Influence of acceleration testing and anti-reflection coating on crystalline Si photovoltaic unencapsulated modules with polycarbonate base

A new concept of unencapsulated photovoltaic (PV) modules was developed to avoid several degradation phenomena caused by encapsulation materials, to facilitate recycling of PV modules. The reliability and durability of the new concept module were investigated through damp heat (DH) and thermal cycling (TC) tests. The maximum output power of the new concept module did not decrease significantly after 3000 h of DH testing and 1200 cycles of TC testing. Furthermore, no significant decrease was also observed in sequential testing of the total of 1800 h of DH testing and 600 cycles of TC testing. It was also found that UV absorbers prevent degradation of polycarbonate cover material used to enable to be lightweight and installed on curved surface and that MgF2 coating on cover material suppresses reflection loss of incident light. These experimental results indicate that unencapsulated PV modules are reliable enough for replacing conventional modules.