In an effort to further improve testing standards for PV modules, Fraunhofer Institute for Solar Energy Studies and Fraunhofer Center for Sustainable Energy Systems have launched of the PV Module Durability Initiative (PVDI), which they say will offer a more robust testing protocol for a wide range of modules, exceeding the demands of IEC standard module certification.

The Fraunhofer collaborators claim the PVDI will be the first widely available program to generate extensive, quantitative reliability data for modules, relevant for their expected lifetime under different kinds of stress. The tests do not simply use pass/fail criteria but generate quantitative scores enabling the credible ranking of modules based on their likelihood to perform reliably.

The key differentiating features of the PVDI include extended accelerated testing, UV, damp heat with positive and negative voltage bias as well as dynamic mechanical stresses. Also included are typical stresses such as temperature cycling, humidity-freeze, and damp-heat, which have been extended in order to come closer to the actual lifetime stress of a module.

Testing according to the PVDI 2012 Test Protocol will start in October 2011. Several modules from leading PV module manufacturers will be part of the first round of testing.

Initial data will be published in the second quarter of 2012, together with the Test Protocol outline. The publication will include data from all modules tested, and rank the modules in several degradation indicators. Program participants will have access to a detailed level of data and findings.

The initiative also includes an R&D component and outdoor exposure testing which aims to constantly improve the tests and to offer better models for module lifetime predictions.

Fraunhofer ISE in Freiburg, Germany, and Fraunhofer CSE in Cambridge, MA and its new testing lab in Albuquerque, NM, will jointly operate the PVDI.

"Our new initiative will give investors a tool to obtain a quantitative, third-party, independent assessment on the long-term durability of PV modules," said Harry Wirth, director of Fraunhofer ISE's photovoltaic modules, systems, and reliability division.

"Performing testing and R&D in our labs in Germany and the U.S. will give us a great opportunity to serve global PV investors and manufacturers," explained Christian Hoepfner, director of technical operations at Fraunhofer CSE.

"In addition to providing manufacturers with our new PV module testing protocol, the PVDI research team will work closely with international R&D and standards communities to support development of an international testing standard for the assessment of PV module quality," he added.