Photovoltaic solar panels and fires: what risks today?

Electricity self-consumption via the installation of solar panels on the roof has many advantages for private homes, but is this type of installation perfectly safe? This is the question we asked ourselves. Elements of response through several expert opinions.

Between the continuous rise in gas and electricity prices and the tension on fossil resources caused by the conflict in Ukraine, more than ever, the need for energy sovereignty is placed at the forefront in France. This is particularly true for households who can find in the installation of photovoltaic solar panels on the roof of their dwelling a recourse to self-supply electricity and thus become less dependent on “conventional” suppliers.

But is this operation 100% safe? According to figures from the National Observatory for Electrical Safety (ONSE), in 2021, between 20% and 35% of fires in homes were of electrical origin. If the precise cause of these outbreaks of fire is often not obvious to determine, it has been proven that in several cases, the solar panels are not foreign to it. We interviewed several professionals to find out more.

For Christel Ebner, Director of Observatory and Risk Assessment at AQC, "there are risks, given that this type of installation produces direct current electricity, which remains much more dangerous than alternating current. employed in the construction industry. Nevertheless , these risks remain to this day "difficult to quantify" according to David Gréau, General Delegate in charge of photovoltaics at Enerplan.

Where do the risks come from?

According to a study carried out in 2012 by the AQC, the losses noted on installations integrated into the roof came from “70% of sealing problems, 30% of electrical problems of which 10% degenerated into fire. “ Relatively old figures which have unfortunately not been updated to date by the agency.

What are the main risk factors for ignition of photovoltaic solar panels? They are threefold for Christel Ebner: “mainly, the design, implementation and maintenance” of the product .

On the design side, the AQC issued warnings about faulty manufacture of junction boxes (on the back of the panel) on several brands. The defects noted on the installation of the panels generally relate to incorrect installation of the connectors – the male and female connectors must be of the same brand, which is unfortunately not always respected – and connections. Finally, maintenance is paramount, as aging equipment can easily lead to malfunctions over time. The problem? To date, there are no regulations on the subject. Maintenance of photovoltaic solar panels is highly recommended, but not mandatory.

David Gréau, General Delegate in charge of photovoltaics at Enerplan, Syndicat de l'Energie Solaire Renouvelable, adds that risks can also come from the initial electrical network of the building on which the panels are installed. It is therefore up to the professional to make an in-depth inventory of the home before installing the solar panels.

More generally, claims occur most of the time in single-family homes where “unknowing people” live and who are poorly informed by certain unqualified companies.

What about today ?

For David Gréau, today, "there are existing technical rules so as not to endanger the safety of goods and people" and “known and implemented rules of the art” . He specifies that the risks are currently "technically well controlled" with regard to the modules themselves and the inverters, even if "improvements are made in terms of the detection of electric arcs and the implementation of micro- inverters that limit the risks associated with direct current".

At the level of the installation of the solar panels, our interlocutor adds that a major difference lies in particular in the fact that the material is now 99% superimposed. However, the incidents related to the sealing of the panels were formerly directly related to the integration of the frame of the panels, in the plane of the roof. Many risks have thus been avoided in recent years. In addition, this raised installation facilitates maintenance and observation of the correct operation of the installation.

A fairly reassuring story shared by Christel Ebner, who says that the risks are lower over the years. On the insurance side, professionals are now “much more attentive” to respecting the qualifications required for companies installing solar panels. As a reminder, calling on a craftsman with an RGE qualification such as QualiPV from Qualit'EnR is one of the conditions for individuals to be able to obtain various financial boosts for the installation of solar panels such as the self-consumption.

Tips for avoiding disasters

Turning to a certified installer is also "the first thing" to do according to David Gréau to avoid any risk of fire. More generally, it is important to know that any company installing this type of equipment on the roof must be insured for ten-year civil liability.

It should be noted that monitoring the production of its panels is also an important point of vigilance according to Christel Ebner. Indeed, if an individual finds that his panels generate an abnormally low amount of electricity compared to the degree of sunshine and their usual production, he undoubtedly has reason to worry and contact a professional.

Another piece of advice given by Christel Ebner, “use a process subject to technical advice on the Green List” carried out by a group of experts under CSTB supervision. The C2P commission (Product prevention division) within the AQC then intervenes to assess the insurance risk and classify the process deemed safe on the Green List.

In addition, following numerous reports of fires in the early 2010s, the AQC worked in collaboration with EDF and the DGEC "so that in the event of a serial disaster, EDF can more easily find the contracting authorities having installed the equipment" and thus allow faster and more efficient identification of defective panels presenting risks. For David Gréau, another area for improvement lies in the fact of "developing ad hoc training" for electricians, from their initial training, to make professionals aware of the challenges of photovoltaics from the outset and not let them discover them times in the field.

Finally, about 5 years ago, junction box standards evolved to make the material safer.

Conclusion ? The riskzero does not exist, but the conditions for installing and monitoring photovoltaic solar panels seem to indicate a positive improvement in the reduction of fire risks. The main thing lies in raising awareness of good practices, both for individuals and professionals.