Best Solar Panels for Airstreams

[ROBERT CROSS]

Why is my roof painted white?
Would a black, no air gap roof cause enough heat expansion to loosen rivets, will the self stick panels stay stuck when hot at 65mph?
Replacement time...easy removal with no hassle.
Time will tell.

POI...we use two 180W portable.

Bob
🇺🇸

[Humboldt Air]

Originally Posted by ROBERT CROSS

Why is my roof painted white?

Would a black, no air gap roof cause enough heat expansion to loosen rivets, will the self stick panels stay stuck when hot at 65mph?

Replacement time...easy removal with no hassle.

Time will tell.



POI...we use two 180W portable.



Bob

[emoji631]

I think it is prudent to paint the roof white in some circumstances. My roof has never been white and the shiny silver has always gotten hot enough to fry an egg on. The black panels may be hotter than the original surface but not by very much.

My airgap has always been the insulation between skins and works relatively well considering its only 1.5" gap. There is no noticable heat difference between the previous 15 years of use and the last couple years with the solar installed. I think that this does need a bit more tangible investigation and a temp gun should do the trick. I will post my findings in a later post.

Mainly I think this solution works so well for our family because of the way we use our airstream. We don't sit inside on hot days at campgrounds with full hookups and run AC. We are outside all day and if for some reason we want to be inside we are running our fantastic fans and don't have any heat build up. In the cooler times it could possibly be a boon, but again we haven't noticed a notable difference in the inside temp.

As for rivets popping, we haven't had an exterior rivets pop in the last 20 years of ownership. I don't consider this to be relevant. As to the solar panels becoming unstuck, we have traveled a few thousand miles in high heat at speed and had no problems. Considering the entire panel is backed with adhesive and they had been tested to over 100 mph, wind loads by engineers, I also don't consider this to be relevant.

What I really would like is to hear from any other person who has installed these panels on their airstreams and see what they have to say. I used to run around the camp site all day trying to collect sunshine with a 70 watt panel. Now I don't have to worry about that any more and I have been able to install these panels by myself in around 2 hours.

The entire reason for the post is to help others who might be in a place where they want to maintain the look of their Airstream, "more for the VIntage crowd" while providing Very High performance in electrical capacity improvments without breaking the bank. CGIS has solved all of our requirements for solar.

[martin300662]

Originally Posted by uncle_bob

Hi

If they *have* wired all the cells in parallel, then the panels will only put out < 1V in full sun. That would take a *very* unusual controller ....

The only way to get things to work and put out the ~20V the normal controller is looking for is to have cells in series.

Bob

Glad to hear you have an opinion to share as usual Bob

[uncle_bob]

Originally Posted by martin300662

Glad to hear you have an opinion to share as usual Bob

Hi

Ok, so see:

https://electricalgang.com/solar-cel...n-and-working/

https://www.solar-facts.com/panels/p...nstruction.php

https://en.wikipedia.org/wiki/Solar_cell

https://www.cleanenergyreviews.info/...modules-review

https://www.electrical4u.com/solar-cell/

https://global.kyocera.com/prdct/sol...olar/cell.html

(and there are *lots* more).

If basic electric circuits are a concern, there's information on them out there as well.

Bob

[martin300662]

.....to try and put the question of impact of absorption on both adhesive qualities of the panels and heat transfer to the trailer/motorhome, to bed. I have been working with one of the manufacturers of the panels and they are happy to expand current trials they have on-going with Sika (who design and supply their adhesives).

However to do so we would need to generate some test pieces. The OP's situation of bare aluminium is easy to replicate, I am suggesting they also test elastomeric polymer paint (such as Henry HE687046 Environwhite) and also Bus-Kote #2150. Any other suggestions?

FYI they already had their own program investigating similar impacts, as they have a white reflective backed version of the CiGS ongoing to try and maximize the available energy. So a little participation now could really end up with a 'best solar panel for Airstreams' going forward

[martin300662]

Originally Posted by uncle_bob

Hi

Ok, so see:

https://electricalgang.com/solar-cel...n-and-working/

https://www.solar-facts.com/panels/p...nstruction.php

https://en.wikipedia.org/wiki/Solar_cell

https://www.cleanenergyreviews.info/...modules-review

https://www.electrical4u.com/solar-cell/

https://global.kyocera.com/prdct/sol...olar/cell.html

(and there are *lots* more).

If basic electric circuits are a concern, there's information on them out there as well.

Bob

So you know the size of cells being paralleled?

Great example of 'I know the answer', now what is the question!

[uncle_bob]

Originally Posted by martin300662

So you know the size of cells being paralleled?

Great example of 'I know the answer', now what is the question!

