Fire risk posed by solar panels

[Jammer]

There have been a number of solar panel fires at commercial solar installations. A few fires and some near misses have occurred on boats.


A number of solar panels have been recalled by their manufacturers due to fire hazards, including Renology flexible panels and some Bosch rigid ones.


There have also been a number of fires originating in combiner boxes on systems where these are used.


Have you made any changes to your solar system to address fire safety? Beyond ordinary care and electrical best practices, were there any steps you took during the design, selection, and installation process to mitigate fire risk?

[SailFastTri]

Renology is really spelled Renogy.



No, I added fuses near the panels (between panel and charge controller). That's all.

[Pelagic]

It would be interesting to know the causes of those fires?

[hellosailor]

What Pelagic said. Solar panels generally were not known to self-combust. Some of the flexible panels have overheated in hot spots, especially when flush mounted, and the plastics used in them have combusted. And fires in the combiner boxes or other electronics...that's not the solar panel, that's simply electronics. Some components can be sourced as flame-resistant.

Just knowing that some installations, of unknown reason and unknown variation, have been in fires...that's like saying kitchen stoves are dangerous, they cause fires. (And I'm told that in ancient Rome, home cooking fires were actually illegal, they were afraid the city would burn down. Folks took their food to the local bakery, where the ovens were safe and someone else dealt with ashes.)

[Jammer]

Originally Posted by Pelagic

It would be interesting to know the causes of those fires?

Typically high-resistance connections leading to localized heating. Either internal to the solar panel, or in a combiner.

[thomm225]

Solar is much safer than the other ways of power generation at least for us small boat sailors with 200 watts or less

I'm using 14 gauge wire due to the low current

[JJDPHD]

My only experience with solar panel related fire was fire and melt down of my solar controller after a lightning hit entering at one of my 85W panels, which also wiped out the solar panel. Controller was isolated and nothing else caught fire, but all my electronics were crispy. Replaced one of two panels and all is functioning well - after replacement of all my electronics. They needed upgrade anyway???

[btlflpztk]

JJDPHD - Benevolent lightning?

[btlflpztk]

hellosailor - Too bad ancient Londoners did not learn that policy from those wise old Romans. Oh %#$, London fire was started by a bakery

[Checkswrecks]

There've been a number of fires caused by cheaper Chinese panels - And btw China makes some really good ones too, so this is not bashing.


Underwriters Laboratories has done a lot of research and has some resources on the subject. DO look for UL certification.


https://sinovoltaics.com/learning-ce...certification/
https://www.solarpowerworldonline.co.../array-aflame/
https://ulfirefightersafety.org/rese...c-systems.html

[StevenMeredith]

At the voltages on a boat the risk is low, on a commercial site where you have several solar modules in series getting up tp 600V or 1000V then several strings in parallel there is quite a bit of potential and current to cause damage if there is a fault. On a boat with one mppt per module or pair the risk is low. Hot spots due to internal resistane in the module can arise but modules are designed with materials to smolder and not ignite, so you would have some brown spots and have notice there was an issue. Check your connectors for corrosion, disconnect when the circuit is open, check wires for damage, everything else should be non user servicable.

[ArmyDaveNY]

Originally Posted by Checkswrecks

There've been a number of fires caused by cheaper Chinese panels - And btw China makes some really good ones too, so this is not bashing.

Underwriters Laboratories has done a lot of research and has some resources on the subject. DO look for UL certification.

https://sinovoltaics.com/learning-ce...certification/
https://www.solarpowerworldonline.co.../array-aflame/
https://ulfirefightersafety.org/rese...c-systems.html

I wondering about this on the manufacturing side. What I have found is that while communist China is well known for knock offs, they are more than capable of producing quality products when supervised properly. These knock offs are a real problem.



My brother in law's company has a factory over there and he was telling me about entire cities that are dedicated to producing illegal knock-offs. I also have a few clients who have to deal with this. Their factories there have a lot of inspectors and also ensure high quality material, but the illegal knock-offs don't monitor the work to the same standard. Those companies often use substandard parts too.


The UL listing is a good start, but even here one must be careful. A lot of the knock off companies will print UL certifications even though they are not UL certified. Buying from a reputable dealer helps since they are more likely to stand by their product even if they themselves have been duped.

[lhusty]

Originally Posted by thomm225

Solar is much safer than the other ways of power generation at least for us small boat sailors with 200 watts or less

I'm using 14 gauge wire due to the low current

If the output of the solar panel is 12 volts, you are overloading #14 wire. 200\12==
16.67 amps. #14 shouldn’t be loaded more
Than 12 amps

[thomm225]

Originally Posted by lhusty

If the output of the solar panel is 12 volts, you are overloading #14 wire. 200\12==
16.67 amps. #14 shouldn’t be loaded more
Than 12 amps

Well, here's my setup and all my panels are 12 volts.

I have two (2) 20 watt panels with each having 14 gauge wire going to a PWM controller in parallel at times.

I have a 65 watt panel with 14 gauge wire going to an MPPT controller …. at times

I have a 50 watt panel going to the MPPT Controller also.

All these panels have their own 14 gauge wire. I found the wire in the trash at work.

I'm not seeing a problem.

[andreas.mehlin]

Originally Posted by lhusty

If the output of the solar panel is 12 volts, you are overloading #14 wire. 200\12==
16.67 amps. #14 shouldn’t be loaded more
Than 12 amps

Well...
When talking about 12v panels, they don't put out 12v....more something around 18v. So if you would assume a 200w panel put out 100% (which it more or less NEVER does), it would be something around 11A.