solar ready ???

[Milo1952]

Hi!

I have a 2017 international Signature and would like to add solar.
It is supposedly solar ready, whatever that means.
Can I put 2 100w panels on the roof and add a charge controller
and be good to go ? Will the wiring support 2 100w solar panels?
I simply want to be able to charge the batteries when parked.
Was thinking about going with Zamp suitcase but don't want to
be tied down to the trailer for fear of theft.
Any info would be very helpful in my deciding what to do next.

[AirMiles]

Yes, read my "Solar Show & Tell" thread that explains how I put 400W on the roof using the factory prewire on my 2017. There are many pictures of how to and performance results. http://www.airforums.com/forums/f448...ll-181608.html

With only 200W, you would run the wires from each 100W solar panel directly to the Zamp rooftop box - a parallel design. With 400 or 600 Watts, you would need a series/parallel design to use the factory prewire with pairs of 100W panels in each series connected to the Zamp rooftop box.

I really like the Victron controller and its Bluetooth interface. I bought my whole system from AM Solar: https://amsolar.com/ There are many how-to videos to help you there and they are a great resource to help if you buy your equipment from AM Solar: https://amsolar.com/rv-solar/support

AirForums is also a great resource with many helpful Airstreamers that have done this installation that will help you along the way. Its really fairly easy to install solar on a 2017+ Airstream with the rooftop Zamp box and solar prewire.

[QC TORPEDO]

I am having the dealer install solar panels on the roof of my '17 FC. It is pre-wired. Where will the controller end up?

[hhendrix]

I had 300 watts of panel on top of mine 2009 Airstream. It had the Zamp controller and display. They worked fine although I thought the display could have better information.

Two problems; reduced performance when parked in the shade which was most of the time, and my $3000 system went with the trailer when I bought a new one.

After a lot of research I'm convinced portable is the way to go. Both problems above are eliminated. In addition I can use it to charge other batteries, like the tow vehicle, boat batteries, or a neighbor in trouble.

I've been working with Dave at 4thdsolar after seeing his video on the performance of different manufactures of panels. The Merlin panels outperform other brands by a significant amount. He now has a kit for Airstreams and will be at the international in Doswell. Check it out: https://4thdsolar.com/collections/po...160w-solar-kit

[Dave-n-Janet]

I'm thinking a combination roof and portable may be best, especially if you store the Airstream where some sun is available, then don't need to run any shore power. The portable allows getting additional power when parked in the shade, but when gone for the day or even in partial sun conditions the roof top will be generating some watts. Of course, the roof top panels aren't likely to walk off either...but also there is not the hassle of always setting them out, following sun and securing.

[AirMiles]

Originally Posted by QC TORPEDO

I am having the dealer install solar panels on the roof of my '17 FC. It is pre-wired. Where will the controller end up?

I have the same ‘17 25’ Airstream and self installed 400W of solar and a Victron 100/30 controller on the solar pre-wire. It’s all documented with text and pictures in the “Solar Show and Tell” thread. The controller on my front queen bed model is under the bed in the front curbside corner next to the positive and negative busbars. There’s over 100 days of performance also documented on the above mentioned thread.

This system is working perfectly for me even in some fairly shaded locations. For the past two weeks I traveled the Blue Ridge Parkway and Skyline Drive and stayed at most of the tree filled national park no electric campgrounds and had no lack of battery power. The solar fully charged the batteries on all but two days and I never needed to use the generator for boost charging. You can see even on those two days when the batteries never floated, more than enough Amp Hours were returned to the batteries for the next day’s battery needs. This performance was also documented in that thread. But I attached it below updated through today.

The white area of the daily bar is bulk charging- basically to 80% charged. The light grey area is absorption charging- to 100%. And the dark grey is float charging to keep the batteries 100% charged.

[pteck]

Quality solar panels are commodity priced these days at roughly ~$1/watt. A single 100watt panel could be had for ~$100. Less if you find a sale. Definitely less when tax benefits are taken advantage of. At those prices , I'd recommend no less than getting 300W installed which is incrementally more equipment cost, yet about the same labor. 400W for the power user to never really have to worry about metering power. A 100W panel is a 100W panel. Sure, there's more efficient panels (by minor percentage points) costing more, at which point it's just better to put money towards another 100W panel than buying "better".

