In order to minimize the risks of fire accidents in large scale applications of solar panels, this review focuses on the latest techniques for reducing hot spot effects and DC arcs. The risk mitigation solutions mainly focus on two aspects: structure reconfiguration and faulty diagnosis algorithm.
The hot spot effect and aging of PV panels were found responsible in previous fire accidents can be caused by the dust density around the PV array, the ambient temperature, and the material structure of the PV array. Preventive solutions to the fire accident can be distinguished into solar panel reconfiguration and fire fault detection algorithm.
Hydrogen compounds such as HF and HCL that are toxic are produced during the fire accident of solar panels. In 2009, 1826 PV modules with a generation capacity of 383 kW solar PV arrays were damaged in a fire accident in California, USA .
The studies include recommendations to minimise the use of combustible materials as roof covering beneath solar panels to stop the spread of a fire. Firefighters need to be equipped with the correct training when battling a fire that involves photovoltaic systems.
According to , approximately 51% of the PV related re accidents is related to installation errors or poor quality of PV modules, which further causes cable faults on PV modules. On the contrary, the hot-spot effect is liable for a relatively lower percentage of the solar panel re accidents.
Existing approaches to avoid solar PV fire accidents mainly include preventive actions. The preventive actions include array recombination and detection algorithm research. The studies [40-50] illustrate the reconfiguration of PV modules or PV arrays, and the studies [51-78] introduce algorithm to detect the faulty PV modules. FIGURE 9.