Detecting Photovoltaic Module Failures in the Field During Daytime With Ultraviolet Fluorescence Module Inspection

Abstract

We present the potential of ultraviolet fluorescence imaging for the detection of function and safety failures of photovoltaic modules in the field. We apply this method to detect hotspots, mismatched cells, power-loss-inducing cracks, and we show how we use it to evaluate the crack history of a module. We present a device able to acquire fluorescence images in the field in the daytime without disconnecting the modules and with a throughput of more than 200 modules per hour for a single operator. Furthermore, we show how the technique allows for the discrimination of specific damages caused to the photovoltaic modules by sudden events such as hailstorms. We demonstrate that this method possesses an informative potential comparable to both thermography and electroluminescence together with less practical limitations.