In the SOPHIA workshop, a presentation was made on the first tests of new generation materials to improve the fire resistance of glass-free solar panels.
Within the INCREASE project, parts of the innovations are aimed at building-integrated photovoltaics (BIPV), which consists of integrating solar panels into the building envelope. However, by doing so, the solar panel does not only need to comply with PV standards, but also with building element safety norms, such as fire safety. In Europe, the classification of building materials for fire resistance is based on EN 13501, [AF1] and several tests must be performed to understand it. One of these tests, the flammability test (ISO 11925), studies how a flame spreads vertically across a surface over a period of time. This is to understand how the flame would spread from one floor to another in a building.
At EPFL, we burned different lightweight (LW) modules and observed a sustained flame after removing the flame source. We then decided to burn the different parts of the module separately and found that the fuel for the flame came exclusively from the encapsulant; therefore, improvement of its flame resistance was critical. CSEM produced 7 encapsulants with new formulations. After burning these encapsulants, we were able to demonstrate a ~30% reduction in flame height. Various modules were then produced using either the reference encapsulant or the newly developed encapsulant. It was found that this innovative material actually helped the module to self-extinguish, demonstrating its beneficial effect on the module’s resistance to fire (Figure 1). As the module needs to generate electricity from sunlight, we also investigated how this new material would affect its electrical performance. By measuring the current under illumination before and after encapsulation, we were able to demonstrate that there was no significant impact on the current output, thus showing fire resistance has been improved without affecting the PV module performance.

Figure 1: (a) picture of the module with the reference encapsulant after 3 minutes, a sustained flame can be observed (b) picture of the module with the newly developed encapsulant, the flame self extinguished after 8 second.
Comments