DEVELOPMENT OF INHOMOGENEITIES IN MULTI-CRYSTALLINE SILICON PV MODULES OVER TWO YEARS OF REAL OPERATING CONDITIONS

摘要

We track the evolution of inhomogeneities in the 17 kW multi-crystalline silicon PV array between years 6 and 8 of operation. For the second inspection, we modified imaging setup (electroluminescence, UV fluorescence and visual) for in-situ measurements. The majority of inhomogeneities further developed during this period, however the performance ratio degradation was -0.55%/a which is normal. Disconnected areas developed in 7% of the modules, but their effect was small and we even noticed reconnection of some disconnected areas. Cracks developed in 41% of the modules, but the total crack length increased for only 6%. UV fluorescence images were helpful at determining their age. Contact finger interruptions change was present in every module and the total area affected by them increased for 34%. Unexpectedly, ordered dark dots also became visible or more pronounced in 12% of the modules and shading between them became significantly more visible in 13% of the modules. We also noticed some other inhomogeneity changes.