Title:	Quantitative Analysis of Electroluminescence Imaging of a PV Module with Different Mismatch Levels
Author(s):	J.D. Santos, A. Valverde, M.C. Alonso-García
Keywords:	Electroluminescence, Mismatch Losses, PV Module, Contactless Voltage Measurement
Topic:	Photovoltaic Modules and BoS Components
Subtopic:	PV Module Design, Manufacture, Performance and Reliability
Event:	36th European Photovoltaic Solar Energy Conference and Exhibition
Session:	4AV.2.6
Pages:	1127 - 1133
ISBN:	3-936338-60-4
Paper DOI:	10.4229/EUPVSEC20192019-4AV.2.6
Price:	0,00 EUR
Document(s):	paper

Abstract/Summary:

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The mismatch loss in a photovoltaic (PV) module is linked to the variance between cell’s performances. This variance can progressively increase with time due to the non-uniform nature of the module aging. The main difficulty to carry out the study of the mismatch between encapsulated solar cells is the impossibility of accessing to their current-voltage (I-V) curves. This problem can be addressed by means of the quantitative analysis of the electroluminescence (EL) of the PV module at different levels of injection current. In this work, a PV module especially manufactured to adjust the mismatch level is studied by means of EL. Some solar cells of the standard module can be exchanged by defective devices with high series-resistance or low shunt-resistance. The variance between cell’s performances is analyzed for each module configuration at different irradiance levels. This variance is correlated to the standard deviation of the operation voltage of the solar cells in darkness conditions ([VCELL]). This [VCELL] is assessed from the contactless measurement of cell voltages using EL. The obtained results are compared with those obtained from direct voltage measurement. The reliability of the procedure is analyzed and the possible causes of observed deviations are discussed.