Repair options for PV modules with cracked backsheets

Abstract

Abstract The paper provides a comprehensive overview of possible strategies for the repair of cracked polyamide‐based backsheets. A repair process has been developed that comprises the following steps: (i) cleaning, (ii) pretreatment, and (iii) repair process (crack filling and sealing). The important topic of long‐term reliability is still under investigation. Two different repair strategies have been addressed in this article: (i) repairing damage by restoring electrical insulation properties and (ii) preventing further growth of the surface near microcracks. From a technical point of view, several of the repair solutions examined met the defined requirements for compatibility and applicability. On the one hand, repair tapes/films sealed the surface and only covered the cracks. The adhesive did not penetrate into the cavities that had opened through the cracks in the backsheet material. Therefore, adhesive tapes/films are not suitable for the repair of large‐scale damage and the permanent restoration of the electrical insulation properties. On the other hand, several repair coatings based on polyurethane, epoxy, silicone and synthetic rubber were identified which, after a two‐step application process, showed complete crack filling and sealing of the surface. The required insulation resistance of the aged modules could be restored. Since the new and artificial reliability tests are still running, no final conclusions on the long‐term behavior of the repair and its life‐extending effect of PV modules can be drawn at the moment.

Keywords

• cracked backsheet
• electrical insulation
• polyamide backsheets
• PV modules
• repair