5 potential fire hazards and mitigation in photovoltaic systems

PV systems prove themselves continuously as some of the most favored sources of alternative energy with more than 120 GW installed yearly in 2019. PV systems are extremely safe under normal operating conditions if installed and maintained by professionals according to electrical regulations and guidelines. However, with the increasing distribution of different PV systems operating both on the ground, rooftops and even integrated into buildings, the risk of a possible fire occurring where PV systems are installed has to be considered (as is the case with any electrical energy grid).  

Between 1995 and 2012 in Germany, 400 fire cases were reported involving PV systems. 

In 180 cases a single PV component was the source of the fire. To underline the safety of PV systems it must be mentioned that these 180 cases represented less than 0.1% of all fires in Germany during that period. 

PV fire at a factory in Germany

Fire in a factory in Norderney Germany, 8/2013. Damage cost totaling milions of euros (IEA)

Potential hazards of PV systems and mitigation

1. Combustion and pollution

Different components of a PV system are combustible due to their polymer content, for example: EVA encapsulation film and polymer back sheet in modules, polymers in string cables, junction boxes, and inverters. A research led by the German Federal Ministry of Economics and Technology identified that for a 9kWp system with 38 standard PV modules there is up to 60 kg of polymer material from modules alone. Polymers can produce an elevated temperature comparable to the temperature of heating oil (PE: 46 MJ/kg > heating oil: 43 MJ/kg) 

During and after the fire, the PV system can potentially produce emissions in liquid, solid or smoke forms. The general public is safe from dangerous concentrations due to the low amount of hazardous substances existing in PV systems. However, firefighters responding to the incident could be exposed with dangerous levels of metals such as lead (c-Si) or cadmium and selenium if thin-film modules are present in the system. 

Mitigation:  

        • Firefighters must be informed about the existence of the PV modules as well as their location and type in order to plan their actions accordingly and safely.
        • Firefighters must use masks to protect themself from harmful and potentially toxic gas.
        • Debris from a damaged PV site requires professional disposal.

2. Slips and falls

Space limitation on the