Hi

It's basic semiconductor physics (as noted in those references) ... or did you not happen to take that course when you got your engineering degree?

Bob

[martin300662]

Originally Posted by uncle_bob

Hi

It's basic semiconductor physics (as noted in those references) ... or did you not happen to take that course when you got your engineering degree?

Bob

The difference is, I am not claiming to know better than the manufacturer of the panel Bob.

Nothing I have written is my assumption, I prefer to listen to the experts rather than claim to be one.

[ROBERT CROSS]

Not fair... I'd be in the woodshed by now. 🥴

Bob
🇺🇸

[uncle_bob]

Originally Posted by martin300662

The difference is, I am not claiming to know better than the manufacturer of the panel Bob.

Nothing I have written is my assumption, I prefer to listen to the experts rather than claim to be one.

Hi

*Everything* you have said is your own totally unsupported assumption.. You haven't backed anything up anything at all.

Again, solar cells as individual units don't put out over a volt. That's just the way it works. If you can find an "expert" who has a individual silicon cell does not conform to this, post a link.

Bob

[martin300662]

Originally Posted by uncle_bob

Hi

*Everything* you have said is your own totally unsupported assumption.. You haven't backed anything up anything at all.

Again, solar cells as individual units don't put out over a volt. That's just the way it works. If you can find an "expert" who has a individual silicon cell does not conform to this, post a link.

Bob

Who mentioned silicon cells?

The CiGS panels are thin layer coatings on flexible substrates and each cell is an assembly of areas of the coated thin layer substrate. Each individual cell is an assembly, the assembles are then connected in parallel.

Would a copy of the email from the companies technical department that describe this help, or do you prefer the 'scientific rigour' of Wikipedia?

https://en.wikipedia.org/wiki/Copper...de_solar_cells

As I said yesterday, I am not an expert, but if the experts (the manufacturer of the panels) tells me something, I tend to believe that over comments on an internet discussion forum - others may disagree, I have no issue with that.

[uncle_bob]

Originally Posted by martin300662

Who mentioned silicon cells?

The CiGS panels are thin layer coatings on flexible substrates and each cell is an assembly of areas of the coated thin layer substrate. Each individual cell is an assembly, the assembles are then connected in parallel.

Would a copy of the email from the companies technical department that describe this help, or do you prefer the 'scientific rigour' of Wikipedia?

https://en.wikipedia.org/wiki/Copper...de_solar_cells

As I said yesterday, I am not an expert, but if the experts (the manufacturer of the panels) tells me something, I tend to believe that over comments on an internet discussion forum - others may disagree, I have no issue with that.

Hi

Ok, CIGS cells are *worse* in this respect than silicon.

(the band gap data actually is in the article you quote). It's more clearly shown here:

https://www.researchgate.net/figure/...fig2_283175404

If you want to go for a deeper dive there's this:

https://www.google.com/url?sa=t&rct=...Eo9_csomi03zsS

Bob

[Humboldt Air]

I don't even really understand the argument here. The data is clear that CIGS panels are less efficient than silica based construction, (at this current moment). But that isn't the point. The form factor of these panels is Great!!! The weight savings and the ease of use is wonderful! I have a 24' tradewind and was able to have 490 watts on my roof without much ability to see the panels, or need help with install. I could have installed more panels but I don't need to make any more power.

My real world use and testing has illuminated the wonderful up side to these flexable light weight panels. IMHO thin film solar is the future of the industry. I think that someone who has more resources to test the products should grab a panel and compare the results.

Bob, you seem like the person for the job. You seem well versed in the science community and are interested. I wouldn't know where to start an accurate comparison. I do know the pro's and con's but it seems that some people just are not ready to try these out and I really don't understand the hesitancy.

So many people comment on this thread without much knowledge and really it dosen't take much research to find the data. It seems people need some youtuber to be charming and charasmatic and show these panels to others......this again isn't my shtick.

I attached some real world data here. Our most recent trip we were parked in a valley without trees directly over head but well surounded. We had some cloudy days and very smokey days (the fire season is well under way). I tried to run our systems recklessly without any consideration for conservation. I have a 200 Ah lifepo4 battery and I never fell below 70% SOC. BTW I use a BMS with a build in shunt.

On the last day of our trip we headed back home with our absorbtion fridge on the whole way like normal. This time we were stopped in traffic waiting for road construction to clear along with a bad accident, (Folks Please DRIVE SAFE). We were stopped in the redwoods with little access to sun for about 2 hours. We still pulled into our driveway with around 70% in the battery, that is why the charging spike is higher on that day.

I think if I just looked into the numbers for solar conversion rates and not other factors I would not want to look into thin film solar now. But the real world environment is surpirsing. These panels come in a variety of sizes and can be made in different colors. I don't know what others experience but our set up starts producing power before direct sunlight hits the panels in the morning.

