Stabilization processes and air mass influences for outdoor exposure of thin film modules

Various types of modules were installed on a outdoor test facility. IV-curves of all these modules are measured every ten minutes. Measured irradiation, module temperature and air mass are used for analysis and comparison of the IV-curves. The influence of the respective air mass was higher than expected. Different correction procedures have been compared. Best results are achieved when the data are selected in a small range of air mass and module temperature and corrected to the same irradiation. Modules of the same types like the outdoor exposed modules were stored without irradiation for some years. Afterwards, they were exposed at the outdoor test site together with the other modules. Comparison of the module data of the same type allows the investigation of the stabilisation behaviour of the modules directly.