Small Footprint Panels Needed, Recommendations?

[SDovey]

I am putting these on a Sailboat and room is limited. What are the best output small footprint panels? I would like to get to a minimum of 1kwh with the least amount of room and/or panels possible. I have 8 flooded batteries in 12V configuration.

 

[12VoltInstalls]

1kWh? Per day?
Or do you want 1000W of panels?

I’m assuming 1000W per day.

“Technically” monocrystalline panels have more output potential but these days the polycrystalline panels are essentially the same. So that’s a fine line I’d ignore.

In a good sun zone two 100W polycrystalline panels will make 1kWh/day
In a not good sun zone you might want 400 or even 600W of panels. 400 should fit on most small livaboards I’d think.

I currently am getting around or almost 2kWh / day from my 600W of panels even though I’m in Vermont. On sunny days anyway.

Best output is probably not the most relevant question, however. How much power do you need and where are you is the biggest questions.

 

[SDovey]

1kWh? Per day?
Or do you want 1000W of panels?

I’m assuming 1000W per day.

“Technically” monocrystalline panels have more output potential but these days the polycrystalline panels are essentially the same. So that’s a fine line I’d ignore.

In a good sun zone two 100W polycrystalline panels will make 1kWh/day
In a not good sun zone you might want 400 or even 600W of panels. 400 should fit on most small livaboards I’d think.

I currently am getting around or almost 2kWh / day from my 600W of panels even though I’m in Vermont. On sunny days anyway.

Best output is probably not the most relevant question, however. How much power do you need and where are you is the biggest questions.

I'd actually like 1000 watts of panels. I am in SW Florida at the moment. What is the smallest panels w/the most output?

 

[12VoltInstalls]

What is the smallest panels w/the most output?

All quality panels of a given size will be of similar output for their dimensions which will also be similar

monocrystalline panels have more output potential but these days the polycrystalline panels are essentially the same. So that’s a fine line I’d ignore.

Unless you’re doing something aerospace the question will have no practical difference for an answer. IMHO

 

[SDovey]

All quality panels of a given size will be of similar output for their dimensions which will also be similar

Unless you’re doing something aerospace the question will have no practical difference for an answer. IMHO

So, are there panels that are 12" x 12"? If so, what is the approximate wattage of such a panel? I am looking for recommendations from those of you who have been using solar and know what's good and what's not. I don't have the luxury of experience on my side, so I am coming to those of you who do have it. I'll look at what ever is recommended. I just don't know what is out there.

 

[SDovey]

I know Will Prowse recommends the "SanTan Solar T Series 250W" panels. However, they are out of stock at the moment. Are there any small panels that might fit in irregular spaces? Maybe I could fit more small panels around than just a few large ones. I really am just looking for recommendations from the community.

 

[Dzl]

I know Will Prowse recommends the "SanTan Solar T Series 250W" panels. However, they are out of stock at the moment. Are there any small panels that might fit in irregular spaces? Maybe I could fit more small panels around than just a few large ones. I really am just looking for recommendations from the community.

If he reccomends those panels, its probably from a cost efficiency perspective, not a space efficiency perspective. A residential panel rated for 250W is really quite low for the size, not an issue if you are not space constrained, but a waste of space if you are space constrained. Modern mid range and high end residential (60 cell) panels are in the ballpark of 300W-400W in the same footprint as the 250W Santan Panels, but they cost a lot more.

Based on the priorities you have outlined, you need to be looking for panels that have the highest watt rating per square foot/meter. All panels, have pretty standardized spec sheets and stickers on the back that include the tech specs. Get good at reading those, and then its just a matter of comparing the specs. Will and many people here are more focused on budget oriented/low cost/high value. For your use-case it sounds like you have identified space efficiency as your priority, this will lead you in a different direction than Will's recc's for the most part (and will also entail more $$).

There are two ways in which you can quickly compare panels in terms of space efficiency. Look at the module efficiency rating, a 22% efficient 100W panel and a 15% efficient 100W panel will both a produce (a theoretical) ~100W under the same conditions, but the 22% efficient panel will require a significantly smaller footprint, so you can fit more Watts in a smaller area. The second way is just look at rated Watts of the PV panel, and L*W (dimensions).

12" x 12" would be a pretty uncommon size, and require a lot of wiring if you are trying to get 1000W on your boat.

 

[Whinny]

These just showed up on Amazon up here, shingled glass panels. they claim a smaller footprint per watt-no idea if they meet specs.....

