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Accelerated degradation of solder joint interconnections in crystalline silicon photovoltaic (c-Si PV) modules drives the high failure rate of the system operating in elevated temperatures. The phenomenon challenges the thermo-mechanical reliability of the system for hot climatic operations. This study investigates the degradation of solder interconnections in c-Si PV modules for cell temperature rise from 25 °C STC in steps of 1 °C to 120 °C. The degradation is measured using accumulated creep strain energy density ( W acc ) . Generated W acc magnitudes are utilised to predict the fatigue life of the module for ambient temperatures ranging from European to hot climates. The ANSYS mechanical package coupled with the IEC 61,215 standard accelerated thermal cycle (ATC) profile is employed in the simulation. The Garofalo creep model is used to model the degradation response of solder while other module component materials are simulated with appropriate material models. Solder degradation is found to increase with every 1 °C cell temperature rise from the STC. Three distinct degradation rates in Pa/°C are observed. Region 1, 25 to 42 °C, is characterised by degradation rate increasing quadratically from 1.53 to 10.03 Pa/°C. The degradation rate in region 2 ,43 to 63 °C, is critical with highest constant magnitude of 12.06 Pa/°C. Region 3, 64 to 120 °C, demonstrates lowest degradation rate of logarithmic nature with magnitude 5.47 at the beginning of the region and 2.25 Pa/°C at the end of the region. The module fatigue life, L (in years) is found to decay according to the power function L = 721.48 T - 1.343 . The model predicts module life in London and hot climate to be 18.5 and 9 years, respectively. The findings inform on the degradation of c-Si PV module solder interconnections in different operating ambient temperatures and advise on its operational reliability for improved thermo-mechanical design for hot climatic operations. [ABSTRACT FROM AUTHOR]

• The crack growth energetics is applied to develop fatigue model for PRMMCs • To take the effect of microstructural parameters of PRMMCs, the MSL and EDD theory are considered. • Sensitivity analysis of present model provides significant effect of microstructural parameters on the FCG life of PRMMCs. The crack growth energetics is applied to develop fatigue failure prediction model for particle-reinforced metal matrix composites (PRMMCs). The fatigue crack growth (FCG) rates are evaluated by balancing the accumulated fatigue strain energy at the fatigue damage zone to the dissipated energy developed during FCG in the fatigue damage zone. Then, microstructural parameters are incorporated into the model using modified shear lag theory and enhanced dislocation density. The analytical closed form solutions accurately fitted the experimental data on FCG life predictions for different PRMMC. Finally, sensitivity analysis of present model provides significant effect of microstructural parameters on the FCG life. [ABSTRACT FROM AUTHOR]