Factory wiring will easily support 400W. Some of the newer trailers reportedly have even larger gauge wire pre-installed. Just the same, 400W is fine. All parallel configured is a best practice configuration recommended by all professional outfits. Series parallel is a compromise that will create unnecessary interdependencies between panels with shading.

I agree with others that having 100W worth or portable panels for shaded conditions is good to have. Something like 300W on the roof and 100W portable should cover 95% of all uses.

[AirMiles]

Pteck, why do you persist in saying series-parallel is a “compromise “ when the Victron 100/30 operating manual clearly states it’s the preferred configuration for the most efficient use of the controller? Go look it up in the manual. Look at my performance just posted while staying in tree filled campgrounds on the east coast. If trees and shading was an issue as Pteck persists in saying, how would this performance be possible?

Study the actual performance data I’ve posted and then decide for yourself if the solar pre-wire works with a series-parallel configuration.

[pteck]

Originally Posted by AirMiles

Pteck, why do you persist in saying series-parallel is a “compromise “ when the Victron 100/30 operating manual clearly states it’s the preferred configuration for the most efficient use of the controller? Go look it up in the manual. Look at my performance just posted while staying in tree filled campgrounds on the east coast. If trees and shading was an issue as Pteck persists in saying, how would this performance be possible?

Study the actual performance data I’ve posted and then decide for yourself if the solar pre-wire works with a series-parallel configuration.

Frankly because it is. Please don't take this as an argument, rather than reasoning from a different perspective.

You're quoting Victron where they're primary applications are not necessarily RV based, rather static installs where shading is controlled and longer wiring considerations is their primary focus to optimize efficiency for.

It's not by chance that AM Solar installs RV systems with parallel wiring.

Your tests have shown you that you have a large system that produces plenty of power for your needs. What it does not show is a side by side comparison that parallel-series is better than all parallel.

Your tests have also shown you that there is an interdependency where shading 1 panel reduces 2 panels worth of output in a 4 panel series-parallel setup. An all parallel setup would not have that same consequence and at most would lose 1 of 4 panels worth of output under the same conditions as every panel is independent.

In RVing, it's about maximizing output for less than ideal conditions (i.e. shading). Not optimizing power for bright sunny days when there's plenty of power to go around, and to squeak out a few percentage points more production due to voltage loss or 10 gauge wiring. Solar generally operates at much less than peak for which the bulk of power is really produced.

I did not say series-parallel does not work. Only that it's not a best practice for the reasons stated above.

[AirMiles]

I’d love to see more data shared by those with full parallel configurations. Everything is a trade off. A series parallel system works better in low light situations. It starts charging earlier every morning and stays charging later every evening because it operates at higher voltage. It would also charge better on cloudy days for the same reason. But to gain these advantages, you have to give up something and that is if one panel of the pair gets significantly shaded it will lose the series connected pair. I’ve documented in real shade conditions this has very little effect. I’ve documented that if you completely cover one panel with a towel, the effect is drastic. How often do you get one panel in bright sun and the other in complete darkness in real life? Above I just posted my last twenty days of performance in tree-filled east coast campgrounds on the Blue Ridge Parkway. This isn’t some select data. It’s 20 days ending an hour ago. Check the time stamp on the picture and the post. A series parallel system works perfectly in real life in some of the shadiest campgrounds on the east coast.

I agree you could just connect the panels full parallel on the factory pre-wire as the system rarely operates at full voltage and losses would be insignificant. But why install a less efficient system when the more efficient system has proven to work perfectly in the real world?

[pteck]

AirMiles, please don't mistake my intent as ego or being argumentative. I'm not being persistent to win anything. As an engineer with significant systems and trade space experience to make the right design decision, I am only interested in the technical aspects of this. What I do believe is that it is important to present an accurate depiction of the factors for the next person who upgrades. These forums are also a knowledgebase after all.

Understand that I was at one point bullish about series-parallel. What a great way to handle the wire gauge issue that a notable installer likes to focus on here in the forums.

My research and analysis of the parameters do not support series-parallel as the optimal solution.

The charging earlier every morning is a fallacy. Every panel designed has a nominal voltage some 33% higher than the system voltage already. If there is enough light to generate any current at all, the system will produce power irrespective of series joined panels. My system produces sufficient volts to make power in minimal twilight.

