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69Overlander · 11-15-2002, 08:27 PM

My wife and I recently bought a 1969 Overlander. We are planning on adding solar battery charging and bought an Evergreen 110w panel. My question- what is the best way to mount the panel to the roof? We bought a pair of Unirac tilting mounts, but I'm open to just mounting it flat if that's the best and/or easiest way to go. Also, does anyone have any tips on running the wires from the roof to the controller (which has to be mounted out of the weather) to the batteries?
We're very new to the Airstream world, so any and all information would be very much appreciated.
Thanks, Don

overlander64 · 11-15-2002, 09:51 PM

Greetings Don!

When AJL Solar of Lake Havasu City, AZ installed the solar system on my '64 Overlander (during the 2001 WBCCI International Rally at Sioux Falls, SD), they routed the wires from the panels through one of the DWV vent pipes for the bathroom (the one in the bedroom wardrobe). The installation is 18-months old and has been virtually trouble-free. My installation included two 50-watt panels and one 75-watt panel - - the 50 watt panels are mounted above awning rail height and the mounts are stationary. The 75-watt panel is mounted across the top of the roof toward the rear - - its placement was complicated by the air conditioner and bathroom Fantastic Fan.

Kevin

airstreamcaravel · 11-15-2002, 11:12 PM

A couple of thoughts:

I have read that the panels should NOT sit flat:

1. There allegedly is a need circulation for the back of the panel.

2. The panels should be tilted to the approriate number of degrees based on how far you are from the equator (for the maximum wattage in the cottage).

DMC

74Argosy24MH · 11-16-2002, 07:28 AM

Solar panels are not very efficient. Even at maximum sun a good panel's efficiency is about 15%. With clouds and a low angle it drops dramatically.
Any adjustable mount would have to almost be a gimbal, you never know how your trailer will be oriented to the sun. It would also have to be remote or automated control to follow the sun as it moves, either that or you will be climbing on the roof to adjust them constantly.

I gave up and mounted mine flat, figured it was the best way with all the limitations. I did raise them off the roof for air circulation, this also gave me a place to feed the wires beneath them. The mount is pretty simple, some angle and 1/8x2" strap. Remember these are fairly heavy and need to go through ribs not just skin.

John

john hd · 11-16-2002, 07:36 AM

i have been kicking the solar idea around and thought this might work.

instead of drilling into the roof and running wires out of vents etc. i was thinking of making a solar "briefcase". what i thought would work is a pair of solar panels mounted in a case that would fold up to face each other.

then you could take your solar briefcase out and set it up in the sun while leaving the trailer in the shade.

wiring would be a snap. as you could have a 12 volt extention cord coming out of the array with a standard 7 pin female trailer plug on the end. this way you could use your existing charge line.
no holes or mods. to the trailer! any charge control circuitry could be built right into the unit.

also if you own multiple units as some of you do, you could have one array to share between trailers. and if you sold or traded trailers you can keep the panels.

heck, you could even make a female to male adaptor and plug it into your tow vehicle to charge the batterys on that too.

to protect it against theft it could be locked to the trailers safety chains.(my father's suggestion)

what do you guys think?

john

74Argosy24MH · 11-16-2002, 08:51 AM

I like that, you could keep the trailer out of the sun. One of the things that I learned quickly is that solar cells are pretty useless unless facing 90? to the sun so you will still have to move them several times a day. But it would be better than mounted flat sitting in the sun all day and only really putting out decent power for 5 hours of the day.

John

69Overlander · 11-16-2002, 10:54 AM

Thank you all for your input. The picture is especially helpful. As our trailer is going to spend a lot of time in a remote location in the Sierra Nevada foothills, I'm afraid that a solar panel left out would either be stolen or trampled by wild pigs. So, I think we want to roof mount, accepting that our electrical output may be reduced.
Seeing that photo gets me started thinking about what we need to do, but it also raises a host of questions, namely:
How do you locate the ribs? Are they just where the rivets/screws are?
What do use to attach to the ribs- sheet metal screws?
How do we avoid hitting wires? (someone told me that the wire looms are attached to the ribs).
How do you seal the new holes so that they don't leak?
And, finally, how do you work on the roof without denting that beautiful aluminum?
Thanks in advance for your help. The more detail the better!
Don

74Argosy24MH · 11-17-2002, 05:53 AM

A couple of threads where working on the roof are discussed:

http://www.airforums.com/forum...&threadid=1428
http://www.airforums.com/forum...=&threadid=658

The vertical rivet lines that go around the trailer are where the skin attaches to the ribs. The horizontal rivet lines only attach 2 skins together so when on the room don't trust these for support. The line of rivets near the back edge of the panels in the picture above are where the skin is attached to a rib.

