Experimental evaluation of photovoltaic thermal (PVT) system using a modular heat collector with flat back shape fins, pipe, nanofluids and phase change material

• Published in: Solar energy materials and solar cells Vol. 280; p. 113294
• Main Authors: Madadi, Mohammadreza, Abbasian Arani, Ali Akbar
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.01.2025
• ISSN: 0927-0248
• DOI: 10.1016/j.solmat.2024.113294

In recent years, the study of decreasing photovoltaic (PV) units cell temperature increase caused by solar excess energy, which is converted into heat rather than electrical energy, resulting in voltage output reduction and thereby lowering overall efficiency, has been the trending subject of much researches. In this study, a novel heat collector, which is an assembly of a series of flat heat sinks and serpentine copper tubes in an enclosed sealed container filled with paraffin wax is proposed. This assembly as an individual set is clamped and attached by screws to the rear side of the photovoltaic panel. The proposed system was experimentally investigated outdoors by utilizing SiC/water and Graphene/water nanofluids and water as cooling mediums with volume fractions 0.2 % and 0.4 % at 0.5LPM and 1LPM flow rates and this system was compared with a photovoltaic panel with no cooling. The achieved results showed that both nanofluids caused temperature drop compared to using water as coolant and the system with no cooling. Also, experimental results showed that the Graphene nanofluid caused more temperature reduction and accordingly resulted in higher power and efficiencies. Moreover, increasing volume concentration and flow rate of the working fluid led to have better performance in all the tests. Also, increasing volume concentration of nanofluid and flow rate caused to have more temperature reduction and as a result, more enhancement in electrical and thermal efficiencies. Photovoltaic thermal (PVT); Heat collector; Flat back shape fins, Fins, Nanofluids; Phase Change Material (PCM). Schematic diagram of the hybrid PVT system equipped with tube and finned on back side of collector Overall efficiency for PVT modules at 1 LPM. [Display omitted] •Highest temperature reduction in peak hours was about 11.7 and 8 °C using nanofluid.•Maximum electrical efficiency was about 10 % for Graphene/Water-PVT with 0.4 vol%.•Average thermal efficiency was 18.8%–51.9 % by varying flow rate from 0.5 to 1 LPM.•Average overall energy efficiency was improved by 28.2%–62 % using nanofluid.•Average total exergy efficiency was between 10.2 % and 11.3 %.