Inter-laboratory comparison of UV-light sources for accelerated durability testing of PV-modules

Accelerated testing of the durability of materials exposed to natural weathering requires testing of the UV stability, especially for polymeric materials. The type approval testing of PV-modules according to the standards IEC 61215 and IEC 61646 includes a so-called UV-preconditioning test with a total UV dose of 15 kWh/m2. Fraunhofer ISE performed an Inter-laboratory comparison of UV-light sources in accredited test labs and in test centres of major PV module manufacturers. One topic was the spectral measurement of the used UV sources. Another main issue was the comparison of the integral measurements by the sensors used for control of the tests. Errors up to 120% were found.