flexable solar panel fire

[tjandoverguy]

i have 4 100w panels installed on my bimini
.one had a small burn on one cell
it started a fire and burned a 12 inch hole in bimini.

[Sailmonkey]

What brand of panel?

Describe your wiring/fusing situation?

How are the panels affixed? Can they flap in the wind causing stress cracks?

[thinwater]

Originally Posted by tjandoverguy

i have 4 100w panels installed on my bimini
.one had a small burn on one cell
it started a fire and burned a 12 inch hole in bimini.

Details. Brand? Circuit protection?


Thanks!

[a64pilot]

This is getting not at all unusual, and as they appear to be internal shorts, circuit protection seems irrelevant.
There were two or three incidents when we were at George Town this year to include being what most likely burned a boat that was underway.

I’d be real leery of flexible panels mounted directly on Bimini fabric, however even hard panels have failed in a similar manner, there have been house fires, with usually a build up of leaf debris contributing by adding fuel.

[tjandoverguy]

The panels are 16v wired +to - to a 60w controller .
No fuse.strapped to support in 4 places
With the 4 working the controller showed battery at 12.4
Now with 3 panels battery is 12.8 ??

[tjandoverguy]

Panels came from China eBay 100$ each.ordered and received in 10 days in st criox

[gmakhs]

China , but what brand ?? They are not all the same

[maxingout]

Wow. I did not know that could happen to flexible solar panels.

I can see how the panels could flex on the Bimini when the wind is high and seas are rough.

My greatest fear is fire and explosion when I am at sea. I will skip the flexible solar panels on Exit Only. Maybe get the flexible ones for when I am land cruising in my Land Rovers.

[hellosailor]

"With the 4 working the controller showed battery at 12.4
Now with 3 panels battery is 12.8 ??"

Probably because #4 was defective all along, and now that it is out of the circuit, you are getting higher voltage from the remaining panels.

The question is, do you trust the other three?

[Paul L]

When I replaced the flex panels on my Bimini I order new, cheapo flex panels direct from China (Aliexpress). I got a custom cell configuration to get the shape I wanted and I used aluminium as the backing. These are still thin and light, but much stiffer and less likely to crack cells.

[RNWilson]

It's possible for anything electrical or electronic to catch on fire if it's poorly designed defective or installed improperly. This would include any solar panels charge controllers battery chargers LED lights or any electronic device of any kind. I just try to buy well-known brands with a track record and hope for the best!

[Cpt Pat]

That fire was an implementation error based on overconfidence in the mechanical resilience of the panels and an absence of electrical fault protection.

I have my "bendable" flat panels affixed to rigid surfaces (so they don't flex), individually fused, and connected in parallel through individual Schottky steering diodes so a short in one panel can't draw fault current from the entire array. In this case: no counter-flexing support, no fuses, no steering diodes.

"Flexible" is a misnomer. Excessive flexing will kill these panels -sometimes catastrophically (as shown above) - due to fatiguing of the internal inter-cell bonding wires. The panels should be called "bendable." They can be bent IDEALLY ONLY ONCE to a slight and gentle camber. The minimum camber radius should also be specified.

Sorry folks. You can't just let the panels flap in the wind. And when they are mounted on sailboats, yes, one would hope, there IS wind. The aluminum bonding wires will only take so many bends before failing (sometimes shorting). They'll "luff" themselves to death in no time!

[FlyingScot]

Solar panels, wiring and controllers aren't were you want to buy the cheapest stuff. A fire on a boat could easily result in YOUR death and the death of others.

Thanks for sharing and hopefully others will learn from your results.

[Cpt Pat]

Originally Posted by FlyingScot

Solar panels, wiring and controllers aren't were you want to buy the cheapest stuff. A fire on a boat could easily result in YOUR death and the death of others.

Thanks for sharing and hopefully others will learn from your results.

Agreed. Besides sea monsters, I can't think of anything scarier at sea than a fire.

When designing a solar array, you have to think about all the possible failure modes. A single panel shorting in a parallel-connected array will carry all the current from the entire array without the provision of steering diodes in series with each panel. Yes, the diodes cause some loss, but it's minimal (Schottky diodes have a voltage drop of only about 0.3 volts) and the steering diodes also block "back" current absorbed by a shaded panel.


For smaller panels, these should do the job: https://www.amazon.com/Volt-Schottky.../dp/B0056RHMCG

[sailinglegend]

We have two 150 watt Solbian panels which are re-inforced on the back with sail batterns. They are attached with about 16 Tenax push lock fasteners each and have hardly any flex even in F8 winds. We can easily take them down if stronger winds are forecast - even in the marina, and stored under the bed. This operation is usually the most dangerous for flexible panels which will bend past their design spec just getting them off and down below - hence the re-inforced backing.

In this situation each panel should go to their own solar controller - Victron have a fantastic cheap range with free apps for an iphone to view and control their charging.

Also any new panels should immediately be tested for the correct open circuit voltage and when connected their charge current should be measured one at a time. If being paralleled to one controller they should all show very similar results.

As suggested above it could be one was faulty right from the start. Now with only three panels 12.8v doesn't sound very high - in sun they should eventually get depleted batteries back up to at least 14.4v.