Solar Options

[bellepente]

Hello all -

I'm new to this forum, and relatively new to airstreams and boondocking as well ... we bought our trailer second-hand a few years ago, and have used it mostly for long week-ends here in Oregon ... we are planning an extended road-trip around the west this summer (2-3 weeks) ... although we will occasionally stay in places with hook-ups, 2/3 of the time we will not, so I am considering getting a solar set-up to keep the battery charged ... we are relatively light power users, and I have no interest in hauling around a generator.

I've read the most recent posts on this topic, and done a little research. There seems to be three viable options:

1. Portable system from CEA Solar
2. Roof-top installation from AM Solar
3. Roof-top installation of Zamp system (from local Airstream dealer)

There has been some discussion (all very postitive) about the AM system, but virtually none about the Zamp. Does anyone have any thoughts on the relative merits of the two solutions?

Also, any thoughts on the roof-top vs portable option? Of course the possibility of theft is always a consideration with the portable, but the idea of being able to park in the shade and run a 40' cord to a sunny patch in the campsite is pretty compelling...

Thanks!

[tpi]

I went with roof top system. A real big advantage is the batteries are charged/maintained while stored. Before the solar, if I had a deficit in the batteries I'd have to pull the trailer home, charge for hours, then take trailer to storage lot.

I have 200 watts of panels on the roof, and I've seen max of about 12 amps into my two group 24 batteries. Since the wiring passes through the back of the refrigerator area, I don't see any reason why I couldn't install a connector for additional portable panels (my controller can handle it). FWIW I didn't use any of the Airstream factory solar wiring, I used heavier wiring.

Also, consider LED lighing, and any low draw appliances you would need. I found a 26" Vizio TV which draws less than 30 watts, I see a Macbook Air draws 9 watts at idle (screen up), and 20 watts in use. Saving can be as good as adding battery/solar capacity.

[Protagonist]

Welcome to the AirForums!

Originally Posted by bellepente

Also, any thoughts on the roof-top vs portable option? Of course the possibility of theft is always a consideration with the portable, but the idea of being able to park in the shade and run a 40' cord to a sunny patch in the campsite is pretty compelling...

Over the next few days, you'll probably see posts advocating portable systems, rooftop systems, rooftop supplemented with portable panels, and some trying to change your mind about generators.

My advice is, if you're dead set on using solar-only, add up all of your current draw over a typical 24-hour period, and get enough panels, and large enough panels, to generate that much power in an 8-hour period of sunshine. Then, make sure you've got enough storage capacity in your batteries to get by for about three days of no sun at all, as well. Ideally, three days of no sun should only drain your batteries by 30%, and certainly no more than 50%.

Unless you've got a large amount of open roof space, that scheme pretty much dictates that at least some of your charging capacity will come from portable panels. Such is life.

[mefly2]

We have good luck with a Goal Zero "briefcase" charging panels / unit + GZ auxilliary battery pack for small electronics / emergency 12vDC.

[AirsDream]

Originally Posted by Protagonist

Uness you've got a large amount of open roof space, that scheme pretty much dictates that at least some of your charging capacity will come from portable panels.

That's sort of what I was thinking. A 16 footer has pretty limited availble roof real estate ...

I mostly boondock, so I thought about this a lot. But I only momentarily considered portable panels, because of the theft and where-to-put-it-while-en route issues, but I had plenty of available roof area to put two largish (AM Solar) panels and also had room for three batteries. The very thought of having to get out the panels and some sort of support for them, string cables, etc. gave me the willies ... this was supposed to be about "easy" and "no hassle." I also considered several extra batteries in the bed of my pickup truck, along with BIG cables to connect to the trailer. But then I thought that If I were gonna' do either the portable-panel thing or the batteries-in-bed-of-tow-vehicle thing, why not just use a generator for a couple of hours a day and haul along the gasoline and extension cord, run the cord from trailer to generator, put it away again, chain up the generator against theft, etc. etc. etc. So I didn't do either.

