this, a mathematical model of a photovoltaic thermal system was developed to calculate the anticipated system performance. The factors that affect the efficiency of photovoltaic thermal collectors were discussed and the outlet fluid temperature from the photovoltaic thermal is investigated in order to reach the highest overall efficiency for the solar cooling system. An average thermal and electrical efficiency of 65% and 13.7%, respectively, was achieved and the photovoltaic thermal mathematical model was validated with experimental data from literature.
关键词： Solar collectors,Photovoltaic,Outlet temperature,Solar cooling,Photovoltaic thermal systems,Thermal efficiency,Electrical efficiency
更新于2025-09-23 15:19:57
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A numerical study on a photovoltaic thermal system integrated with a thermoelectric generator module
摘要： In this work, a three-dimensional numerical model is developed to investigate the performance of a photovoltaic thermal system integrated with a thermoelectric generator module (PVT/TE). Furthermore, the effects of various operating parameters such as solar radiation, coolant mass flow rate, and inlet and ambient temperatures on the performance of both the PVT and PVT/TE systems are investigated and compared. Based on the obtained results, the electrical efficiency of the PVT/TE system, when exposed to solar radiation of 600 and 1000 W/m2, is 6.23% and 10.41% higher than that of the PVT system, respectively. Besides, the electrical efficiency of the PVT and PVT/TE by increasing the inlet fluid temperature from 26 oC to 34 oC, reduces by 2.58% and 4.56%, respectively. Furthermore, by increasing the ambient temperature from 26 oC to 34 oC, the electrical efficiency of the PVT reduces by 1.43%, the electrical efficiency of the PVT/TE increases by 0.82%. Based on the simulation results, the electrical efficiency of the PVT/TE system is much higher than that of the PVT system, while the PVT system benefits from higher thermal efficiency in comparison to the PVT/TE system.
关键词： Numerical simulation,Electrical efficiency,Thermal efficiency,Thermoelectric generator module (TE),Photovoltaic thermal system (PVT)
更新于2025-09-23 15:19:57