Series panels are not an advantage to cloud cover. For the same reason they are a disadvantage in shade. A single shaded or cloud covered panel will have production impacts to series joined panels. This is a well understood fact that you can easily find in many resources.

I have 400W on my roof too. Again, I've researched this in depth prior to changing my opinion and making the design decision to go full parallel.

We don't have to agree as there's always more ways to skin a cat.

[Paprika]

"The charging earlier every morning is a fallacy. Every panel designed has a nominal voltage some 33% higher than the system voltage already."

This statement doesn't take into account the behavior of the charging controller. I've encountered a number of controllers whose manufacturers state that they won't begin charging in the morning until input voltage from the PV array exceeds battery voltage by 5 V. A series-parallel array will reach this threshold much sooner.

As for shading effects, I've seen arguments and real-world tests on both sides. In my own experience with 600 watts on the roof (and in wintertime, 200W on the ground) connected as series-parallel pairs, shading effects haven't been a problem. For me, the benefits of earlier startup and of cutting voltage drop in half for a given wire size make this a good choice in my situation.

[pteck]

Originally Posted by Paprika

This statement doesn't take into account the behavior of the charging controller. I've encountered a number of controllers whose manufacturers state that they won't begin charging in the morning until input voltage from the PV array exceeds battery voltage by 5 V. A series-parallel array will reach this threshold much sooner.

As for shading effects, I've seen arguments and real-world tests on both sides. In my own experience with 600 watts on the roof (and in wintertime, 200W on the ground) connected as series-parallel pairs, shading effects haven't been a problem. For me, the benefits of earlier startup and of cutting voltage drop in half for a given wire size make this a good choice in my situation.

You're chasing a red hearing.

1) If a 19V nominal panel is not making enough voltage, that's because there's literally not enough light for each cell within a panel to activate and generate the current to make it's .5V. Stacking more panels in series is still not going to generate enough current to make meaningful power even if it meets a voltage threshold.

You're optimizing some handful of watts in twilight, yet willing to lose whole panels and 100s of watts during bulk production to cloud and shading?

2) You should avoid those particular charge controllers.

[AirMiles]

Victron is one of the controllers that requires battery voltage plus 5 volts to turn on. I believe this is an important fact as to why they state the series-parallel configuration is preferred with 100 watt panels or single 200 watt panels in parallel. My series connected panels are one 18” fantastic fan apart. If one is getting shaded, they both are being affected by the reduced bright sky if not both in the shade. My parallel pairs are about seven feet apart. Many times the series pair may be shaded but the parallel pair is still in the sun. I can choose my campsite and the orientation of the solar panels on the site. I use the Lumos app on IPhones to make sure that I optimize sunshine on the site.

You are entitled to your opinion. I am posting hard data that shows my series parallel installation charges my battery bank nearly every day. I’ve posted about 140 days of actual use. I’ve used the system for 170 days all across the country from east to west and north to south. The only times it was not capable of recharging my batteries were under a thick canopy of Maple trees at one campsite in north western Wisconsin. The canopy was so thick that it appeared as dusk at midday. And at a nearly complete canopy of trees with multiple days of rain on the Natchez Trace Parkway. My batteries only have one day of available Amphours. If I don’t get significant solar charging every day, I have to run my generator. I’ve only run my generator five days out of 170, or 3 percent of the days. I consider a 97 percent success rate with solar completely acceptable.

Everyone can Study my usage posted in the solar show and tell thread and decide if my configurations historical production will work for them. Please start posting your experience with your 400W of parallel configured panels so everyone can compare the two configurations. Many provide opinions without data to back them up. I like to see the data that confirms the opinion. I look forward to seeing your data that backs up your opinion.

[daleyocum]

Originally Posted by QC TORPEDO

I am having the dealer install solar panels on the roof of my '17 FC. It is pre-wired. Where will the controller end up?

Airstream puts their tiny controller down with the "Rats Nest". Usually that's in the front of the trailer on the curb side. That might be under a bed or a seat. At least that's where it goes on 25' on up.

Airstream's controller and flexible panels are pretty low on the food chain of efficiency and durability. They're fine for keeping the battery charged in storage. If you plan on extensive boondocking, though, I'd suggest using a more efficient MPPT controller, like the popular Victron, and 400w of glass, not flexible, panels. Flexible panels tend to have a

short lifespan

. Even the smallest 100w panels can be had for around $200 each on sale. If you can fit bigger ones they can be half that.