Spring, fall, winter, I park in full sun whenever I can. Summer gets a little dicier because of the heat. Now, there are a few summer days when I wish I had more shade and less electricity. But then again, there are some summer days when I wish I had more cold beer, also. I get by fine, however - where I camp (YMMV) - by finding parking with morning sun and afternoon shade and run Fantastic Fan and Fantastic Vent to keep cool. It takes a little doing, but it's possible. Even in winter, my batteries are pretty much fully charged by about 10 a.m., so I don't need all that much sun.

So: if you've got room for roof panels, you ought to at least consider that, because it's so convenient. They're hard to steal, and they're just up there quietly working while you are opening a chilly one, reading a book, chasing a trout, etc. But at the end of the day, you've gotta' be happy with what YOU do, not what I or someone else does. Glad you're thinking it through in advance. Good luck in your quest.

[lapple001]

Good to see some current postings on solar, I have some planning to do too.
I'm about to go there, looking at the 80W portable panel, should be enough to refill an evening's conservative consumption. My question is about batteries. I have the standard 2 deep-cycle batteries but "some say" glass-mat (AGM) are preferred for a solid set-up.

Any thoughts?

[lapple001]

one more thing - I had a good telephone conversation with Brian at Colonial Airstream up in NJ. They sell the Zamp product and Brian is willing to teach about it.

RV Solar Panels from Colonial Airstream: Zamp Camper and Travel Trailer Solar Panels

[lapple001]

and another note, found this on another forum

http://www.airforums.com/forums/f37/...bie-90938.html

most talk about solar to maintain in storage and generators on the road but the last guy has a 19', running solar, ends on a positive note

[AirsDream]

I'd suggest that you go to the AM Solar web site Welcome to AM Solar_Your RV Solar Specialists since 1987 and read their "education" pages. This will give you a lot of basic information about batteries, charge controllers, and RV-based photovoltaic systems in general.

As to AGM batteries, there are significant pros and cons. The biggest downside is cost. They are a lot more expensive than plain flooded cell batteries. Mine were nearly twice as expensive. There are three significant upsides. First, assuming proper charge regimes, no water maintenance is needed. Second, no acid leakage absent some catastrophic occurrence, so vastly reduced corrosion opportunities. Third, they have significantly lower internal resistance, so they can be bulk charged at much higher amperage rates (assuming you've got the power to supply the amperage!) than flooded cell batteries, so they reach a high state of charge much faster.

There is one more potential advantage: again given proper charge regimes, and this means a three stage charger, proper attention to manufacturer's suggested voltages during charge, tracking battery temperature during charging (a quality controller will do this automatically), etc., they are rumored to last perhaps twice as long as flooded cell batteries. I have no personal experience here - mine are only three years old and according to the meters, are performing as they did brand new ... so time will tell. I do have an eight year old Concorde battery in my motorcycle, and it is starting to show signs of weakness ...

There is also a lot of information on the Lifeline brand of AGM batteries - including some specifically designed for solar charging - on the www.lifelinebatteries.com website. This is a link to the tech. manual for their solar charging battery brand: http://www.sunxtender.com/pdfs/Sun_X...cal_Manual.pdf and it has a raft of information about charge rates, Peukert plots of discharge rates vs. time, etc. These brands are mfd. by Concorde, which has been the standard in aircraft for many years, and appears to be the RV brand of choice if you want to pay the steeper AGM price of admission.

I'm sure others will chime in with info. on other brands ... my only experience has been with Lifeline / Concorde, and it has been a very good experience - at least once the sticker shock wore off. I'm sure that if I had a fixed-base photvolataic system, I'd stick with conventional flooded cell batteries and just maintain them regularly. And if you have a single stage constant-voltage charger, it will quickly ruin both flooded cell OR AGM batteries ... though the received wisdom is that flooded cell batteries are slower to be ruined than AGMS (plus they're a lot cheaper to replace when they're shot!)

But at least to me, the difference in ease of use outweighs the price differential. YMMV.

[ROBERT CROSS]

Originally Posted by bellepente

Hello all -

I'm new to this forum, and relatively new to airstreams and boondocking as well ... we bought our trailer second-hand a few years ago, and have used it mostly for long week-ends here in Oregon ... we are planning an extended road-trip around the west this summer (2-3 weeks) ... although we will occasionally stay in places with hook-ups, 2/3 of the time we will not, so I am considering getting a solar set-up to keep the battery charged ... we are relatively light power users, and I have no interest in hauling around a generator.

