Quality assurance of photovoltaic modules
Solar energy is continuing to experience a meteoric rise. Materials testing plays a decisive role in optimizing efficiency and in the service life of the modules. Bosch Solar Energy AG opts for quality assurance based on testing technology by Zwick.
With an expected service life of 20 to 40 years, wafers, solar cells, modules, etc. are subject to stringent requirements because roof-mounted photovoltaic systems have to be able to withstand extreme weather conditions. Various testing methods are used to verify a wide range of materials and components. The connections between plastic coatings and carrier materials in the modules are frequently tested.
A Tedlar® film on the back of the glass plate protects the modules from external influences. The strength of these connections is tested with the 90 degree peel test. This involves gripping the Tedlar® film in screw grips and pulling it off the glass plate. Zwick offers a special tool for this. On the one hand, this test is performed to support the process of checking the machine parameter settings. On the other, the test is used both in the checking incoming goods and as part of a requalification test following expiry of minimum shelf lives. In order to meet the applicable standards, the Tedlar® film must withstand peel forces of up to 500 N.
Bosch Solar Energy uses a materials testing machine of the ProLine series for this test. This test solution enables the testing of segments with a maximum size of 400 x 400 millimeters. Furthermore, tools for different tests can be integrated into the machine at any time. Implementation and evaluations are performed by the intelligent testing software testXpert® II.
The modular system can be expanded for:
shear tests on “composite safety glass”, 180 degree peel-off tests on the contact rails of solar cells, double-ring compression tests on “single pane safety glass”, peel tests on contact boxes on the rear of solar modules, tensile tests on the strain relief devices of connector cables.
