Reliability of Electrically Conductive Adhesive Joints for PERC and HJT-Based Building-Integrated Photovoltaic Facade Elements

Integrating photovoltaic solutions directly into building facades presents a crucial strategy for achieving Europe's goal of climate neutrality by 2050. A widespread adoption of building-integrated photovoltaics (BIPV) can bolster energy security, diversify the energy mix, and create new green jobs. By seamlessly integrating renewable energy generation into our cities, BIPV becomes a cornerstone of a sustainable future for Europe and keeping aesthetic and functional benefits, such as providing shade, mitigating heat gain, and enhancing the overall building envelope performance. To achieve such goals, especially the building and construction sectors needs to be facilitated to adapt photovoltaic technologies into their production and value chains. With the results of the AluPV project, we will demonstrate how PV production processes and material combination can be adapted to realize PV-integrated aluminum facades as building-integrated photovoltaics elements. One main objective is to adapt the manufacturing process to handle redesigned photovoltaics modules, in terms of electrical adaptation due to other dimensional and architecture constraints and mechanical structures due to direct incorporation with Al-façade elements. Therefore, suitable material combinations and process parameters were studied, with particular attention to reducing mechanical stress and utilizing cost-effective standard PV production equipment. Within the paper, we demonstrate our findings to successfully use commercially available aluminum façade elements as backside encapsulation and solar cell string material layer. Standard industrial lamination equipment was demonstrated to be suitable for cost-efficient production and rapid implementation of the prototype into the production line. A material study will show an optimum of material types and layers for reliable façade modules. Test sequences according to IEC are performed and performance measurements as well as electroluminescence (EL) images were applied to quantify our findings. In summary, multiple challenges related to manufacturing and material selection were addressed, especially the differences in the thermal expansion of the materials. Modules with an aluminum back sheet show less moisture ingress than those with a polymer back sheet, because moisture can only enter through the edges. This effect is independent of cell technology; there is no observed difference between PERC cells and HJT cells. This investigation will give significant feedback regarding reliability of façade solar modules to improve manufacturing processes. and increase the acceptance of building integrated PV on the market.