I've read the most recent posts on this topic, and done a little research. There seems to be three viable options:

1. Portable system from CEA Solar
2. Roof-top installation from AM Solar
3. Roof-top installation of Zamp system (from local Airstream dealer)

There has been some discussion (all very postitive) about the AM system, but virtually none about the Zamp. Does anyone have any thoughts on the relative merits of the two solutions?

Also, any thoughts on the roof-top vs portable option? Of course the possibility of theft is always a consideration with the portable, but the idea of being able to park in the shade and run a 40' cord to a sunny patch in the campsite is pretty compelling...

Thanks!

For the straight scoop on solar for your application I would contact Lewster here on the Forum.

We Camp in DEC forest sites quite often and decided that a large solar array is not practical for us. 30w of flexible panels when sol is available, along with a three stage converter and 2 Lifeline 100ah grp27's have worked very well.
Paying close attention to power usage is most helpful in extending battery time.

Disclaimer....we do use a Honda 2000i when needed. Insurance.

Stream Happy

Bob

[Skater]

The original owner of our trailer installed three 70 or 75 watt panels on the roof; given their age they're probably now 60-65 watt panels. I upgraded the basic solar controller to one with three-stage charging. They'd also installed a third battery.

We took it dry camping for the first time about two weeks ago, and even with using the furnace overnight, the water pump for our showers, and charging our phones and iPad, we were still fully charged pretty early in the day. We have a generator but I never got it out. It was great. We were parked in full sun and had a gorgeous sunny day for those panels to soak in. I think a side effect of having the panels is that the sun isn't on the trailer in those spots, so the trailer stays a bit cooler too.

Our trailer is a 30', so we have a bunch of roof space, and I'm pretty sure the original owner intended to cover all the free space with solar panels - there's not much left up there. As others said, your 16' trailer is going to have a lot less. If you can do without some things (TV antenna?) you might scratch up a bit more for solar panels.

Keep in mind you don't have to do it all at once either - you can size the wiring and charger for the largest array of panels you could fit, but then just buy one panel now to get started and see how it goes.

[Airstream25]

Originally Posted by bellepente

Hello all -

I'm new to this forum, and relatively new to airstreams and boondocking as well ... we bought our trailer second-hand a few years ago, and have used it mostly for long week-ends here in Oregon ... we are planning an extended road-trip around the west this summer (2-3 weeks) ... although we will occasionally stay in places with hook-ups, 2/3 of the time we will not, so I am considering getting a solar set-up to keep the battery charged ... we are relatively light power users, and I have no interest in hauling around a generator.

I've read the most recent posts on this topic, and done a little research. There seems to be three viable options:

1. Portable system from CEA Solar
2. Roof-top installation from AM Solar
3. Roof-top installation of Zamp system (from local Airstream dealer)

There has been some discussion (all very postitive) about the AM system, but virtually none about the Zamp. Does anyone have any thoughts on the relative merits of the two solutions?

Also, any thoughts on the roof-top vs portable option? Of course the possibility of theft is always a consideration with the portable, but the idea of being able to park in the shade and run a 40' cord to a sunny patch in the campsite is pretty compelling...

Thanks!

Consider that your solar panel 40' away on the ground might grow legs and never be seen again :-(

I went with a roof top mount, no set up required each time you reach camp and it maintains the batteries when in storage.

[arodriguez60]

you may get some info on solar from Marc Loring mloring@roguepowertech.com. He is in Ashland Oregon. Small company that makes a very good MPPT controller. His factory is run by solar and the entire controller is made locally. I have had his controller on my trailer for over 4 years and am very happy. Great support .

[herrick51]

Hello,
I would not recommend a 80 watt portable unless you buy two.I have a 120 watt and you only generate about 6.7 amps.Two 80's will get you 10 amps or so under ideal conditions.INMHO,size 27 batteries should be the minimum and Glassmat preferred. ALSO,unless you rewire the portables,any length longer than 15 feet is contraindicated. Best regards following the sun

[TG Twinkie]

I just put together an 85 watt panel and controller (10 amp). I made it portable. The max output is just under 5 amps. I have one group 24 in the trailer and a group 27 that I can plug in and run parallel with the group 24. I have the system wired to where I can charge either one of the batteries independent of the other or charge them together. Both batteries are RV/Marine lead acid type.
If I have shore power I can charge both batteries with the converter. I can also charge the group 27 while driving if I am not pulling the trailer .
We are headed out on a 10 day dry camping run in a week. I will report back on how it went.

