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Homogeneity Measuring Unit

Quality Checks for Solar Panels in Research and Industry

The efficiency of each and every industrially produced solar panel must be measured precisely before it leaves the factory. 


Large flashbulbs, so-called “flashers” are normally used for these measurements. The light spectrum of a flasher, which is only emitted for a few milliseconds, must be as similar as possible to solar radiation with respect to intensity and spectral distribution across the entire area of the panel.

Homogeneity, intensity and spectral distribution of the emitted light are therefore critical parameters when it comes to the reliable determination of panel efficiency. A homogeneity measurement system for quality-checking the flashers was developed at the Institute of Energy Research - Photovoltaics (IEF-5) of Forschungszentrum Jülich GmbH.

Eighty sensors for the simultaneous measurement of illumination intensity are arranged on an area that can be flexibly adapted to the requirements. The flash induces the information of the sensors to be recorded without time delay and in an absolutely synchronous manner. It is then buffered and sent to a computer for evaluation by a data processing system. The result can be shown in the form of a two-dimensional, spatially resolved and interpolated graphic representation by means of extensive evaluation (see image on the left). Thanks to the various measurement data, the flasher can be accurately calibrated.

Knowing these values is a prerequisite for determining the exact efficiency of the solar panel and is thus important for quality control in industrial panel manufacturing.