4. 1 PV Module Design, Manufacture, Performance and Reliability
Summary / Abstract:
This work aims to obtain the current-voltage (I-V) parameters of individual solar cells in modules deployed in the field, without the need to contact the cells or the module. This is done by a novel method that is based on suns-photoluminescence (Suns-PL) measurements. From the obtained I-V curve, a large range of faults can be detected; furthermore, in many cases their cause can also be understood. A unique shading method is proposed that allows performing these measurements under normal daylight conditions. It is based on the principle that no significant external current can flow when a few cells in a series-connected sub-string of cells are fully shaded.