Research from the Norwegian University of Science and Technology (NTNU), in collaboration with the Fire Research and Innovation Centre (FRIC), and RISE Fire Research, has shown that increasing the distance between the roof and modules can prevent solar panel fires.
The risk of solar panel fires increases as more are installed. In 2022, the Norwegian Water Resources and Energy Directorate (NVE) registered a doubling of solar power systems installed and connected to the power grid.
However, the researchers discovered that an extra three centimetres can prevent this risk.
Most solar panel fires occur in new systems
The research showed that the risk of a solar panel fire is higher in new systems due to errors and weaknesses in the installation.
There is also reason to believe that the fire risk will increase towards the end of the system’s service life if the installation’s damage and wear and tear are not fixed. Since most installations are still fairly new, we don’t know much regarding these causes of fire.
“Many fires occur when a system is brand new, and they get the first week of proper sun. This can trigger faults or weaknesses in the system. We see this in data from other countries and in many of the fires that have occurred here in Norway,” explained Reidar Stølen, who led the research.
“I think that quite a few solar panel fires could have been avoided if the installation had undergone better checks before the system was put into operation.”
How does increasing the gap lower fire risks?
The experiments show that the risk of fire spreading is significantly reduced by increasing the distance between the roof and the modules – provided that the initial solar panel fire is not too fierce.
Stølen and his colleagues found a significant difference in the spread of fire by increasing the distance from 6-9 cm. Other researchers have found similar differences in the spread of fire by increasing the distance from 8-11 cm or from 17-20 cm.
Stølen said: “Small changes in the gap between the roof and the solar panel module can result in big differences in how fast the fire spreads.
“If the distance is greater, the structure can withstand a larger initial solar panel fire.”
The researchers have also investigated how solar panel modules affect fire safety when installed on facades. A wall measuring four by six metres and covered with solar panel modules was exposed to flames equivalent to those which can come out of a window in the event of a flashover.
Fire spreading up facades can also pose a greater risk of the fire spreading to different floors compared with a fire starting on a roof. Facade fires can spread to large parts of the building within a very short period of time.
Stølen concluded: “Our results show how important it is to pay attention to these types of details when installing the modules.
“Designers of the systems for new or existing facades must take these factors into consideration in order to prevent solar panel fires from escalating.”
