The VarioVolt project investigates how solar roof tiles can be designed to combine quick installation, durable performance, and circular design. Current in-roof photovoltaic (PV) systems are slow to install and difficult to recycle, often disrupting the workflow familiar to roofers. This research explores how a new polymer-based PV roof tile can address these limitations through design and material innovation.
Three research questions guided the work: improving installation efficiency and usability (RQ1), selecting suitable materials and production methods (RQ2), and developing a recyclable, waterproof connection between the PV laminate and roof tile (RQ3). Comparative installation testing showed that VarioVolt can be installed two to three times faster than the Alegra 10 solar roof tile and approaches the speed of the traditional VHV Vario. The design achieves this through improved cable routing, colour-coded connectors, and a diagonal workflow identical to that of regular roof tiles.
Material and connection studies identified injection-moulded polycyclohexylenedimethylene terephthalate (PCT) as the most promising base material and snap-fit laminate connections as a circular attachment method. The resulting design demonstrates that efficiency and recyclability can reinforce rather than oppose each other in building-integrated photovoltaics.