Low-Cost Methodology for Series Resistance Spatial Characterization in PV Devices Through Electroluminescence Imaging
Abstract
This work proposes an integrated, low-cost methodology for the spatial characterization of series resistance (Rs) in photovoltaic (PV) devices through electroluminescence (EL) imaging using commercial digital cameras. The approach includes the development of a procedure for selecting optimal ISO and exposure time settings according to image quality requirements defined by international standards, as well as a systematic method for accurate focus determination during EL image acquisition. Established image preprocessing and calibration techniques were integrated with existing Rs estimation models, enabling both global and spatially resolved resistance mapping, where each pixel represents a local Rs value. The proposed methodology enhances the accessibility and accuracy of EL-based diagnostics, supporting performance analysis, degradation assessment, and fault detection in PV systems. Additionally, the method provides a reproducible workflow in accordance with international standards suitable for laboratory and field applications.
Keywords
Low-cost electroluminescence imaging, Electroluminescence image calibration, Series resistance in photovoltaic devices, Spatially resolved series resistance, Photovoltaic diagnostics