Assessment of leaching tests for evaluating potential environmental impacts of PV module field breakage

Test methods from standard waste characterization leaching tests used in the U.S., Germany, and Japan were evaluated to determine if they can be used to help evaluate potential environmental impacts from PV field breakage. To assess the representativeness of leaching test methods, PV module breakage types were evaluated from warranty return data. Field breakages mainly consist of various types of stress and impact fractures in which modules remain largely intact with a number of glass fractures or cracks. By breaking modules into cm-scale pieces and tumbling them in solvent, waste characterization leaching tests can be more conservative than PV field breakage conditions with regards to parameters such as sample size, solvent, and treatment method. An alternative test method was previously used in Japan in which modules with a predetermined number of cracks were subjected to simulated rainwater. This approach is more representative of field conditions as modules are more likely to experience cracks under field conditions then to break into pieces.