Speaker
Description
The rapid development of PV worldwide requires the reliable prediction of module lifetimes and appropriate reliability paradigms in order to guarantee the technical and economic feasibility of the technology. However, existing empirical methods for predicting the degradation of PV modules, based mostly on past performance, frequently neglect climate-related variations on a site-by-site basis and the complex interactions between physical and chemical phenomena that lead to degradation during operation. There is thus an increasing necessity to abandon empirical methods in favor of physics-based modeling.
In this study, a multi-physics framework is proposed, which creates a direct connection between environmental stresses, material aging, and electrical degradation in field-aged polycrystalline silicon PV modules. This framework combines moisture diffusion with Shockley–Read–Hall recombination model and bandgap narrowing dynamics to simulate the defect density and carrier lifetime changes. Moreover, encapsulant photo-oxidation dynamics are combined with optical transmission loss and metal corrosion dynamics to determine the time-dependent changes in short-circuit current, open-circuit voltage, and fill factor. The coupled effects are then represented in a single power law for computational convenience of predicting reliability. Using mechanism-based prediction instead of empirical extrapolation, this framework can be helpful in determining failure modes and optimizing PV materials according to specific climates.
| Topic Area | Fatigue, Corrosion and Structural Integrity of Engineering Structures and Mechanical Systems |
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