Predicting the lifetime of HJT modules towards the outdoor real-world environment

Abstract

The high-performance silicon solar cells can be manufactured with the unique amorphous/crystalline heterojunction (HJT) structure. In the field applications of the photovoltaics, the durability of HJT modules has become an issue which gets a lot of attention. In this work, it was found that the ultraviolet-induced (UV-induced) degradation is largely caused by the decrease in short-circuit current, and UV cut-off polyolefin elastomers (POE) can effectively suppress the attenuation rate. Additionally, temperature and humidity also affect the module degradation rate, which was revealed through a series of damp-heat (DH) acceleration tests. From the analytical calculations of the data of UV and DH tests, Arrhenius activation energy of 0.43 eV was successfully derived. Accordingly, the Peck model was applied, which indicates that the lifetime of HJT modules can be predicted in the case of the specific climate parameters, such as temperature, humidity and UV irradiation. Based on this model, lifetime of HJT modules is around 22 years due to its stronger annual UV irradiation of over 72 kWh/m2 and over 80 % relative humidity (RH) in Hainan. By contrast, fortunately, lifetime of over 30 years is predicted at the lower UV irradiation of 48 kWh/m2 in Daqing and lower humidity of less than 55%RH in Ningxia, which are the typical photovoltaic climate zones of China.