# Solar deck instead of solar panels



## ulferlingsson (Jun 10, 2010)

Ever wanted to have more solar power than you could fit panels? On my 20' trailer sailer there is not room for more than maybe 20 W or so of solar panels, but I wanted to install 12 V A/C, which uses some 300 W or so, so to recharge the batteries for the next night I would need about the same effect from the solar panels. Solar cells give about 150 W per square meter, so I would need 2 square meters of pure cells, not counting the lost space between them. The only way to fit that was to put the cells directly on the deck (which has an area of 3.6 square meters). What I did was to build the panel directly on the white gelcoat, and cover the whole thing in clear gelcoat so one can walk on the deck again (the anti-skid pattern has yet to be added). See photos (the gennaker pole was added in the same rebuild of this 40 years old boat).

Other possible uses of this much power is a water desalinator, and an electric outboard. I'm already looking forward to for ever leaving the gas tank at home.


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## Donna_F (Nov 7, 2005)

Aren't the solar panels slippery?


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## ulferlingsson (Jun 10, 2010)

DRFerron said:


> Aren't the solar panels slippery?


As is, at present, it's just polished gelcoat. If they are too slippery I will add anti-skid pattern using a rubber product that is available on the market. One basically adds gelcoat in an anti-skid pattern over the deck.


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## sawingknots (Feb 24, 2005)

i'm doubtful,i'm going to build a custom bimini and also put panels there,an aircon would be nice but i'll settle for a decent fan


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## ulferlingsson (Jun 10, 2010)

sawingknots said:


> i'm doubtful,i'm going to build a custom bimini and also put panels there,an aircon would be nice but i'll settle for a decent fan


It's a HUGE amount of work involved in putting solar cells in the deck, so a ready-built panel mounted on some structure is a lot quicker to install, for sure.


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## rugosa (Aug 30, 2011)

Are any new boat builders offering solar deck?


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## Donna_F (Nov 7, 2005)

rugosa said:


> Are any new boat builders offering solar deck?


Yes.


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## ulferlingsson (Jun 10, 2010)

DRFerron said:


> Yes.


Actually it looks like they have put solar PANELS on the deck, rather than building panels out of solar CELLS directly on the deck... Using panels makes it easier, but adds weight.


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## sawingknots (Feb 24, 2005)

exactly,also your jib would create a lot of shade,a few days ago someone said that he replaced his lifelines with stainless tubing and mounted solar panels on that,hinged so they could be moved out of harms way in close quarters, that seems like a good alterative,i have a panel bracket mounted on my stern rail but still not enough


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## minnow1193 (Dec 20, 2011)

What is your boat? Coastal recreation- is it a Balboa?


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## cruisingdream (Feb 7, 2007)

With a dark blue (or black) solar cell deck, how hot is that going to be on bare feet?
or even how much heat transfer thru the deck ? (going to have to up the ac capacity)


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## mitiempo (Sep 19, 2008)

Shadows will cut the output down by a large amount.


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## davidpm (Oct 22, 2007)

ulferlingsson 

What panels did you use and how did you connect them?


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## -OvO- (Dec 31, 2011)

Also, I think the clear gelcoat (and textured gelcoat even more so) will cut the output more than you would expect. I say this because I talked to the architect of the local botanical gardens' big addition, and he explained that they had to use single-glazed glass instead of double-glazed because the extra layer of glazing would have meant that all the plants would starve to death in the winter. Who would have thought a layer of glass would substantially reduce insolation?

Not to say that it's a bad idea, you just have to overbuild the capacity. Pretty cool, imo.


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## hellosailor (Apr 11, 2006)

It will be very interesting to see how that holds up after some years of foot traffic and gear banging on deck, whether the panels develop microcracks and stress fractures or if they are durable enough to be installed that way, and keep working.


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## ulferlingsson (Jun 10, 2010)

I'll reply to all if I remember... It's an Ensenada 20, almost the same as Balboa. 

