Flexible Solar Panel mounted directly on Sunbrella

[hellosailor]

I've used some panels that are mounted onto a thin stainless backing sheet. It is "flexible" in the sense that it can be bent to any simple (not compound) curve. But I have to say that the stainless gets hot enough to burn flesh when it has been in the sunlight all day, and I can't think that it good against fabric. It would have to age the fabric, or the waterproofing and UV coating that is in Sunbrella, as well. A piece of closed call phone, or foamcore, or something else in between the two would seem to be the more cautious way to go. Something like hollow core ("corrugated") PVC board might be a good idea as it would also allow some cooling air to flow under the panel, which should also increase efficiency.

[Maine Sail]

Originally Posted by Paul L

125w Solibian US$856
2 158watt $268 plus $95 shipping = $181 each
So for roughly equivalent wattage (250 vs 314) it is $1,712 vs $363. That's a big difference.

I really like the Solibians as a concept. I just can't justify the 4.7x cost. The multiplier is less if you have to add a bunch to mount the hard panels vs a possibly simpler, less costly mount for the Solbians.

Seems like you are not comparing a quality rigid panel to a Solbian or apples to apples.. Yes there are plenty of el-cheapo Chinese panels that have flooded the market but compare a brand like Kyocera to Solbian and the price difference is much less. A single Kyocera 140W panel is about $280.00 + shipping...

Were the real equalizer comes in is when you need to beef up a bimini to hold a rigid panel and then where do those rigid panels go in a blow when you have to remove them? The Solbian's simply Velcro off and get stowed under a berth cushion and you'll never know they are there.


By the time a customer is done paying me to do an install the cost difference between Solbian and a rigid installation that requires SS work, gobs of fittings and the shop time to fabricate it all the Solbian price premium is pretty small...



Can't even tell its there....



Not for everyone but right now the vast majority of my customers are choosing Solbian for weight, aesthetics and stowability...

This is a real selling point for many owners... No 40 pound sharp edged panel flying about the cabin in 15 foot seas....

[tartansail]

We have 2X125 watt Solbian panels zippered onto our bimini. They have performed extremely well, but, as noted, they aren't cheap. The guy who did the zippers added a sacrificial strip of cloth along the edges of the panel. While the edges aren't extremely sharp, he thought they were sharp enough to shorten the lifespan of the bimini Sunbrella. It's cheap insurance and an invisible modification.

[Paul L]

Originally Posted by Maine Sail

Seems like you are not comparing a quality rigid panel to a Solbian or apples to apples.. Yes there are plenty of el-cheapo Chinese panels that have flooded the market but compare a brand like Kyocera to Solbian and the price difference is much less. A single Kyocera 140W panel is about $280.00 + shipping...

Were the real equalizer comes in is when you need to beef up a bimini to hold a rigid panel and then where do those rigid panels go in a blow when you have to remove them? The Solbian's simply Velcro off and get stowed under a berth cushion and you'll never know they are there.


By the time a customer is done paying me to do an install the cost difference between Solbian and a rigid installation that requires SS work, gobs of fittings and the shop time to fabricate it all the Solbian price premium is pretty small...



Can't even tell its there....



Not for everyone but right now the vast majority of my customers are choosing Solbian for weight, aesthetics and stowability...

This is a real selling point for many owners... No 40 pound sharp edged panel flying about the cabin in 15 foot seas....

Yea, if you are paying someone else to do the install and have to do anything significant to the mounts, then the cost of the panels is in the noise compared to the labor and mounting brackets.
The numbers I gave were for panels that I'm comparing for myself. Even if I go with 140 Kyocera I'm comparing it is $560 plus $53 shipping = $613 vs $1,712 (plus shipping) or a 2.8 multiplier. Give me a discount so I can get it down to 2x multiplier and I'd be in the market.
I'm not convinced that the Kyoceras are that much better than the other cheaper brands - maybe -- just not convinced that they should demand a 2x multiplier over the overstocked panels.

[Normanby]

Re price, the reduced weight and foldability should make a difference in freight costs (I'm Down Under).

Is there a distributor in Oz?
We Aussies often get royally screwed on freight costs from US and EU.

[neelie]

A Question for the gurus....

I am aware that it is not recommended to mount the Solbian panels over the bows of the bimini. This pretty much implies that one can only mount them athwartship in between the bows.

This is less than ideal for me. I would like to mount them in the fore and aft direction and hence across the bows of the bimini.

So, how about my mounting the panels with something like 3/4 inch lightweight closed cell foam panels as backing between the solar panels and the bimini to remove hard spots?

I envision a pillow like affair with the Solbian panels velcro'd to the pillows which in turn are either zippered to or velcro'd to the bimini fabric.

Will this work?

If not, then how about the addition of a couple of fibreglass battens under the foam ?

[tartansail]

Originally Posted by neelie

A Question for the gurus....

I am aware that it is not recommended to mount the Solbian panels over the bows of the bimini. This pretty much implies that one can only mount them athwartship in between the bows.

This is less than ideal for me. I would like to mount them in the fore and aft direction and hence across the bows of the bimini.

So, how about my mounting the panels with something like 3/4 inch lightweight closed cell foam panels as backing between the solar panels and the bimini to remove hard spots?

I envision a pillow like affair with the Solbian panels velcro'd to the pillows which in turn are either zippered to or velcro'd to the bimini fabric.

Will this work?

If not, then how about the addition of a couple of fibreglass battens under the foam ?

