Review shows significant numbers of fires in PV on buildings, but inadequate reporting and poor data on fire and smoke risks. Over 300 publications on PV fire safety were reviewed. Two reports from Italy and Germany suggest 1600 fire incidents per 590 000 PV installations and 430 per 1.3 million respectively (numbers are not per year, so not comparable). Different factors can cause fire in PV systems: physical degradation, overheating, arc faults, faults in inverters, by-pass diodes, bridging and arrays or power unit, as well as fires starting elsewhere in the building. Although the semi-conductor in PV panels is silicon, other layers and backsheets are generally made of flammable polymers, as are cables and electronic structures and housings. There is today limited published research on PV fire behaviour, but with some increase over recent years. In particular, research is lacking on fire behaviour of panels integrated into the building structure (compared to attached panels), on smoke emissions and on fire propagation and heat transfer.
“A state-of-the-art review of fire safety of photovoltaic systems in buildings”, M. Arem et al., Journal of Cleaner Production 308 (2021) 127239 https://doi.org/10.1016/j.jclepro.2021.127239