25. Jan 24
New report: Sweeping of fireplaces
12. Jan 24
Do EVs burn more frequently than fossil cars?
20. Dec 23
New report: Fire safety during construction and rehabilitation of buildings
12. Dec 23
New report: Fire for Christmas
21. Nov 23
Recording of autumn webinar

New RISE-reports: Solar cell installations on buildings

In recent years, RISE Fire Research has carried out several studies on fire safety in solar cell installations as part of a project series on energy-efficient buildings and fire safety (EBOB). Two reports with the results from the project "EBOB - Solar cell installations on buildings" have now been published.
The aim of the project has been to answer the following four research questions:
  1. How do wind speed and air gap size affect the fire development in the cavity between the solar cell module and the underlying roof structure, and how do these factors affect the extent of damage to the underlying roof structure?
  2. How do solar cell modules affect a fire on a realistic, Norwegian, pitched roof?
  3. What work is ongoing in Europe and internationally to developing test methods for fire technical documentation of photovoltaic modules, and how should this be implemented in Norway?
  4. How should fire service personnel be secured in their work when the fire includes solar cell installation? In this research question, larger installations beyond residential houses and detached houses are also relevant, including larger buildings, flat roofs and BIPV.
The main findings from the experiments are that solar cell modules mounted parallel to the roof surface on pitched roofs can affect the fire dynamics of a fire on the roof surface. It was found that both the length of the damaged area on the roof and the temperature rise inwards in the roof (below the chipboard) increased when the distance between the simulated solar cell module and the roof surface decreased. Furthermore, the findings indicate that there is a relation between the size of the gap between the roof surface and the solar cell module, and how large initial fire is needed for the fire to spread. A larger distance between the roof surface and the solar module requires a larger initial fire for the fire to spread. The temperature increase inwards in the roof structure was not large enough in the experiments performed to pose a danger of immediate fire spreading inwards in the structure.

Work is ongoing internationally on the development of test methods for fire technical documentation of solar cell modules. This work has so far not resulted in new standards or procedures that can be implemented in Norway.

Information has been found from various guidelines and reports on what equipment and expertise the fire service needs to secure their efforts. It is important that the fire service has sufficient knowledge about the working principle of a solar cell installation, so that they understand that parts of the installation can conduct electricity, even if the switch-off switch is activated. The fire service must also be given training in how to handle a fire in a building with a solar cell installation, as well as what protective equipment and tools are needed. The answers from the various fire services to a questionnaire show that solar cell installations rarely are included in the risk and vulnerability analyses (ROS analyses). As a consequence, they do not currently have good enough training and knowledge about handling fires in buildings with solar cell installations.

Our questionnaire also shows that it seems somewhat unclear to the fire service what responsibility they have in the event of a fire in solar cell installations. This should be clarified, and in cases where solar cell installations pose an increased risk, the fire service must be provided with resources so that they have the right equipment, the right competence, and the right staff to handle such fires.

The main report "EBOB - Solar cell installations on buildings. Fire spread and safety for the fire service." summarizes the entire project. More complementary details from the experiments carried out can be found in the technical report "EBOB - Solar cell installations on buildings. Experimental study of fire spread in cavities behind solar cell modules on sloping roof surfaces”. This project was carried out on behalf of the Norwegian Directorate for Civil Protection (DSB) and the Norwegian Building Authority (DiBK). The project has also received funding from project 4-4 in the Fire Research and Innovation Center (FRIC). FRIC is financed by all the partners as well as the Norwegian Research Council (FIRE SAFETY programme, project number 294649).

The main report here: (pdf)
Read the technical report here: (pdf)
Both reports are in Norwegian with English summary.