Lifetime Extension of Photovoltaic Modules by Influencing the Module Temperature Using Phase Change Material

The lifetime of photovoltaic (PV) modules is usually specified by manufactures to be approx. 25 years. Degradation and, in the end, failure are affected by several parameters. Over its lifetime, a PV-module is subjected to different environmental stresses. Here, thermal cycling due to weather variations (e.g. solar irradiance, wind, and ambient temperature) is a crucial impact factor. This contribution evaluates phase change material (PCM) in terms of achieving optimized temperature cycles to increase the lifetime of PV modules. To find an optimal design and composition for PCM-enhanced PV modules, a lifetime model is required. Here, the results of finite-element stress calculations are fed into simplified lifetime models to approximate the Wöhler curve. Using this approach, the positive effect on the module lifetime using PCM is shown and an outlook is given how to use it within a model-based design optimization process. For an exemplary and simplified use case, the calculated lifetime can be extended up to approx. 30% due to the PCM enhancement.