Worldwide Physics-Based Analysis of Solder Bond Failure in c-Si Modules for Lifetime Prediction

Lifetime prediction of the fielded c-Si solar modules due to location-specific weather conditions has been an important topic of photovoltaic research and the economic viability of solar energy. Data analytic techniques such as Performance Ratio method, Statistical Clear Sky model, and Suns-Vmp methods quantify the degradation from measured data of a solar farm, however, the non-linear time-dependence and correlated degradations make it difficult to use the empirical degradation rates for ultimate lifetime projection. In this paper, we propose a complementary physics-based model to predict the solder bond failure caused by mechanical stress associated with the daily or seasonal variations of the temperature. Given the worldwide weather information from NASA database, the proposed model predicts the location-specific output power degradation and the lifetime of a module due to solder bond failure. The model parameters are obtained by calibrating against qualification tests involving thermal cycling. This model will serve as a building block of a more comprehensive reliability model that can predict the lifetime of a module that experiences simultaneous and correlated degradation mechanisms involving yellowing, corrosion, and potential-induced degradations.