Film types AAA 3554, APA 3552, TPA 3570 and FPA 3572 from the Austrian company Isovoltaic AG passed the comprehensive test procedures, which lasted several months, and now bear the TÜVdotCOM test mark of TÜV Rheinland.
In recent years, manufacturers of composite films have increasingly launched products for the photovoltaic industry onto the market, but there has never been an internationally recognised standard for testing reverse-side films. Over the last 18 months, therefore, an expert team of material testers, product testers and photovoltaic specialists at TÜV Rheinland have collated such test requirements, says Jörg Althaus, head of the Photovoltaic Modules Qualification division at TÜV Rheinland, because reverse-side laminates for modules must be subject to numerous quality requirements that can be derived from international standards. In particular, these include the safety qualification of modules as per IEC 61730 and the type tests as per IEC 61215 and IEC 61646 (for thin-layer modules).
An international team of experts is now developing a harmonised standard, and TÜV Rheinland is contributing to this work. The requirements of TÜV Rheinland regarding reverse-side films for PV modules include thermal loading tests as well as other mechanical and electrical tests. The standard for the safety qualification of PV modules requires a relative temperature index, whereby properties such as mechanical rigidity and electrical insulating capacity are extrapolated on an Arrhenius plot to determine the continuous working temperature.
These values were determined some time ago by TÜV Rheinland for cables now it is the turn of front- and reverse-side laminates for PV modules. The resistance of the films to fire is determined via a flame spread index as per ASTM E 162. The effects of UV radiation and weather are determined according to the specifications of ISO 4892-2 for the ageing of plastics in climatic tests lasting 1,500 hours.
Here, the films are repeatedly sprayed with water and then dried by a xenon lamp, after which their tear-resistance and insulating capacity are determined. A partial discharge test as per IEC 60664-1 is also performed. This value is decisive, among other things, for the maximum system voltage of a PV module.
With this new service, TÜV Rheinland is expanding its comprehensive testing programme for the entire solar industry. Today, around 80 percent of all manufacturers of photovoltaic modules worldwide have their products tested in the seven TÜV Rheinland laboratories around the world in order to obtain international market licences.
A total of 180 specialists are involved in testing modules and components, developing new test methods, collaborating on R&D projects for the use of solar energy and assisting customers worldwide with the construction of solar power plants. Contacts for editorial questions: Jörg Meyer zu Altenschildesche, TÜV Rheinland Press, joerg.meyer@de.tuv.com, phone +49 (0)221 8062255.