[TBRich]

We have both a factory 600w inverter and factory solar on our 19' Bambi, which we like having very much. It keeps the batteries topped if there's good sun and there usually is in our neck o' the woods. But there's only room for one 53 watt panel from the factory on a Bambi...you'd have room for more on a larger rig, of course, which would be desirable. That having been said, if I had it to do over, I'd probably not get factory solar and have it added...you can get a better system and more watts. The inverter is handy, though you can easily work around it it needed. It will run the TV and charge electronics. In fact that's what we use it for mostly when we're dry camping and the generator isn't running.

[barts]

We have 200W of AM Solar panels on the roof, and have converted the interior to all LED lighting on our 25' Tradewind. This easily runs my CPAP machine (via a 1000W inverter) and provides night time illumination, reading, etc. We don't have a TV; it does readily charge cameras, phones, laptops. etc, as well as running the water pump, electronic ignition on fridge and water heater, etc.

In full sun, we're generally charged back to 100% (according to our handy Tremetric battery monitor) before 1:00 pm.

If you need microwaves, hairdriers, etc, this may not work for you... but for us this has kept us completely generator free.

- Bart

[bellepente]

Thanks to everyone for the helpful comments and suggestions so far!

We're going to do the "demand side" improvement of LEDs, and add more battery capacity on the "supply side". And since it appears that I have room on the roof for (2) ~2x4 ft solar panels (one on either side of the roof vent) by sacrificing (not really a sacrifice except maybe for resale value) my never-used TV antenna, we are considering going that route.

So we're down to the dilemma of choosing between an AM Solar 200 watt system with a 25 Amp controller (installed by AM) or a 190 watt Zamp Solar system with a 30 Amp controller (installed by our local airstream dealer). The AM system has slightly smaller and more powerful panels and is a little less expensive, but the Zamp seems to be a more integrated system (perhaps more like buying a Mac than a Windows PC?).

Any thoughts on the relative merits of these 2 solutions?

Please feel free to send a private message or email if you prefer...

Best regards, Brian

[AirsDream]

Does the Zamp system use an MPPT controller? I looked on their website (never heard of them before, sorry!) and didn't see mention of that, and I know that I've seen higher current flows from my (AM Solar) system than they spec. - I'd be sure about that, as MPPT will get you quite a bit more charging current when conditions are right.

If I were you, I'd call AM or Lewster and get some personal advice from pros. They are of course AM Solar biased, but they're also quite happy to talk pros and cons, and they REALLY know photovoltaic systems. Sounds as if you can't go too far wrong with either one ... good luck!

[lewster]

Brian, it's like apples and oranges.

AM Solar has been in the business for 25 years; designing, manufacturing and installing RV solar systems every day and your dealer might have a tech who does it ocassionally. As far as 'system integration', how is any add-on solar charging system more integrated than any other except for the expertise of the installers and the compatibility of the equipment? The mere fact that a system is sold by a dealer does not immediately make it more 'integrated'.

My answers should be obvious, but it's your trailer and your decision.

Originally Posted by bellepente

Thanks to everyone for the helpful comments and suggestions so far!

We're going to do the "demand side" improvement of LEDs, and add more battery capacity on the "supply side". And since it appears that I have room on the roof for (2) ~2x4 ft solar panels (one on either side of the roof vent) by sacrificing (not really a sacrifice except maybe for resale value) my never-used TV antenna, we are considering going that route.

So we're down to the dilemma of choosing between an AM Solar 200 watt system with a 25 Amp controller (installed by AM) or a 190 watt Zamp Solar system with a 30 Amp controller (installed by our local airstream dealer). The AM system has slightly smaller and more powerful panels and is a little less expensive, but the Zamp seems to be a more integrated system (perhaps more like buying a Mac than a Windows PC?).

Any thoughts on the relative merits of these 2 solutions?

Please feel free to send a private message or email if you prefer...

Best regards, Brian