Experimental study on the fire characteristics of opaque and transparent solar photovoltaic panels

Although solar photovoltaic (PV) panels are widely used in buildings, previous studies mainly focused on optimizing energy performance and studies on their fire characteristics were limited, substantially affecting PV panel design and practical use. Therefore, the fire characteristics and applicability of three types of solar PV panels were assessed by combining experimental data and experts’ assessments. Under fire conditions, the temperature rising rate of the unexposed surface of the non-hollow transparent panel is 1058.3% and 47.2% greater than those of the hollow transparent and non-hollow opaque samples, respectively. The opaque sample's cracking start time and temperature are 186 s and 266.4 °C, respectively, around 44.5% and 41.8% of those of the transparent sample. The opaque sample showed the longest crack of 115.31 m, whereas the non-hollow transparent sample had the largest proportion of glass falling-off area of 8.76%. The fire risks of various PV panels differ under different scenarios. Experimental results and experts’ assessment indicated that hollow transparent PV panels with low fire risk could be used in buildings with high population density, while non-hollow opaque PV panels could be used in scenarios like PV power plants with less population; and the non-hollow transparent PV panels have a considerable fire risk, yet they can be employed in places with low safety requirements or no fire concerns. The obtained research outcomes can guide the selection of solar PV under various practical scenarios.