flexible vs rigid solar panels

[FuneSF]

Thank you very much. I like how you set those up.

[Smokeys Kitchen]

Originally Posted by FuneSF

Thank you very much. I like how you set those up.

There is not a good photo of it in the 4 I posted, but there are nylon spacers between the panels and the greenhouse sheets to allow some airflow under the panels for cooling.

[bcboomer]

Originally Posted by Smokeys Kitchen

There is not a good photo of it in the 4 I posted, but there are nylon spacers between the panels and the greenhouse sheets to allow some airflow under the panels for cooling.

Looks good but I wonder why the greenhouse sheets are needed. Couldn't you space the rails to the outer edge of the panels and fasten them directly?

[donradcliffe]

With flexible panels, it isn't just about reduced output and limited life. This panel was on top of a soft bimini, and the bimini sunbrella was on fire. If we hadn't been sitting in the cockpit, this boat would have been a total loss.

[bcboomer]

It looks like there was too much flexing going on. The panel broke in the middle of the cells.

Flexing is the biggest cause of panel failure.

They are only designed to be mounted in a curve, not flex.

If they are mounted on fabric that isn't 100% rigid then I would choose aluminium backed panels or put them on a thin sheet of aluminium.

[Smokeys Kitchen]

Originally Posted by bcboomer

Looks good but I wonder why the greenhouse sheets are needed. Couldn't you space the rails to the outer edge of the panels and fasten them directly?

We could not. The side rails that the main rails are fastened to are fairly short and the long rails are spaced out as much as I could get them. The greenhouse sheets and the panels hang over the long rails by about 6 inches on the front and rear. The panels themselves only have attachment points at the corners. We also put spacers between the panels and sheets to allow for airflow

(if more questions pop up we will get to them in @ a week)

Ron

[Rohan]

Originally Posted by donradcliffe

With flexible panels, it isn't just about reduced output and limited life. This panel was on top of a soft bimini, and the bimini sunbrella was on fire. If we hadn't been sitting in the cockpit, this boat would have been a total loss.

That looks like a problem with the solar controller, not the panels. Did you have a fuse installed with that?

[Rohan]

I also asked this same question over a year ago, and got varied responses. I ended up buying flexible panels. Apparently in the past, flexible panels haven't lasted as long, but the truth is, the newer ones are much better quality. So far, after 8 months, I am very happy with mine, but we will see what happens.

They were lighter, cheaper, and I was able to install them with velcro and a sewing machine, rather than having to ask a third party build a frame. Another advantage is that they have a slight curve to them, which catches the sun better.

I do have one hard panel, which is a portable one designed for camping. I don't see any difference in performance. However, even if there is a difference, compare the 100 watt flexible solar panel that only weighs 4 lbs vs a 100 watt hard panel that with frame that weighs and costs three times as much.

[donradcliffe]

The one year old panels which caught on fire cracked where they went over one of the bimini bows. The problem was not the Victron controllers.

The old bimini was replaced with a stainless tubular frame and 10 Renogy 100 watt hard panels, where the panels function as the surface of the bimini. A nice looking solution which will still be putting out good power a decade from now.

[bcboomer]

Originally Posted by donradcliffe

The one year old panels which caught on fire cracked where they went over one of the bimini bows. The problem was not the Victron controllers.

Every manufacture I've seen specifically warns you to not mount them that way. You shouldn't blame the panels. It was self inflicted.

The new setup looks nice but you've added 140 lbs of weight up high.

[David B]

Originally Posted by bcboomer

Every manufacture I've seen specifically warns you to not mount them that way. You shouldn't blame the panels. It was self inflicted.

Totally - no surprise!

[chasfgr]

Originally Posted by rwidman

I keep a copy of the West Marine catalog near the toilet and have spent a lot of time reading through it.

According to West Marine (and they sell both kinds), rigid solar panels produce considerably more power per square foot than flexible panels. That information would be enough for me to make my choice.

Unless you cannot use rigid panels for some reason, that should be your choice as well.

There are significant differences, even on the loo!


Flexible and rigid panels are about the same price, compared in watt output.
You nee86F)d to mount glass panels, with adequate cooling as well as safe from pressure,
At 30 degrees from the equator, the surface temperature of glass panels can get to 80C (for those stuck in the 19th century that's nearly 90F).

[Seabeau]

As I said previously, I purchased the cheap Nature Power semi-flex, walk-on panels, but only after reviewing and acknowledging their shortcomings. Overheating was their main complaint. To solve that, I simply mounted each panel on top of 8mm poly. double walled greenhouse glazing with screws directly to my cabin top. The dual glazing provides plenty of ventilation beneath the panels. My boat in is Semi-tropical GA. USA and summer air temperatures easily reach 99 to 100 degrees F. Four years later, no measurable hot spots on top or bottom of the panels and output remains within specs. Incidentally, I try and not use the measuring system devised by supporters of the most vicious and murderous regime in 19th century European history prior to the advent of the Nazi's in WW2.

[Maia]

Here is a short field report:
In March 2019 we installed 4 semi flexible solar panels from Shinesolartech (Shenzhen China). Each panel should have 250Watt peak. After 2 years, 2 panels are without any output, zero power. The other two have only about 25% output. On one panel there are burn marks. We had hoped that we would not have the typical problems of PET panels with these ETFE coated panels, but unfortunately we were very disappointed.
The promised warranty is not available. The company shinesolartech simply does not answer anymore. We will definitely not install flexible panels on our boat anymore.
Cheers
Maia

[goboatingnow]

My friend had flexibles on his RV , same issue. Burn marks and dead panels after 2 years.

My rigid panels are 6 years old and still going strong