By Jörg Althaus, Bussines Field Manager for Renewable Energy, TÜV Rheindland Immissionsschutz und Energiesystem GmbH
Photovoltaic modules and components, due to the nature of their employment, must be designed to withstand the most diverse of environments. The large spectrum of climatic conditions and mechanical stresses that these components must weather merit the application of some standards by which they can be tested for durability, reliability and safety. TÜV Rheinland operates several ISO 17025-accredited laboratories worldwide for type approval testing of flat plate as well as concentrating PV modules, PV components and solar thermal systems. Test data, collected over the past 20 years, shows that there is still a rather high failure rate when it comes to testing of PV modules, and also that there are different failure mechanisms for crystalline and thin-film PV modules. This paper presents data from these tests and draws some conclusions regarding the need for future standards development.