Fraunhofer ISE questions accuracy of standard UV testing

Fraunhofer ISE, a Germany-based research institute focused on solar energy systems, has recently studied UV degradation in TOPCon PV modules. AS per Fraunhofer ISE, standard UV lab tests tend to overstate degradation, as modules lose efficiency during dark storage but recover when exposed to sunlight. The institute said that performance measured immediately after UV exposure may not reflect actual field conditions. As per the findings, sunlight stabilization after UV testing is necessary to ensure accurate evaluation. Fraunhofer ISE reported that while some modules showed up to 5% power loss, others had minimal losses after stabilization. Field tests and returned module analysis confirmed that real-world degradation was consistently lower than simulated results. The study was presented at the SiliconPV conference.