ᐅ Fire Risk of Photovoltaic Batteries: What Are the Installation Options?

HeimatBauer schrieb:

Battery as a separate cabinet or, as is common, integrated as a home power system?

As nice as the idea sounds, I find it quite impractical in reality:
1. You would either have to move the entire electrical distribution to the ground floor or spend a lot on additional wiring
2. Even as a separate cabinet, but especially as a home power system, it is connected with many cables that no one can disconnect without breathing protection in case of fire
3. Even if points 1 and 2 are solved, meaning the storage is on wheels as a separate cabinet, cable-free, and right next to a ground-level patio door – who would move it out?

Of course, firefighters with breathing apparatus would have to roll it out. But they would prefer a burning box on the lawn or on the street rather than the same box hidden deep in a dark basement corner.

HeimatBauer schrieb:

usually as a home power system

The usual setup is not the home power system itself, but a separate battery connected to the inverter.

bwollowb schrieb:

You hardly ever hear about photovoltaic battery fires, and if anything happens, it makes a very marketable headline.

bwollowb schrieb:

And until recently, I didn't even know anything about LiFePO4 – I’m just a layperson.

LiFePO4 batteries technically cannot catch fire. You could even drive a nail into one and nothing would happen.

bwollowb schrieb:

The comparison with phones, laptops, and similar devices isn’t really accurate. First, we are not talking about batteries of the same size, and second, those are much more common than photovoltaic batteries.

No, the comparison is quite valid. A burning power bank itself is not a big problem, but very few people store them safely; instead, they might keep them on a wooden table, on the Sunday newspaper, in another bag, or similar. THAT is what actually burns.

In the past, oil tanks were installed in masonry containment basins. You could do something similar with lithium-ion batteries. You either let them burn out or flood them with water. There is no middle ground. In case of moving them out on a rolling system, emergency disconnection of power lines could get tricky. Imagine live cables next to a toxic fire...

Therefore: buy a proper quality battery and don’t worry too much. There are many other household items that are much more fire-hazardous.

Simply do without the attic. It’s not cost-effective anyway 🙂

Our utility room is about 10 sqm (108 sq ft) in size. It is, of course, already well equipped with heating, possibly a ventilation system, dryer, washing machine, and shelves/cabinets. How large is a typical battery storage system, and what regulations are there regarding where and how it must be installed? I think I once saw someone mounting a battery storage unit simply on the wall next to a window. It looked like three large car batteries stacked on top of each other. Could that have been a battery storage system? And if so, is it theoretically possible to expand it by adding another “car battery”?

Google "BYD B-Box" or "Pylontech." They generally look like that. Data sheets with dimensions can be found after 2-3 more clicks. I wouldn’t recommend wall mounting them, unless floor space is very limited and urgently needed—in that case, the effort might be worth it. In drywall rooms of prefabricated houses, it usually doesn’t work anyway because they are very heavy.

Karlsson schrieb:
I think I once saw someone mount a battery storage unit directly on the wall next to a window. It looked like three large car batteries stacked on top of each other. Could that have been a battery storage system? And if so, is it theoretically possible to expand it simply by adding another "car battery"?

That was probably me :-) It's a Sungrow SBR096 battery storage with 3 modules of 3.2 kWh each. It can be expanded up to 8 modules. One module weighs about 33 kg (73 lbs).
The "tower of three" measures 625 mm (25 inches) wide, 545 mm (21 inches) high, 330 mm (13 inches) deep, and weighs around 100 kg (220 lbs) including the base and cover.