Shadows are a problem, to deal with that I have 2 x 47 cells, starboard and port are in parallel so if half is shadowed the other is still delivering full power. Also, if one cell is completely shadowed (as in someone sitting on it) it will act as a resistor and get very very hot. If 25% are shadowed no energy will be produced. To deal with that problem there are bypass diodes, 7 on each side, so that groups of cells can be completely bypassed. 

As for the cells being dark and getting hot for that reason, remember that they convert the light to electricity instead of heat. However, the minimum energy light they can use is near infra-red, and anything with more energy (such as all visible light) has excess energy that cannot be converted to electricity but turns into heat. Still, it gets a lot less hot than a non-solar panel surface of the same color.

By the way, the blue color is from blue pearl, the cells are really black when embedded.


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## ulferlingsson (Jun 10, 2010)

davidpm said:


> ulferlingsson
> 
> What panels did you use and how did you connect them?


6" x 6" solar cells bought on eBay. Get A grade, the others are inconsistent and lower power. If you buy a kit instructions come with it, I believe, but they are available on the net if you google. The cells can bend a little, enough to follow the normal bend of a deck. And use diodes, there are special solar cell diodes that are only a millimeter high and have minimal voltage drop. You also need a charging device, I got one good for 30 A that is automatic, can use from 36 to 72 cells and charge 12 V or 24 V.


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## -OvO- (Dec 31, 2011)

Love this. 

I think the clear gelcoat (and textured gelcoat even more so) may cut the output more than you would expect. I say this because I talked to the architect of the local botanical gardens' big addition, and he explained that they had to use single-glazed glass instead of double-glazed because the extra layer of glazing would have meant that all the plants would starve to death in the winter. Who would have thought a layer of glass would substantially reduce insolation?

Not to say that it's a bad idea, you just have to overbuild the capacity. Pretty cool, imo.


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## ulferlingsson (Jun 10, 2010)

-OvO- said:


> Love this.
> 
> I think the clear gelcoat (and textured gelcoat even more so) may cut the output more than you would expect. I say this because I talked to the architect of the local botanical gardens' big addition, and he explained that they had to use single-glazed glass instead of double-glazed because the extra layer of glazing would have meant that all the plants would starve to death in the winter. Who would have thought a layer of glass would substantially reduce insolation?
> 
> Not to say that it's a bad idea, you just have to overbuild the capacity. Pretty cool, imo.


I tested the change in output before I went ahead. It was not measurable with my voltmeter. The reason is that there is no air between the gelcoat and the solar cell. If there had been, it would have created specular reflection and a loss. However, the addition of too much blue pearl did lower the output a bit, I have yet to measure how much.


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## neverknow (Feb 2, 2011)

ulferlingsson said:


> I tested the change in output before I went ahead. It was not measurable with my voltmeter. The reason is that there is no air between the gelcoat and the solar cell. If there had been, it would have created specular reflection and a loss. However, the addition of too much blue pearl did lower the output a bit, I have yet to measure how much.


In time won't the gel coat become scuffed and scratched? You'd have to be careful of what cleaners you use. I'd also worry about someone dropping anything heavy on the decks.

Sure hope you report back in a few yrs as to how it works out.


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## davidpm (Oct 22, 2007)

ulferlingsson

Would this be a place to start learning:
LEARN TO BUILD YOUR OWN SOLAR CELLS PANELS DIY KIT | eBay

They are 2/2 not 6x6 but I'm thinking it might be enough to learn on.

I see many panels are 3 x 6 is that OK?
What about these?
108-3x6 solar cells manufacturing grade cells with wire kit and leadbox(A grade) | eBay

Do you have a link for the panels you used?
How do you choose.?

Are you using any encapsulant?
Did you sand the clear gellcoat?
If not how did you get it smooth?


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## Waymar83 (Jun 5, 2006)

Although this is an old thread, I am very curious and impressed as hell. Way to go! There are lots of compromises sure but its a great idea and needs to be tested under real conditions. Hope you are still around on Sailnet and will post an update on how its going. Its something I would sure consider on my Jeanneau 32 now that the boat will be on a mooring most days and I want to keep the fridge cold...


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## CorvetteGuy (Jun 4, 2011)

Love to see pics of the cabin interior and how the wires were hidden from veiw seems like there mite be a few to run.


