Does anybody know if flexible solar panels have the same performance and longevity as equivalent fixed panels ?.

My experience is that the flexible panels are not as robust as the fixed panels. I have progressively destroyed all my flexible panels (of different brands), but the solid ones are all fine. In fact I dropped a fixed panel in the water. A diver got it out for me about a month later and it still worked !
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I have semi-flexible solar panels fitted to the top of my bimini that are still producing enough to keep the batteries nicely topped up after 5 years of service.
They are scuffed and lost their initial gloss finish within 2 years due especially to the fact that the warm panels make a comfortable platform for seagulls to crap on.
I am sure that rigid glass panels would last longer and look better but I'm not sure how well they would fit onto a flexible surface like the top of a canvas bimini.

Yes Gravy, that's why I'm asking. I'm considering putting a couple of panels on the bimini, they are so much lighter than the fixed panels and I wouldn't need a frame for them. I reckon I can couple them together and attach them to the bimini frame with suitable strapping and save a whole lot of weight swinging up there.

Hey Sam,

When it comes to flexible panels, there are flexible panels and flexible panels!

Really, it comes down to cost - you can get an equivalent quality & power solid panel for far less than a flexible one.

That said, you're definitely able to mount the flexible ones nigh on anywhere. Newer ones also have a ETFE layer, rather than PET - so they're a bit tougher and allegedly a bit better at absorption. It also means they're not glossy, instead they're a bit dimpled and easier to walk on (and look at!). That said, the old ones that were on there still pumped in power until I removed them and they looked pretty hacked up, so you'd be surprised how much abuse they can take before they stop working.

I bought these off eBay here: https://www.ebay.com.au/itm/30W-12V-ETFT-Mono-Flexible-Solar-Panel-Battery-Charger-For-12V-Caravan-Boat-Home/223557041100?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649 but the main reason I chose them in particular was because of the physical width I needed to fit them in. I'm sure you can probably go for bigger ones than that.

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samsturdy said..
Yes Gravy, that's why I'm asking. I'm considering putting a couple of panels on the bimini, they are so much lighter than the fixed panels and I wouldn't need a frame for them. I reckon I can couple them together and attach them to the bimini frame with suitable strapping and save a whole lot of weight swinging up there.

Sam, from what I have read, flexible panels are of a variable quality, as in the better ones are not cheap but if they are mounted in such a way that they get ventilation underneath they will last and perform very well . Horses for courses as they say but you will pay more for good ones and they will probably not last as well as the rigid variety.

one of the big gotchas is assuming that the panels will put out the theoretical maximum rated power.

there is variance in the manufacturing process and the resulting panels are graded after manufacture (the same process happens with computer CPUs and RAM). generally speaking, the better panels cost more. cheap panels are less likely to produce the theoretical maximum outputs.

The ones I'm looking at are 100 watt monocrystalline from RTM $329 about $100 dearer than fixed panels.

You also need to understand and accept that putting the panels somewhere where they are going to have some shade some or all of the time, this video demonstrates it quite well.

Sam, the panel I used is a Welink semi-flexible 80w, 15v panel that I found from an eBay supplier for A$300. It weighs about 1kg and measures 933 x 540 x 3 mm.

Photos and details of other Jeanneau SO349 owners' experience at jeanneau349.freeforums.net/thread/242/solar-installation

Thanks Gravy, at $329 for 100 watts then the pricing sounds right. The size is 1050 x 540 x 3mm. I'm charging 2 x 105 AH batteries,
running a fridge. Should I go through an MPPT regulator ?.

I already posted this video but if you didn't watch it's worth a watch, he finds out that the new panels produce half the power they are quoted .

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samsturdy said..
Thanks Gravy, at $329 for 100 watts then the pricing sounds right. The size is 1050 x 540 x 3mm. I'm charging 2 x 105 AH batteries,
running a fridge. Should I go through an MPPT regulator ?.

Yes, Sam. If you click on the link I provided, you will discover that I used a TopRay Solar TPS 1230 30A charge controller but another owner suggested that a decent MPPT controller will increase the output by 30%.

But I doubt very much that one 100w solar panel will even go close to running a fridge. I only use mine to keep the batteries fully charged while left on a swing mooring.

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Gravy7 said..

samsturdy said..
Thanks Gravy, at $329 for 100 watts then the pricing sounds right. The size is 1050 x 540 x 3mm. I'm charging 2 x 105 AH batteries,
running a fridge. Should I go through an MPPT regulator ?.

Yes, Sam. If you click on the link I provided, you will discover that I used a TopRay Solar TPS 1230 30A charge controller but another owner suggested that a decent MPPT controller will increase the output by 30%.

But I doubt very much that one 100w solar panel will even go close to running a fridge. I only use mine to keep the batteries fully charged while left on a swing mooring.

I'm using two coupled together on the bimini Gravy. 200watts should run a small fridge. I was considering two
120 watt fixed but the size plus a frame to sit them on etc was just too much.