Solar Panels For Rv Trailer - 12v 110w monocrystalline Extra Compact Shingled Solar Panel Design, 12v Panneau Solaire 100w. Great for RVs, Campervans, Trailers, Cottage, Shed or Beach. Perfect for all Off-Grid Projects. (1, 110 Watts) : Amazon.ca: Pa

Solar Panels For Rv Trailer - 12v 110w monocrystalline Extra Compact Shingled Solar Panel Design, 12v Panneau Solaire 100w. Great for RVs, Campervans, Trailers, Cottage, Shed or Beach. Perfect for all Off-Grid Projects. (1, 110 Watts) : Amazon.ca: Patio, Lawn & Garden

www.amazon.ca

 

[SDovey]

If he reccomends those panels, its probably from a cost efficiency perspective, not a space efficiency perspective. You need to be looking for panels that have the highest watt rating per square foot/meter. All panels, have pretty standardized spec sheets and stickers on the back that include the tech specs. Get good at reading those, and then its just a matter of comparing the specs. Will and many people here are more focused on budget oriented/low cost/high value. For your use-case it sounds like you have identified space efficiency as your priority, this will lead you in a different direction than Will's recc's for the most part (and will also entail more $$).

There are two ways in which you can quickly compare panels in terms of space efficiency. Look at the module efficiency rating, a 22% efficient 100W panel and a 15% efficient 100W panel will both a produce (a theoretical) ~100W under the same conditions, but the 22% efficient panel will require a significantly smaller footprint, so you can fit more Watts in a smaller area. The second way is just look at rated Watts of the PV panel, and L*W (dimensions).

12" x 12" would be a pretty uncommon size, and require a lot of wiring if you are trying to get 1000W on your boat.

Understood, thanks. The 12" x 12" was an exageration. I was just trying to spark out of the box thinking.

 

[SDovey]

These just showed up on Amazon up here, shingled glass panels. they claim a smaller footprint per watt-no idea if they meet specs.....

Solar Panels For Rv Trailer - 12v 110w monocrystalline Extra Compact Shingled Solar Panel Design, 12v Panneau Solaire 100w. Great for RVs, Campervans, Trailers, Cottage, Shed or Beach. Perfect for all Off-Grid Projects. (1, 110 Watts) : Amazon.ca: Pa

Solar Panels For Rv Trailer - 12v 110w monocrystalline Extra Compact Shingled Solar Panel Design, 12v Panneau Solaire 100w. Great for RVs, Campervans, Trailers, Cottage, Shed or Beach. Perfect for all Off-Grid Projects. (1, 110 Watts) : Amazon.ca: Patio, Lawn & Garden

www.amazon.ca

taking a look, thanks

 

[SDovey]

I found these also, any input on these?

DOKIO 150 Watt 12 Volt Solar Panel Durable HIGH Efficiency Module for RV, Boat, Home Off Grid System : Amazon.ca: Patio, Lawn & Garden

DOKIO 150 Watt 12 Volt Solar Panel Durable HIGH Efficiency Module for RV, Boat, Home Off Grid System : Amazon.ca: Patio, Lawn & Garden

www.amazon.ca

 

[SDovey]

Can panels be mixed and matched? Can you combine smaller panels and larger panels? Can some be Poly and some be Mono?

 

[SDovey]

These just showed up on Amazon up here, shingled glass panels. they claim a smaller footprint per watt-no idea if they meet specs.....

Solar Panels For Rv Trailer - 12v 110w monocrystalline Extra Compact Shingled Solar Panel Design, 12v Panneau Solaire 100w. Great for RVs, Campervans, Trailers, Cottage, Shed or Beach. Perfect for all Off-Grid Projects. (1, 110 Watts) : Amazon.ca: Pa

Solar Panels For Rv Trailer - 12v 110w monocrystalline Extra Compact Shingled Solar Panel Design, 12v Panneau Solaire 100w. Great for RVs, Campervans, Trailers, Cottage, Shed or Beach. Perfect for all Off-Grid Projects. (1, 110 Watts) : Amazon.ca: Patio, Lawn & Garden

www.amazon.ca

Does anyone have any familiararilty with these?

 

[NPhil]

I'm using the NewPowa 100W panels, which were advertised as compact, and they are a little smaller than the average in their class, which is good, because they fit on the roof of my minivan, but, I'm not sure they are entirely comparable to other 100W panels which are a little larger (I'm new at solar, those were my first large panels).

https://www.amazon.com/Newpowa-Monocrystalline-Efficiency-Module-Marine/dp/B01LY02BOA?th=1

They go a little over 80W here in San Jose. I think I've seen 87.5 watts out of them, once. That might be typical for the class, though. I do have one pair of 100W panels which are 1/2 the weight, though larger, evidently because they don't have glass, they put a semi-flexible panel in a frame. On a good day I can get maybe 75W out of those.

I'm pretty sure, from what I have read, that the Sunpower cells will do better, in a little less space, but they cost twice as much, which is a problem for me, although not for everyone. Here is a panel which uses them:

Amazon.ca

But who knows, that shingled thing might be better still. I'm skeptical, but, if I had the budget, in money and time, for it, I might try them just to see.

 

[Dzl]

I'm pretty sure, from what I have read, that the Sunpower cells will do better, in a little less space, but they cost twice as much

That is what I've heard also, Sunpower cells I think are some of the more efficient cells. In terms of Modules (panels), Sunpower, REC, and a handful of other reputable brands have some pretty efficient offerings, but for the most part you see the highest panel efficiencies in the 60 cell, 72 cell, and more exotic large panels.

