This is a measuring method with which you can see into the cells of a solar module. It can be seen defects which affect the performance of a solar module..

Measuring procedure:
An external voltage is applied to the module. The tension results in a radiation of photons. The module is illuminated with radiation in the near infrared, invisible for the human eye. The radiation which is emitted by the module is stored by a photograph. 

Documentation of defects
The recognizable defects affect the module performance and the lifetime of the module.

The following is a compilation of recognizable abnormalities:

These abnormalities or deficiencies and defects described can be detected by a EL-Photograph in a short time. It is possible to draw conclusions about material and workmanship.