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## svHyLyte (Nov 13, 2008)

The following "Deck Mounted Solar System" is easy to install and will definitely energize an entire race crew:










Solar panel Bikini's!!!


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## oldfurr (Dec 25, 2012)

Completely flexible plastic stick on solar cells with the same output as regular cells are now coming out of the lab & could be in production within a few years, should be a real game changer for solar power afloat as well as everywhere else. I'd imagine they would quickly be available/adaptable as ruggedized nonslip cut to fit rolls if they go into production. Looks like the weight would be HUGELY reduced compared to current set-ups. 
I can't link but a short article is on the site Extremetech "Stanford creates flexible, high-efficiency peel-and-stick solar cells"
By Sebastian Anthony on December 24, 2012 at 8:48 am


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## davidpm (Oct 22, 2007)

Stanford creates flexible, high-efficiency peel-and-stick solar cells | ExtremeTech


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## -OvO- (Dec 31, 2011)

Peel-and-Stick: Fabricating Thin Film Solar Cell on Universal Substrates : Scientific Reports : Nature Publishing Group

7.5% efficiency - that will need to improve, too.


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## Barquito (Dec 5, 2007)

I'm not an expert on solar, but, my guess is that for the square footage of solar cells, not a lot more power will be produced than an array mounted off the stern that doesn't have the problems with ventilation, thick overcoatings, and shading.


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## blutoyz (Oct 28, 2012)

I only have one thing to say about the solar deck....


Awesome!!


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## jobberone (Jun 24, 2012)

How fragile are the current cells being used? I like the cells atop a hard binimi (saying that without any experience) and was wondering if you can walk on them.


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## Arjen (Jan 18, 2012)

I have been thinking about doing this, but i didn´t for the following reasons:

-Good solar panels use special coated glass that reflect little light. Normal glass reflects a lot and cuts down on the efficiency. Gelcoat or whatever you put on there will undoubtetly be even worse than normal glas. If you make it antiskid, it will be downright terrible.

-Even little pieces of shaded cut down a lot on the energy output.

-Solar cells are very sensitive to crackling. I dont feel safe walking on them and maybe sometimes dropping pieces of stainless equipment or tools on them.

When i buy myself a campervan and i wont be dropping **** on the roof, walking on the roof and dont need anti skid, i do however intent to do this. Simply because cells are cheaper than panels and this way i dont need to build frames.

Sorry for not believing in it, it sure looks cool, and who knows, maybe im wrong


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## Arjen (Jan 18, 2012)

jobberone said:


> How fragile are the current cells being used? I like the cells atop a hard binimi (saying that without any experience) and was wondering if you can walk on them.


I would think that depends on the flexibility of your hard bimini and the amount of walking you do. They are pretty fragile, if they crackle, the power output goes down considerably. If it is a really sturdy bimini and you dont walk too often on them, maybe they can handle.


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## jobberone (Jun 24, 2012)

Arjen said:


> I would think that depends on the flexibility of your hard bimini and the amount of walking you do. They are pretty fragile, if they crackle, the power output goes down considerably. If it is a really sturdy bimini and you dont walk too often on them, maybe they can handle.


Is there a transparent substance sturdy enough to walk on that still will allow enough light to be transmitted thru it? I was thinking about placing something like a plexiglass housing over it. If so would you place it on the panels or raise it up enough to not touch it?


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## outbound (Dec 3, 2012)

thnk
1.solar technology continues to advance. If you have panels.easier to swap out.
2.cells break ( see above) if glassed in hard to swap out.
3.angle of incident light important determinent of output.
4. maintaining integrety of connections problematic.

Did energy calc.- if I get ~3y from panels they have paid for themselves at current fuel prices.

If to put on deck would use new flexible panels and deploy as needed.
Personally spec'd cored hard bimini. very rigid platfom for panels and out of harms way.


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## Mantus Anchors (Dec 13, 2011)

DRFerron said:


> Yes.


are you getting what you expected out of the array?
if you damage a pannel, how hard is it to replace?
Greg


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