How Dangerous Are Home PV Battery Storage Systems Really? A New Study Provides Answers
When battery storage systems catch fire, it regularly attracts media attention. But how high is the actual fire risk of home photovoltaic battery storage systems? A research team at RWTH Aachen has now investigated this question—revealing a striking result: the probability of a fire caused by a battery storage system is just 0.0049% per year.
That is 50 times lower than the risk of a general house fire. The findings were presented in the study “Quantitative Fire Risk Assessment of Battery Home Storage Systems in Comparison to General House Fires in Germany and Other Battery Related Fires”—partly made public for the first time at an event hosted by the German Energy Storage Systems Association (BVES) in Berlin.
How was the fire risk determined?
The researchers relied on publicly available media reports and evaluated them systematically. By the end of November 2023, 36 confirmed fire incidents related to battery storage systems had been reported. Over the same period in 2024, the number had already reached 56—which is not surprising given the sharp increase in installed systems (around 1.6 million home storage systems in Germany).
Important: Only incidents were included in which the fire was demonstrably caused by the storage system itself—i.e., not operating errors or defective battery management systems.
When does it burn—and why?
The researchers found that spring and midday are disproportionately affected:
Seasonal clustering in spring: Batteries may be used more intensively again after a longer period of inactivity (“winter dormancy”).
Time-of-day clustering between 12 p.m. and 4 p.m.: This is when storage systems are typically fully charged—i.e., under high electrical load.
How safe are battery storage systems in comparison?
| Technology | Annual fire risk |
|---|---|
| Battery storage systems | 0.0049% |
| Photovoltaic systems | 0.0014% |
| Electric cars | 0.024% |
| Internal combustion vehicles | 0.089% |
| Tumble dryers | 0.0037% |
| Refrigerators | 0.0012% |
If the risk of home storage systems is calculated per installed capacity, the result is 0.56% per megawatt-hour per year—compared to 0.59% for electric cars. Study lead Mark Junker emphasizes: “Our analysis shows that battery storage systems are a safe technology that does not measurably increase the overall fire risk in households.”
Manufacturers have also responded: Lithium iron phosphate (LFP) batteries—considered particularly safe—are being used more frequently. Recall and replacement programs further increase safety.
Standardized reporting and transparent communication are crucial; however, researchers are calling for improved, standardized reporting procedures and long-term data collection to assess risks even more accurately. BVES also sees the study as a valuable contribution to a factual discussion. Managing Director Urban Windelen states: “The study makes an important contribution to bringing objectivity to the discussion about the safety of home storage systems.”
Conclusion for prospective buyers and operators
According to current research, home PV battery storage systems are very safe. The probability of a fire is extremely low—significantly lower than for many everyday appliances or vehicles.
At TST Solarstrom OHG, we consistently rely on high-quality storage solutions with state-of-the-art safety technology—so you can make the energy transition at home efficiently and with peace of mind.