Forecasting Environmental Degradation Power Loss in Solar Panels with a Predictive Crack Opening Test

Manufacturing, shipping & handling, installation, and in-field loading of photovoltaic solar panels are common contributors to the creation of cracks within the cells of a panel. Many cracks initially cause little or no power loss in the panel, but such tightly closed cracks may open over time due to environmental forces, and cause significant power loss and even failure of the module. We developed a method, using the LoadSpot tool, to apply a mechanical load to a panel to temporarily open pre-existing cracks while also allowing for electroluminescence (EL) imaging and flash IV testing. The change in the IV and EL measurements upon loading provides a quantifiable metric that can be used to evaluate reliability and durability. Such Predictive Crack Opening (PCO) tests have value in assessing preexisting damage as well as in the correlation with the degradation due to cracked cells opening upon environmental chamber and cyclic loading. We performed finite element modeling and simulation to illustrate the stresses applied at different load and mounting conditions. We demonstrate a wide range of mechanical loading and stress testing with accompanying EL and IV measurements which not only show the narrative of damage and power loss through static mechanical load, environmental chamber testing, and cyclic loading, but also suggests potential improvements which can be made to the order of chamber and cyclic load testing within the IEC 61215 standard. next.