Sam I have 300w of panels cheap fixed ones a 115 ah battery, no engine charging and am successfully running a 60l fridge, electric head,led lights etc on a full time basis

Here is my first week using a mppt solar charger, in rainy cloudy conditions I very rarely see full charged battery's from the solar I receive. My opinion is have more solar than battery amp hour. Eg I have 500 watt of solar and 700 or so amphr of battery's it never keeps up unless I I use candles and eat can food.

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southace said..

I already posted this video but if you didn't watch it's worth a watch, he finds out that the new panels produce half the power they are quoted .

I have a 120w monocrystalline semi flex panel from Itech World which I keep on board for extra. Its more like an 80w and it really needs to be directed totally toward the sun,,, the slightest shadow on it kills it. Never have needed to use it as my wind turbine and 44w permanently mounted ridged panel take care of my power usage.
It may be that my PWM charger is not getting the most from it.

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samsturdy said..

I'm using two coupled together on the bimini Gravy. 200watts should run a small fridge. I was considering two
120 watt fixed but the size plus a frame to sit them on etc was just too much.

it really depends on the fridge - if it's low efficiency then 200W of solar may not be enough. keep in mind that ideally you don't want to run your batteries down below 50% charge.

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samsturdy said..

Gravy7 said..

samsturdy said..
Thanks Gravy, at $329 for 100 watts then the pricing sounds right. The size is 1050 x 540 x 3mm. I'm charging 2 x 105 AH batteries,
running a fridge. Should I go through an MPPT regulator ?.

Yes, Sam. If you click on the link I provided, you will discover that I used a TopRay Solar TPS 1230 30A charge controller but another owner suggested that a decent MPPT controller will increase the output by 30%.

But I doubt very much that one 100w solar panel will even go close to running a fridge. I only use mine to keep the batteries fully charged while left on a swing mooring.

I'm using two coupled together on the bimini Gravy. 200watts should run a small fridge. I was considering two
120 watt fixed but the size plus a frame to sit them on etc was just too much.

Sam, I have a total of 190 watts and it runs the built in fridge, led lights stereo etc no problems. It struggles when I add a 40 litre portable freezer in to the mix though.

Thanks for the replies. Initially it'll be a portable Waeko but I'm eyeing off a fixed front opening fridge with a small freezer. I'm
told the power draw is 3 amps and I think it's a Waeko too. It's not a big fridge but will give me all I need.

200 watt fixed panel through a 30 amp a MPPT reg charging a 540 amp bank. This runs a BD35 fridge compressor on a mooring with no issues. I'm leaning toward another 200 watt panel for cruising, it work ok but it's nice to have a little more reserve, TV, lights etc when living on board.

Wow, that's some panel Stockie. Do you know the size offhand ? I'm a bit space challenged.

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Stockie said..
200 watt fixed panel through a 30 amp a MPPT reg charging a 540 amp bank. This runs a BD35 fridge compressor on a mooring with no issues. I'm leaning toward another 200 watt panel for cruising, it work ok but it's nice to have a little more reserve, TV, lights etc when living on board.

540A bank?
Swoon....

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woko said..
Sam I have 300w of panels cheap fixed ones a 115 ah battery, no engine charging and am successfully running a 60l fridge, electric head,led lights etc on a full time basis

Very efficient setup with a 115Ah bank Woko, you've got it sorted. Can you still hack it without engine when you have one or two overcast days, when panels deliver less than usual ?

Sam, I had 2 x 200watt rigid panels, 30amp MPPT controller and two replacement 200Amp Hr house batteries installed in Dec 2017. On a good day with clean panels I have seen 20 amps going in when the batteries were first charging and regularly have excess charge going to the batteries while running the normal systems. We run a dual compartment fridge/freezer, 40 litre waeco fridge, Electric toilet, stereo, lights , TV/video, all navigation including dual B&G plotters and electric ram auto pilot and typically we are down to 80% each morning. Normally on a sunny day we are at full capacity by late morning or under two hours of engine time, while heating the water for a shower etc will bring us back to 100%.

As far as controllers are concerned, what is it for much extra cost, does an MPPT have over a PWM and would I need to go
this expensive to just do what I've indicated ?.

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Karsten said..

woko said..
Sam I have 300w of panels cheap fixed ones a 115 ah battery, no engine charging and am successfully running a 60l fridge, electric head,led lights etc on a full time basis

Very efficient setup with a 115Ah bank Woko, you've got it sorted. Can you still hack it without engine when you have one or two overcast days, when panels deliver less than usual ?

Yep no problems there, it comes down to useage, ie I don't run a tv, pressure pumps or half the gear that magiccarpet listed, the vhf gives it a hiding if you log on before daylight tho. A 12v alternator is on my to do list but it's a long way down it.
Sam, I think the extra effiency of the mppt unit on small systems is debatable the savings could be used else where in the system to make it more efficient