New developments in accelerated weathering tests for Back-contact modules

Back-contact solar modules made with crystalline silicon cells are, to-date, amongst the highest peak power density devices on the market and are predicted to retain this status in the coming years. One of the barriers to mainstream adoption of this technology was for some time the availability of reliable supply of conductive backsheet, back-contact solar cells and back-encapsulants, which has been addressed for some years now. Still the industry is continuously searching for better and cheaper bill-of-materials, however the introduction of these materials is very time-consuming as quite some accelerated ageing tests are needed to certify the solar modules, typically over a period of 5-6 months. In this study, three different methods have been investigated, showing a similar ageing profile achieved in a shorter timeframe. The first method is the use of a single-contact solar device, which is much more sensitive during ageing and thus gives a quicker indication of changes in material properties. The second method is the use of a thermal shock chamber instead of thermal cycling. The third method makes use of damp-heat testing at elevated temperatures.