Since mid-June, at least ten fires involving buildings equipped with solar installations or associated storage systems have been reported in Switzerland, Germany, and Austria. This striking series of PV-related fires largely coincided with an extraordinary heatwave across Western and Central Europe; consequently, high temperatures are considered a potential trigger or contributing factor. However, investigators have not yet established a common causal link. Identified causes to date primarily include technical defects, overheated storage units, and as-yet unexplained faults. The consequences range from destroyed modules to uninhabitable homes, extensive property damage, and injuries to firefighters.
Four fires in five days in Switzerland alone
On June 24, the roof of an apartment building equipped with a photovoltaic system caught fire in Laax. Twelve residents had to leave their apartments as a result. On June 26, another fire broke out at an apartment building in Zizers; there, too, flames were seen shooting from the area of the solar roof. Investigations into the causes of both incidents were initially ongoing.
Image: Shutterstock
On June 29, roofs equipped with solar panels also caught fire in Disentis and at the secondary school building in Elgg. In Disentis, the fire department had to extinguish flare-ups several times and monitor the building until morning. In Elgg, by contrast, the damage amounted to several hundred thousand francs. No one was injured in these four Swiss incidents. Nevertheless, the clustering of these events in such a short period remains striking, even though it does not imply a common cause.
Further PV fires occur during extreme heat
Germany also reported several fires involving photovoltaic systems in quick succession. In Waiblingen, a total of 16 modules on a commercial roof caught fire on June 19; police suspected a technical defect. Earlier, on June 14, the roof of a sports hall had burned in Augsburg; initial estimates placed the damage there between 500,000 and one million euros. Additionally, systems caught fire in Gorintschach and Hofkirchen im Traunkreis, Austria.
On July 5, the storage unit of a photovoltaic system caught fire in Bentwisch, near Rostock. Police initially suspected overheating. An explosion also occurred during the emergency response, resulting in minor injuries to three firefighters. On July 9, a fire broke out involving a rooftop system in Leibertingen. The flames destroyed a garage building and rendered the adjacent residential house uninhabitable; the damage exceeded 500,000 euros.
Heat remains a plausible contributing factor
The clustering of PV fires during the heatwave is notable. However, it demonstrates neither a statistical increase nor a direct causal link to high ambient temperatures. At the same time, Western Europe experienced its hottest June on record. Under intense solar radiation, solar modules can heat up significantly more than the surrounding air. This also increases the thermal stress on connectors, cables, junction boxes, and inverters.
Properly installed systems should not catch fire solely due to summer heat. However, components that are already damaged or poorly connected can heat up further. Contact faults therefore promote the formation of hot spots and electrical arcs. In battery storage systems, high ambient temperatures can also exacerbate existing defects. Investigations will need to determine whether the heat actually contributed to specific PV fires. Owners should therefore have error messages and unusual drops in energy yield checked. Inspections following storms, hailstorms, or periods of extreme heat may also be advisable.
Author: Blackout News
Sources: Tagesanzeiger (09.07.26) – Presseportal (09.07.26) – NDR (06.07.26) – Feuerwehr Florian (05.07.26) – Mein Bezirk (02.07.26) – Feuerwehr Friessnitz-Rosenbach (26.06.26) – SWI Swissinfo (25.06.26) – Watson (24.06.26)