Evaluation of the impact of stagnation temperatures in different prototypes of low concentration PVT solar panelsShow others and affiliations
2015 (English)In: ISES Solar World Congress 2015, Conference Proceedings, 2015, p. 993-1004Conference paper, Published paper (Refereed)
Abstract [en]
Photovoltaic thermal (PVT) solar panels produce both thermal and electric power from the some area. This paper concerns a PVT design where the series connected strings of cells are laminated using silicone to an aluminium receiver where the heat transfer fluid flows. An evaluation of the impact of reaching high temperatures in the cell structural integrity and performance is presented. Eight small test receivers were made in which the following properties were varied: Size of the PV cells, type of silicone used to encapsulate the PV cells, existence of a strain relief between the cells, size of the gap between cells and type of cell soldering (line or point soldering). These test receivers were placed in an oven for one hour, under eight different monitored temperatures. The temperature of the last round was set at 220°C which well exceeds the highest temperature the panel design can reach. Before and after each round in the oven, the following tests were conducted to the receivers: Electroluminescence (EL) test, IV-curve, diode function, and visual inspection. The test results showed that the receivers made with the transparent silicone and strain relief between cells experienced less micro-cracks and lower degradation in maximum power. No prototype test receiver lost more than 30% of its initial power, despite the large cell breakage shown in some receivers. Prototype receivers with transparent (softer) silicone showed much far less cracks and power decrease when compared to red (harder) silicone receivers. As expected, larger cells are more prone to develop micro-cracks after exposure to thermal stress. Additionally, existing micro-cracks tend to grow in size into larger micro-cracks relatively fast with thermal stress. The EL imaging taken during our experiment leads us to observe that it seems far easier for existing cracks to expand than for new cracks to appear.
Place, publisher, year, edition, pages
2015. p. 993-1004
Keywords [en]
Concentration, Electroluminescence test, IV-curve, PVT, Stagnation temperature, Concentration (process), Cracks, Cytology, Electroluminescence, Flow of fluids, Heat transfer, Ovens, Photovoltaic cells, Silicones, Solar cell arrays, Solar concentrators, Solar energy, Solar power generation, Soldering, Testing, Thermal stress, High temperature, Highest temperature, I - V curve, Low concentrations, Photovoltaic thermals, Series-connected, Visual inspection, Cells
National Category
Energy Systems
Identifiers
URN: urn:nbn:se:hig:diva-25746DOI: 10.18086/swc.2015.10.14ISI: 000437201200107Scopus ID: 2-s2.0-85017036384ISBN: 9783981465952 (print)OAI: oai:DiVA.org:hig-25746DiVA, id: diva2:1163361
Conference
International Solar Energy Society, ISES Solar World Congress 2015, SWC 2015, 8-12 November 2, EXCODaegu, South Korea
2017-12-062017-12-062021-06-16Bibliographically approved