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Performance enhancement of photovoltaic panels using two types of nanofluids
摘要： One of the main problems that limit the extensive use of photovoltaic (PV) systems is the increase in the temperature of PV panels. Overheating of a PV module decreases the performance of the output power by 0.4% to 0.5% per 1°C over its rated temperature that in most cases is 25°C. An effective way of improving electrical performance (power output and efficiency) and reducing the rate of thermal degradation of a PV module is to reduce the operating temperature of the PV surface by a cooling medium. To achieve this, nanofluids can be considered as a potentially effective solution for cooling. In this study, two types of nanofluids, namely Al2O3 and TiO2 water‐based mixture of different volume flow rates and concentrations (0.01%, 0.05%, and 0.1%) by weight, were used. Also, three PV panels were cooled simultaneously using nanofluids, water, and natural air, respectively. Results showed that nanofluids for cooling enhanced heat transfer rate much better than water and natural air. Best results were achieved for TiO2 nanofluids at the considered concentration (0.1 wt%). Nanofluid cooling of turbulent flows for such an application has not been investigated before. These results represent the first application of nanofluid cooling in the turbulent flow regimes and in outdoor conditions including real solar irradiation.
关键词： photovoltaic module,Nusselt number,Al2O3,TiO2 nanofluids,heat transfer,electrical performance
更新于2025-09-23 15:19:57
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Effects of substrate-controlled-orientation on the electrical performance of sputtered BaTiO <sub/>3</sub> thin films
摘要： In this work, the relationships between bottom electrode/substrate configuration, crystalline microstructure, and electrical performances of BaTiO3 (BTO) thin films were investigated. The films were fabricated via RF magnetron sputtering on (Sr0.5La0.5)CoO3 (LSCO) buffered (110)-, (111)-SrTiO3 (STO) and SrRuO3 (SRO) buffered (110)-, (111)-MgO (MGO) substrates. The x-ray diffractometer results show that the LSCO/STO substrate resulted in films with high-quality epitaxial orientation, whereas the SRO/MGO substrate resulted in films having a strong (110) texture. The electrode/substrate configurations were designed to control the crystalline microstructure, which in turn affects the electrical performances of the films. The electrical performances were studied by employing a metal/ferroelectric/metal model. The J-V characteristics show obvious asymmetry with bias, which is mainly due to the varying transport state of oxygen vacancies. BTO films grown on LSCO/STO substrates exhibit large dielectric frequency dispersion, while those grown on SRO/MGO substrates display a nearly frequency independent response. All electrical parameters of these films were strongly affected by the polarization-tilting angle and the preferred orientation degree. Epitaxial and textured (110)-oriented films show higher permittivity but lower loss tangent, free-carrier concentration, built-in voltage, and leakage current density as compared to the epitaxial (111)-oriented film.
关键词： dielectric properties,electrical performance,substrate-controlled-orientation,BaTiO3 thin films,RF magnetron sputtering
更新于2025-09-23 15:19:57
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Thermal and electrical performance evaluation of PV/T collectors in Southern India
摘要： Combination of Photovoltaic and solar thermal collectors is used for the simultaneous production of electricity and heat. The proposed research work evaluates the thermal performance of Photovoltaic/Thermal (PV/T) hybrid collectors for the hot and humid weather condition of North Tamilnadu, South India. It is done by providing the cooling arrangement under the collector using wooden duct with baffles. Various parameters influencing the performance of the collector such as solar irradiance, ambient, glazing and tedlar temperatures, air inlet and outlet temperatures at the duct, velocity and mass flow rate of air inside the duct are analysed. The thermal and electrical performances of the PV/T collectors are evaluated under natural and forced circulation of air through the thermal collector. The experimental results are presented in this paper.
关键词： thermal performance,cooling arrangement and wooden duct with baffles,PV/T collectors,electrical performance
更新于2025-09-19 17:15:36
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Thermal and electrical behavior of built-middle photovoltaic integrated Trombe wall: experimental and numerical study
摘要： This study proposed a new system with the photovoltaic (PV) panel installed in the middle of channel of the Trombe wall (TW) system, called as built-middle photovoltaic integrated Trombe wall (PVMTW), which can realize multiple functions of electricity generation, space heating and heat preservation. The experiment rig was built to study the temperature field of the PVMTW system in heating seasons, in Hefei. A mathematical model of the PVMTW system was developed and validated against experimental data. Using the validated model, the thermal performance of the PVMTW system was investigated by comparison with that of the classic Trombe wall. The results showed that in the daytime, the average thermal efficiency of the PVMTW system was 65.2% higher than that of the classic TW system. In terms of room air temperature and interior surface temperatures on the walls, the indoor thermal comfortable of the PVMTW system was almost the same as that of the classic TW system. The average predicted mean vote (PMV) for two rooms (room with the PVMTW system and room with the classic TW system) were 0.05 and -0.36, respectively. Additionally, the average electrical efficiency and average total efficiency achieved 0.120 and 0.585, respectively.
关键词： PMV index,PV Trombe wall,Electrical performance,Total efficiency,Thermal comfort
更新于2025-09-12 10:27:22