POST MORTEM ANALYSIS OF BIFACIAL PV MODULES BASED ON N-TYPE CRYSTALLINE-SI CELLS USING THREE DIFFERENT TYPES OF ENCAPSULANTS

摘要

The IEC 61215 standard for PV modules requires a damp heat (DH) test (1000 h at 85°C, 85% relative humidity). To have a better alignment with field observations extended and/or sequential testing protocols have been proposed, which involves for DH test a longer testing time under the same conditions. In this study small sized bifacial PV modules containing 1 or 4 n- and p-type x-Si cells have been subjected to extended DH testing up to 2500 h, resulting in encapsulant specific degradation. Several factors determining this degradation have been investigated by means of post mortem analyses of degraded samples. The precise composition of the cell metallization appears to play a key role. Besides that the nature of the encapsulant used has a significant influence as well, which can be related to release of acidic compounds and moisture permeability.