Any way, lets stay away from personal attacks and get back on track with tangible evidence.

[TouringDan]

I agree with you. I never considered flexible panels due to what I had read on the internet and am quite happy with the 400 watts of rigid panels I installed on my bed cap. Your flexible panels are clearly working well for you as your batteries are getting fully charged each day. Thanks for the education on what you are doing that works well for you and could work well for others.

Dan

[KellySLC49]

I know this is a bit of an older post, but we're looking at using the same panels on our '52 Silver Streak Clipper. We're thinking of using MiraSole's 50W panels, since their smaller size will allow us to run them east-west and get more watts on the roof. I've seen videos where they install these over that corrugated white plastic-cardboard stuff, but thought I'd ask if the additional 5-degree increase in inside temps has been noticeable. The interior of our trailer will be shiny aluminum as well and it still gets hot during our 100 degree days here (Utah), despite 1.5" of blue foam insulation and Armaflex pipe insulation on the ribs. BTW, we're doing a series-parallel install in a 3x2 configuration for a total of 6 of the smaller, 40x14, 50W panels. We'll be installing a mini-split system and will have another 400W-500W on the ground with a second MPPT Victron controller. 12v-only Isotherm fridge too. How have you found your array capacity? Does it still keep up with your needs?

Thanks!

[KellySLC49]

Well, I tried to edit after noticing newer messages, but I guess you're limited to edits within 30 mins. I just read the OP's update (and realized there have been more recent posts). I'd still like to know how you have found your total watt capacity to be and if it's still enough.

[Humboldt Air]

Originally Posted by KellySLC49

I know this is a bit of an older post, but we're looking at using the same panels on our '52 Silver Streak Clipper. We're thinking of using MiraSole's 50W panels, since their smaller size will allow us to run them east-west and get more watts on the roof. I've seen videos where they install these over that corrugated white plastic-cardboard stuff, but thought I'd ask if the additional 5-degree increase in inside temps has been noticeable. The interior of our trailer will be shiny aluminum as well and it still gets hot during our 100 degree days here (Utah), despite 1.5" of blue foam insulation and Armaflex pipe insulation on the ribs. BTW, we're doing a series-parallel install in a 3x2 configuration for a total of 6 of the smaller, 40x14, 50W panels. We'll be installing a mini-split system and will have another 400W-500W on the ground with a second MPPT Victron controller. 12v-only Isotherm fridge too. How have you found your array capacity? Does it still keep up with your needs?



Thanks!

What a wonderful, beautiful work of rolling art.....I was like.....jelly . Just a few things to give some thought to. Where will the combiner box go and wire management.

I originally was going to run my panels east west also, but when my wife suggested that we run them north south, it really makes more sense in a few ways. You can separate the arrays in a more productive way and you can make a singlular wire chase along the top to have a nice clean installation.

The heat difference hasn't been noticable to us but we don't run any AC. I dont know if the temp will make any difference in your airstream. Maybe you can do a test. Painter tape on some black contractor bags and see if the inside temps become different?

To date my power needs have been met in every situation I have been in, but I think two things.

1. Oversize all wires to meet future demand.
2. Install as much solar as you feel looks good on your airstream.

Lovely project!!!!!!!!!

[TouringDan]

Humboldt Air- I totally agree. You can never install too much solar.

One of our Airstreams is a 95 34’. We may be installing 1,800 watts of solar.

Dan

[Humboldt Air]

Touring Dan,

I would love to see the 34' with all that solar, that sounds really fun. I also like your creative solution with the panels on the TV. I haven't see anyone do that before and it seems very creative! After using it how does it work out for you?

[TouringDan]

HA- I have a thread in the solar section last dated 3/17/21 titled “400 watts on my truck bed cap” with the installation details. I thought about installing rigid panels on the Tradewind but just couldn’t ruin the looks of a beautiful Airstream. It was really the motivation to come up with a plan to install rigid panels on my truck bed. The installation was really quite simple- bolt the 4 panels together, install brackets on the panels and use very high bond tape to secure the brackets to the bed cap. The hardest part was securing the wires penetrating the bed cap to the ceiling of the bed cap.

The solar panels have worked quite well over about 20,000 miles in the last two years. There have been absolutely no problems. Well, there is one problem though. I generally carry a kayak on top when we travel. This typically shades about 300 watts of the solar panel which means I get the performance of a 100 watt panel. Oh well, when we get to the destination I just unload the kayak if we need more than 100 watts of solar to charge the batteries.

So glad that you found some solar panels that seem to work well on vintage Airatreams.

Dan