My understanding is that you don't want sharp bends, but that fore and aft is fine if your bimini is reasonably flat. The attached photo shows our fore and aft setup. Depending on your choice of foam, your approach could also protect the bimini sunbrella from the panel edge.

[Maine Sail]

Originally Posted by neelie

A Question for the gurus....

I am aware that it is not recommended to mount the Solbian panels over the bows of the bimini. This pretty much implies that one can only mount them athwartship in between the bows.

This is less than ideal for me. I would like to mount them in the fore and aft direction and hence across the bows of the bimini.

So, how about my mounting the panels with something like 3/4 inch lightweight closed cell foam panels as backing between the solar panels and the bimini to remove hard spots?

I envision a pillow like affair with the Solbian panels velcro'd to the pillows which in turn are either zippered to or velcro'd to the bimini fabric.

Will this work?

If not, then how about the addition of a couple of fibreglass battens under the foam ?

It is not recommended because like anything allowed people push the acceptable limits, ruin stuff and then ask the manufacturer to pay for it. Solbian finally had to put their foot down on installations over bows..

The truth is if you use common sense, have a nice taught bimini, not a sloppy jalopy, and the bows are not going to bend the panel more than about 5-10%, in one direction only, you will likely be okay.

I would suggest a very careful layout in which the bend/bow center is between two cells, not in the middle of a cell row. These panels do not like to flex in two directions but a slight bend in one direction is okay if done carefully. These are semi-flexible monocrystalline panels, not flexible roll up amorphous panels and people often confuse how much they can bend...

[neelie]

Tartansail - I don't mean to be critical but the photo makes your bimini canvas look a little loose.. does it flutter in gusty conditions?

Mainsail - Thanks for that. I was thinking of the 4 x 125W panels which are 54 inches long. So avoiding a bow will be easier said than done.

I was thinking that with some sort of foam backing to provide a bit of rigidity and support together with a couple of 55 inch battens running lengthwise under the foam that will stop flexing and bending over a bow that I should be ok.

I was also thinking that the foam would prevent fluttering - which I assume to be deadly to these panels.

---

ps.. I just noticed that emarineinc.com have a 3/8" honeycomb backer for the 125W panels for sale - this may be a better idea than my closed cell foam idea.. hmmmm..

[bgallinger]

I intend to install 2 - 80 watt Solbian panels on the aft section of my bimini as it is clear of any shading from the boom. So far, the consensus in this thread shows the Solbian panels to be lightweight, easily removed and stored, expensive, and some varying concerns about sharp edges and heat transferred to Sunbrella fabric.
Can anyone comment on the ability of 2 - 80 watt Solbian panels keeping up with typical power demands i.e. fridge, freezer, fresh water pump, etc.?

[Pete7]

Originally Posted by bgallinger

Can anyone comment on the ability of 2 - 80 watt Solbian panels keeping up with typical power demands i.e. fridge, freezer, fresh water pump, etc.?

Without knowing your power usage that is impossible to answer. However, during the summer months in the UK (50.N) with good sun we can stay at anchor for 5 days running fridge, lights, laptops etc quite happily with 125w of solar which will peak at 7.5ah mid day charging 2 x 110AH batteries.

Given your location isn't in the tropics, you have long daylight hours in the summer and a similar sized yacht, without the freezer you should be okay. You will need some form of battery monitor though. The cheapest NASA BM1, will do, other types have a few more bells and whistles which are not essential, however, its insurance to ensure you don't run down the batteries below 50% (12.2V) and shorten their life excessively.

The freezer may be the sticking point on your set up, ours is the diesel fired heating, we can do a couple of nights then need to charge by engine or mains.

Pete

[bgallinger]

Thanks Pete! I do have the BM-1 battery monitor already. The boat came with a factory installed fridge and I intend to install an Engel freezer, hence the idea of 2 - 80 watt panels which should hopefully deliver 10 amps peak to cover typical usage.

[barnakiel]

One can add velcro mounted battens to the sunbrella roof and then place the panels over the battens. There will be good ventilation and no chafe.

In fact. If lock-on-lock (e.g. dual-lock 3M) velcro is used this can be the only attachment point. However this will work only over very tight stretched roofs.

b.

[hellosailor]

bg-
" hence the idea of 2 - 80 watt panels which should hopefully deliver 10 amps peak to cover typical usage."
Are you confusing Amps with AmpHours? Your icebox may draw 10 amps "constantly" or it may draw 10 amps during 20 minutes out of every hour. If you multiply the amps times the amount of time they are drawn, you get amp-hours, or amp-minutes if you prefer.
The two panels will give you about 160 watts, and depending on their characteristics and the type of charge controller you use, that may translate into 10 amps, yes. During the three or four hours right around noon. So you may get 50 amp-hours form the panels during the entire course of a day, while your icebox is drawing amps 24 hours per day.

Maine-
Those Solbian panels look sweet, but are they warranteed for marine use? And do they have a track record? I ask because a couple of months ago I was reading a piece in one of the leading financial publications about the solar industry, and they claim that there's a dirty little secret involving a very high (15-20%) failure rate, even in some brand name panels that are not made in China. Apparently a lot of suppliers have been cheating the manufacturers as demand was ramping up and prices pressured to go down.

[nautical62]

I used flexible solar panes mounted on the bimini on my first boat. No problems mold or anything growing under them. Lots of problems in windy conditions. The bimini was solid, but still wind getting between the panels and the fabric was an issue.

I end up keeping them up only under fair weather conditions or at anchor and stored them under my settee seat otherwise.

For me, the power the produced made a difference - when I could use them all day.