Researchers and technicians at the Berlin, Germany-based Photovoltaik-Institut Berlin (PI Berlin) will unveil a new high-volume, automated electroluminescence measurement (EL) technique at next weeks Intersolar Europe conference that the institute claims can dramatically reduce testing and analysis time.
The new automated EL process allows examination of a module without dismantling it, making it possible to test up to 1,000 modules in a single night, the researchers claim. PI Berlin’s new technique allows for several modules to be tested at once without having to remove them from the array.
The test images produced by the EL process are then analyzed by specially developed software, providing accurate imagery and information to system owners on the look out for damaged or faulty modules that may need replacing.
A recent case study using the EL technology was carried out at a power plant in Italy, with PI Berlin engineers able to test more than 12,000 installed polycrystalline modules in less than three weeks. Their findings revealed that more than 80% of installed modules were defective, with the EL testing picking up badly fractured cells in the center of many modules, resulting in considerably reduced yields.
"Our analysis shows that PV modules are frequently damaged during transportation," said PI Berlins head of module technology research Juliane Berghold. "This is indicated, for example, by prominent cell fractures that occur fairly consistently in the middle of the majority of modules in a plant. In such cases, the damage we see can be attributed to a combination of the transportation method and relatively sensitive modules."
PI Berlin will showcase its EL test methods at the forthcoming Intersolar Europe exhibition, which opens on Wednesday (June 10) next week. The PI Berlin team will explain how high-resolution EL images of several modules are created, analyzed and automatically evaluated by their software, which has been created after years error analysis and development.
"This expertise helps us to evaluate these results very quickly and recommend specific courses of action for solving problems in the plant," added Berghold.
Deutsche Bank has already commissioned the testing system to help it evaluate its own power plant assessments, PI Berlin confirmed.