Burned fabric from solar panels on bimini ?

[iGrf]

We are preparing our boat for a (semi)circumnavigation and while taking to a canvas maker who was taking measurements for a new bimini he told us that putting flexible solar panels in a bimini or dodger is not a good idea.


According to him they get too hot and burn the fabric underneath which means that it looses it's shape and water repellent properties.


We've been looking online but cannot find any recommendations against putting flexible panels on a fabric bimini or dodger.


To add to my confusion I mainly find how to guides which encourage people to install them
for example https://www.sailrite.com/How-to-Inst...ls-on-a-Bimini


Any real live advice from people cruising around with them ?


Thanks,
Greg

SV El Burro

[iGrf]

No reaction at all ? so I guess this it not a real issue then

[Pitchondesign]

There have been reports of bimini canvas catching fire as a result of flexible panels overheating. I saw one such instance in the Exumas 3 years ago. I do not know how extensive the problem is.

[GordMay]

See “Why are flexible solar panels catching fire?”
➥ https://www.cruisersforum.com/forums...ml#post2937191

A few RV websites address some of the heat issues, surrounding flexible solar panels:
➥ https://www.gonewiththewynns.com/fle...-issues-review
➥ https://www.thervgeeks.com/flexible-...nels-for-an-rv
➥ https://hi-van.com/do-flexible-solar-panels-overheat/

[iGrf]

Thanks for the replies !

This is even worse than what the canvas guy was referring to.
He mentioned that the underlying fabric would be damaged and lose it's shape because of the heat, not catch fire


First thought would be to glue the panel to a thin alu backing plate which would act as a heat conductor to distribute the heat more evenly (and give the panel some support to avoid cracking).

[Fore and Aft]

iGRF I walked past a boat in the marina at Hervey bay and the solar panel had burned through the Bimini then made a mess of the cockpit before the fire was put out.
It's fairly rare and I see plenty of solar panels on top of Biminis. Normally they are solid and held in an aluminium frame.
Cheers

[tamicatana]

I’m in my fifth year with flex on my bimini. GoPower mounted direct to reinforced patches with grommets, nylon nuts and bolts through the extant holes in the panels

Tips:
—Buy very good quality panels
—Don’t mount such that the panels will see frequent flexure, as that is the cause of breaks which cause shorts
—Install as flat as possible

[soopad00pa]

When I built out my van, I attached flexible panels on the roof and used a layer of corrugated plastic underneath to provide ventilation. Might be worth a look.

[Dogscout]

SunWare in Germany make great panels and have some already attached to fabric that you install with snaps to your bimini. Worth a look

[bgallinger]

I have had two Solbian solar panels sewn on to my bimini for about 6 years now. So far, no leaks and no fires.

[JPA Cate]

I'm wondering if this is at least partly a geographical issue, that the fires occur in the warmer places around the world. Friends of ours here in Tasmania have had no problem with flexible panels and Sunbrella---but it is never seriously hot here (though the locals feel it a lot more than we do when it gets to 30 deg. C.) On the other hand, they go out in shirtsleeves and shorts when it is 5 outside and we are rugged up. Sigh.
Our latitude here is roughly 43 S.
Ann

[Rumrace]

I had factory Jeanneau canvas. My Bimini is fried from 2 100watt panels in sleeves. I put foil reflective under it. Didn’t help much. I use a flexible panel and will continue using them. I don’t want some cantankerous metal art thing on the boat to hold Dinghy and solar panel. I’d like to rebuild the Bimini with a fine wire frame and the stainless steel vinyl covered panels about 2 inches above the canvas. The heat which messed up my canvas is also aging the panels.

I 3D printed a little solar panel holder for the Dinghy battery. Holds a charger and straps on to battery. I bought a cheap panel for $19.00 4.5 watts which will start to fail in 3 years. As they get old I’ve measured these little panels getting hotter. I have the panel so it slides in the holder at a 60 degree angle.

[GordMay]

Originally Posted by Rumrace

I had factory Jeanneau canvas. My Bimini is fried from 2 100watt panels in sleeves. I put foil reflective under it. Didn’t help much...
... I’d like to rebuild the Bimini with a fine wire frame and the stainless steel vinyl covered panels about 2 inches above the canvas. The heat which messed up my canvas is also aging the panels...

I wouldn't recommend a reflective barrier, in that application, either.
Your proposed 2" ventilation gap is probably a good idea, both, for the PV panel, and the Bimini fabric.

Radiant barrier foils can be extremely effective, at lowering radiant heat transfers , but, it MUST have an air space, or void [>½″ - 3/4″], on the reflective side of the radiant barrier, for it to work properly.
The reflective insulation benefit is derived from the interaction of the highly-reflective surface, with the air space above. If the reflective surface is in contact with another building material (solar panel), it becomes a conductor (transmitting the energy by conduction).

Properly placed between your photo-voltaic solar panel, and fabric Bimini top, with a ½ - 3/4" void, or air gap between them, a foil radiant barrier will reflect heat back up to the PV panel (reducing it’s output, etc), but keep the Bimini fabric, and cockpit space beneath it cooler.

If you sandwich the panel, reflector, and Bimini together, and eliminate that air gap, you’ll have conductive heat transfer, accomplishing nothing. Finally, remember that a radiant barrier only works when it is clean and shiny, which preserves its reflectivity. If it gets dirty or dusty, it stops working as a radiant barrier, altogether.

[sck5]

rigid panels on a tube frame attached to the bimini support will avoid all of these problems and likely give you more watts too. Why the insistence on flex panels, esp. if you are going to have to construct something to hold them? Doesnt that negate most of their advantages?

[Rumrace]

These panels are made in gas chambers 3 hour drive away. The back is stainless but wrapped in vinyl. You sure can’t roll them up. You can buy them stuffed in an aluminum frame I have one of those in my office.
So two nice slow curve pair of bands connected to pin mounts on the Bimini tube should work fine. I’m not too knowledgeable adding an airfoil to the back of the boat and bolt something on to the back of the boat seems reckless