If that Renogy panel you linked to is really 22% efficient, that is good efficiency for the 100W size! (quite expensive though)

But who knows, that shingled thing might be better still. I'm skeptical, but, if I had the budget, in money and time, for it, I might try them just to see.

I think as a general rule, being skeptical to any new product or 'new tech' type thing sold on amazon/ebay/aliexpress in the solar market is a good baseline assumption. New things come about, improvements are made, etc, but its 10 to 1 or 100 to 1 marketing bs to actual advancements, and where actual advancements do occur, its unlikely amazon off-brands will be where they are first debuted. Not saying anything about this particular product in general, I know nothing about it, just agreeing with/reflecting on your position of skepticism in general.

 

[12VoltInstalls]

What is the available space? Do you want some permanent cockpit cover?

You can figure about 13.75W/sq.ft. for commodity small panels. The best low priced commodity panels seem to be WindyNation or Rich Solar. Windy panels are 26”x40”, Rich says 39.6”x26.6”

So you can see the sizing is somewhat predictable, and 100W is not that large. The odd form factor lets you arrange them somewhere convenient

Can panels be mixed and matched? Can you combine smaller panels and larger panels? Can some be Poly and some be Mono?

1- yes and no. Yes if specs are close. I have half windy and half rich installed at the moment
2- no, if they don’t match you limit the output to the lowest max power in a string. So it doesn’t make sense.
3- sure, but again there’s losses you need to pay attention to.

 

[svfalkor]

@SDovey ,
I would try to go the other way round:

1. determine where you will put the panels. Since there is limited surface area and always shade on a sail boat you probably have to put them into different places. E.g I have panels on my davids, bimini, dodger and hand rail around cock pit.
2. Once you have found where to put them you can determine what kind of panels fit there. Most likely it won't be the same everywhere. I have connected each set of panels with its own charge controller to make them independent of each other. Adds redundancy.
Example: On my davids I have one big house panel 2000mm x 100mm, on the bimini I have 2 100W panels.

Cheers Patrick

 

[Dzl]

I second @svfalkor reccomendation to use multiple small charge controllers. One for every 1 or 2 panels, or at a minimum 1 for starboard, 1 for port. There are other ways to optimize an array for partial shade, but this is the simplest and most effective afaik. Essentially its similar to the concept of microinverters for a residential system, each panel is indepenedent of the others.

 

[NPhil]

I am putting these on a Sailboat and room is limited. What are the best output small footprint panels? I would like to get to a minimum of 1kwh with the least amount of room and/or panels possible. I have 8 flooded batteries in 12V configuration.

On my minivan, I have a similar situation. I'm using, as I mentioned above, the https://www.amazon.com/Newpowa-Monocrystalline-Efficiency-Module-Marine/dp/B01LY02BOA?th=1, because they fit, and because I can't afford the high end panels with somewhat better output per square inch. But I'm going to need 1200 (nominal) watts, I estimated, and am verifying, with daily testing using 400 (nominal) watts, which is much larger than a minivan roof. My plan to resolve that is to make a stack of three layers of panels, with mounts which allow me to expand them when practical. My mount design for that isn't final (it's complicated), but slides are a possibility I've looked at, there are a couple of YouTube videos on that.

It occurred to me that my plan for using the array (stacked and secured, nominally 400W, while driving, unstacked and nominally 1200W while parked) might be feasible on a boat, even a sailboat.

I should mention that my rough estimate of the final weight for panels, cable, and mounts is only just under the maximum recommended dynamic roof load for the vehicle, which isn't ideal, but I guess my best option. My plan is to compensate by locating heavy things which go in the van (batteries, water, etc., low, and if I go to off-road tires, changing to wheels which have a wider track. I suppose, in a sailboat, you might, if you have a stack of solar panels on slides somewhat centrally located, design a servo system which automatically moved that weight side to side, to counter lean.

 

[ianganderton]

I think things are getting on the right track here

I’m my experience efficiency of panel is less important that efficiency of space used. Finding the right panels to Tetris into your available space is going to be key

Secondly making sure the panels you have are running as optimally as possible. Shade is a huge issue on boats. Having lots of small panels in parallel with several arrays on separate mppt controllers is definitely worth considering.

Big panels will probably look more efficient based on watt by area but there will be lots of ways they will be problematic.
1- they can be fragile in mobile applications
2- they will be dramatically affected by shading
3- they are prone to water pooling on them when flat (typical in mobile applications) which causes dirt build up and resulting inefficiencies

Be wary of flexible panels. They can seem a good solution for mobile applications but they don’t seem to like being permanently mounted and degrade quickly

But maybe having a set of flexible panels that can be stored when the boat is out and about but mounted on deck facing the sun when in a marina of anchored would be a good option