Dynamic mechanical load tests on crystalline silicon modules.

The mechanical load test in the actual standard for photovoltaic module product qualification is simulating the combined wind and snow load by the means of a static load. Critical issues are the size, thickness and treatment of the module front glass, the stability of the framing and mounting scheme and the mechanical reliability of the solder joints. For crystalline silicon modules, micro cracks offer an additional risk. But operating conditions in the field and conditions during handling and transportation are not necessarily static. In this work we compare the effects of dynamic and static load tests and investigate their interaction with climatic stress tests. Different test combinations and sequences are evaluated with respect to electrical power losses and to possible changes that can be observed via electro-luminescence. The aim is to prove or improve the existing reliability tests towards a more complete simulation of real operating conditions and to broaden the portfolio of very fast reliability tests beyond the existing standards. Various test sequences are probed on identical commercial modules and the results are compared to the statistical test data from the laboratory’s database.