Photovoltaic Systems
H. Eshghi; M. Kahani; M. Zamen
Abstract
The cooling process of photovoltaic (PV) panel is one the main issue in in the field of solar systems. The temperature of solar cells increases when solar radiation and also ambient temperature increase. Increasing the cell temperature reduces the electrical output power of the panels as well as their ...
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The cooling process of photovoltaic (PV) panel is one the main issue in in the field of solar systems. The temperature of solar cells increases when solar radiation and also ambient temperature increase. Increasing the cell temperature reduces the electrical output power of the panels as well as their lifetime. To solve this problem, various methods have been provided for cooling the panels. One of these methods is the application of heat pipes. In this research, a PV panel equipped with thermosyphon heat pipe is introduced. The thermosyphon was connected to the back sheet of the panel to enhance the cooling effect of the PV system. Instead of using polyvinyl fluoride polymer, unlike conventional panels, an aluminum plate was used to connect the heat pipe to the back of the panel to have better cooling. In addition, to increase the heat transfer area between heat pipe and back surface of the panel, a special groove was drilled on the aluminum plate. Three different filling ratios (25, 45 and 65%) of distilled water as the working fluid were used in thermosyphon. The best performance of the systems was obtained at 45% of filling ratio, in which, the electrical power of the PV panel equipped with heat pipe was around 3.2% better than the conventional PV panel. In this case, 6.8 °C temperature difference was observed in the water tank connected to the condenser section of heat pipe which means that 54 kJ heat was transferred to the water in the tank.
F. Salek; M. Rahnama; H. Eshghi; M. Babaie; M. M. Naserian
Abstract
In this study, a solar driven alkaline electrolyzer producer of hydroxy gas is proposed which is integrated with photovoltaic panels with single-axis north-south solar tracking system. The main novelty of this work is providing transient analysis of integration of alkaline electrolyzer to the PV panels ...
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In this study, a solar driven alkaline electrolyzer producer of hydroxy gas is proposed which is integrated with photovoltaic panels with single-axis north-south solar tracking system. The main novelty of this work is providing transient analysis of integration of alkaline electrolyzer to the PV panels equipped with solar tracking system. Furthermore, the transient model of the alkaline electrolyzer is employed to calculate its operating temperature, hydroxy production rate and the other operational parameters at various hours of the day. The electrolyzer and PV panels with tracking system are modelled in EES software. It is assumed that the system is installed in Shahrood city, therefore, the geographical data this city is used for seasonal analysis. The effective area of electrolyzer electrodes and PV panels is also assumed to be fixed at 0.25m2 and 50m2, respectively, in this study. Based on the results, employment of solar tracking system resulted in significant increment of PV panels power absorption rate resulting in power increment up to 4.2kW in summer. On the other hand, the transient analysis of the proposed alkaline electrolyzer showed that the maximum operating temperature of which reaches 80oC at around 12 AM in the summer cause of achieving maximum electrical current peak in summer. Therefore, an efficient cooling system should be employed in summer for decrement of alkaline electrolyzer temperature. The proposed system is capable of producing 7.6m3/day, 10.4m3/day, 7.2m3/day and 4.1m3/day hydroxy gas in spring, summer, fall, and winter, consecutively.