My MH wiring ran more the length of the body than it did along the ribs. There were holes in the ribs with rubber grommets where it passed through them. If you are careful when drilling holes you should have no problems. The rib and skin together are only about 1/8" thick, remember that when drilling and if there is a wire behind it you should not hit it. Rivets would be safer to use than screws, they don't have the length and sharp point. I would also rivet through to the skin in a couple of places between ribs, it will pull it tight to the mount and lessen any damage from vibration and wear. A bead of any good sealer will work around the holes.

John

davidz71 · 11-17-2002, 08:35 PM

69overlander,
Check www.rvsolarelectric.com for BigFoot mounts that can be used on curved roofs and also tilt mounts. One thing to consider, do you plan on waxing under the panels? Tilt mounts allow you to do this if a flat mounting system does not give you enough "standoff" to clean/wax underneath.

69Overlander · 11-17-2002, 09:57 PM

I did talk to RV Solar Electric and they've unfortunately stopped making and selling those Bigfoot mounts. I guess they didn't have enough demand to make it worthwhile...
Would something like a Pop Rivetool work for doing rivets through the roof and ribs?
Don

74Argosy24MH · 11-18-2002, 04:16 AM

A pop rivet tool will work. I would use 3/16" rivets through the ribs. Make sure the rivet is seated before clinching it or the mount will eventually move and not seal.

John

thenewkid64 · 11-18-2002, 06:19 AM

Even better than the Pop rivets would be to use olympics. They are installed like a pop rivet but are ALOT stronger. Also when the head is finished it is self sealing. You will still want to put some vulcum in the hole before inserting the rivet, but the head will not leak.

Just my $.02 worth.

69Overlander · 11-18-2002, 08:07 AM

Thanks for the info. I think I'm starting to see how to do this. As I look at the picture John posted, I'm assuming that the angles that run lengthwise on the roof are riveted at each rib they cross and at a few intermediate points through just the skin. And I'm wondering, just how strong are rivets? If I were to just do a mount at each of the four corners of the panel, how many rivets would I need to securely attach it?
Don

74Argosy24MH · 11-18-2002, 09:44 AM

I'm betting you won't get lucky enough to have the panel length the same as the spacing between ribs. If you are that would be ideal. I ended up with about 8" overhang on one end, 12" on the other, those panels are 55" long. The spacing on the ribs is not like studs in a house, every one is different. I think a lot has to do with window and door locations, the ribs fit around them. I used 1 1/2" x 1 1/2" angle, there is plenty of room for 2 rivets at each rib. The 2 panels and mount weigh about 30 lbs., the frontal area is not very big. My thought was gravity will hold it down, all I had to really do was overcome the air resistance. 8 rivets through the ribs and a few in between on each side will do that.

John

Bubbla · 11-18-2002, 11:19 AM

Hello Overlander,
I would like to write some of my thoughs about solar panels, and maybe you find them useful. I had the same problem like you to decide which panel and how to mount it. We spend about tree months of a year deep in the woods in Scandinavia with no access to power. I always hated it to run my Genset because of the noise and exhaust fumes. So finally I decided to go solar. My biggest concern was not to change the original appearance of the MH, and of course didn’t want to drill more holes then necessary. After seeking lot of internet, I found panels witch are about ½” inch thick and flexible. You can actually bend them exactly like your roof is. They don’t have to be mounted on any rack, you just glue them with some sicaflex or similar to your roof. No wind drag because the low profile, and actually you can’t even see them standing next to the MH. Last summer we tested the set up, and it was perfect. Didn’t have to start the Genset once. Always enough power in the batteries. If I somebody explain how to attach pictures, I would send one or two. You can find those panels on: http://www.solara.de Go to the yacht/boat section.
Excuse my bad English
alex

ALANSD · 11-18-2002, 11:45 AM

FOR THE PICTURE ATTACHMENT-
When you write your post or reply, go to the button below that
says
"browse"
click this and it will let you look on your computer for the pictures.
When you find one you want to use, double click its name, and that name and file location will be put in the box. (You click "open")
then when you submit your post or reply to a post, the picture will be there.
The only thing to remember is the size of the picture is limited and won't attach if it is too big.
Hope this helps, wish I could tell you in German!

Bubbla · 11-18-2002, 12:31 PM

Thank's ALANSD, I am still learning.
As you can see, you see nothing

alex

davidz71 · 11-18-2002, 01:06 PM

Alex,
Nice looking motorhome! Another source for flexible solar panels is www.unisolar.com for a comparison. Your english is just fine and we are happy to have you on the forum.

Bubbla · 11-18-2002, 01:59 PM

Yes, that's exactly them. We use two panels with 225W/D each. They have stainles steel backs, are very light and don't need any ventilation from below. As I said before, just glue them on and lets go camping

alex

davidz71 · 11-18-2002, 05:31 PM

Alex,
I thought they were a neat idea and you could throw them up on awnings, velcro them in place or just use bungie cords to tie them down. When it was time to go, unhook, roll them up and throw them inside.