[pcskier]

Pteck and AirMiles, I am enjoying your lively discussion here and on the Show and Tell thread. Lots of food for thought, and I'm doing a lot of thinking, as I just ordered the necessary gear for a 400w system. I will be documenting the whole process here http://www.airforums.com/forums/f448...-a-197517.html.

I am still torn on this debate of parallel vs series-parallel. Both seem to have their advantages. Someone like AM Solar or other vendor at some point needs to do a controlled, a/b test of both methods.

Obviously, each method is working well for you both. AirMiles, your results/experience is impressive. 97% successful charging days on the East Coast would have to translate to at least that here in the west. So here is the question I ponder though. Are your results *because* of, or in *spite* of, the series-parallel configuration. Too bad it's not easy to switch between the two by switching a few wires, and see what differences you may or may not note, in real life conditions.

I have a week or two to think some more on it until my gear arrives and I get to work. Given the copious sunshine here, I think either will be fine, but obviously, if we do all this work, we might as well maximize the efficiencies of the systems.

Thanks for the continued data and info from you both.

[pcskier]

Originally Posted by daleyocum

Even the smallest 100w panels can be had for around $200 each on sale. If you can fit bigger ones they can be half that.

I ordered 100w panels from Renogy yesterday for $106 each, on sale. Regular price around $135. The Zamps however do run are around $245 apiece, sticker price. I can't fathom the Zamps having enough 'better' quality to pay almost double for them. As much as I'd like to support "Made in America," that notion has its fiduciary limits for me!

[AirMiles]

I think there are many advantages to series-parallel and only one disadvantage. The disadvantage is that if one panel is getting shaded with the other three in bright sunlight, it affects both panels in that series. In real life, this has never been the determining factor that caused me to use my generator to charge my batteries. The benefits of series-parallel are increasing the charge on the batteries every moment the panels are working. Series-parallel is the most efficient configuration. It starts earlier in the morning and keeps running later in the evening. There is less voltage drop across equal size and length wires so it will provide more Amps to the batteries at all times except when a single panel is being shaded. I believe either configuration will perform acceptably over the factory prewire and one should use a parallel configuration if any panels have a high likelihood of being shaded by the A/C or other rooftop equipment.

My panels are located on the four corners of a single A/C Airstream. This layout has very low equipment shading potential and therefore works great with the series-parallel configuration. My configuration uses about half the length of wire on the roof which increases efficiency. It works at half the amperage which increases efficiency. It works at double the voltage which increases efficiency. Add up all those efficiency gains using your wire length/gauge voltage loss calculator and you will see why I chose series-parallel for my roof layout using the factory prewire.

[pteck]

I enjoy AirMiles posts, and his sharing of data is useful to show that his system works. Many things can be made to work in different ways. We're talking about which particular way - all parallel vs series parallel - works better. I'll present some points and I hope AirMiles does not take this as an attack on his system. But I will say some points made are flat out not true.

When one wants the most "efficient" system possible, there's no singular best interpretation of that. Personally, I want an efficient system that eeks out the most production - under the most possible compromising and mixed conditions. Not one that is most efficient under singular sunny day conditions (where there is no solar production deficit anyways if the system is sized appropriately). One can't dismiss shading and cloud causing inter-dependency losses between panels because that's going to be the predominant dynamic situation in RVing. Many of the same solar products we adapt to our RVs are used in more controlled static situations, so one must understand where some of the recommendations come from.

More importantly, it's going to be that particular challenging shade situation or rainy/cloudy day that causes solar generation shortfalls. If there were a situation to optimize for, it would be the compromised situation. An all parallel setup is going to be the ticket to salvage significantly more in those situations.

AirMiles great history of data shows that majority days are either:
1) Production greatly exceeds usage on good days. Wiring optimization is a non factor and won't put more power in a system that is full.
2) Cloud, shade, or non-optimal solar alignment days where peak generation losses over smaller gauge wiring is simply not an issue to mitigate because majority of solar charging happens at lower than peak levels - which the wire is plenty for.

Here's some data from my own full parallel system that disproves some of these notions:
http://www.airforums.com/forums/f448...ml#post2259405

[ROBERT CROSS]

....."The charging earlier every morning is a fallacy."

Is that before Sunrise?😂

360W ZAMP portable.

Bob
🇺🇸