Solar power funky idea

[Del Gurney]

Just waxed "Tinbad" and am getting ready to finish the replacement of the plastic chrome trim between lower panels and banana wrap when I remembered that I had removed my body panel rock guards to clean and wax.
Then recalled all the dings in the guards.
Yes, I'm leading up to something so bear with me.
I've always wanted to add solar charging to the trailer so I'm just going to throw this out there for critique.
First I'm going to Rhino the guards outside....probably in black is I've seen pics of others and it looked ok.
Next revise the hinge system for quick removal (the trailer looks cleaner when they're not on.
HERE is The BIG QUESTION:
I would like to consider adhering solar panels to the curved inside of the guards and have a quick connect system and separate "stands" made so I could place them for best effect facing the sun.
I've seen ad's for flexible solar collectors and I'm not too keen on drilling holes in the roof for the standard set up.
The "surface area" looks close if considering both guards used.
In my current situation I would need to run 25' of wire to the outside of the barn (voltage drop?)
What do you think?
Thanks
Del

[wmarsha]

Placing the collectors on the roof is a compromise; having separate collectors requires a place to store them-pita. What you have suggested is brilliant! I think you should do it; I think Airstream should do it; I think AM Solar ought to do it. I think I will do it. sheez, that is a GOOD idea. Yes, I know the rock guards take a beating, but with the addition of the Rhino Lining, rock impact will be reduced; plus an air gap between the guard and the actual P-V Cells will prevent any damage; the approximate shape will NOT be perfect but will still concentrate rays; if in direct sun, they can be moved to eliminate overheating; if in low sun they can be moved to increase exposure. ZampSolar is the outfit that makes portable collectors, so perhaps they're the ones to contact. (Power to Explore! | Zamp Solar). The wiring can be via a plug or a "drop light" type of reel, or whatever form you wish it to take; controller can be mounted up around the tongue/batteries or wherever most convienient. I think this is a great idea!

[Skater]

I get that my rooftop solar installation might not always be getting the best sun for most power generation. But keep in mind you're out camping, trying to relax, so I'd suggest avoiding the temptation to keep moving around your portable panels to get the best sun. At some point it'll stop being fun.

[Del Gurney]

Thank you both for your replies.
I'm just thinking about it so far and realize I'll need to do some more investigation as there may as yet be pit falls I can't see.
In my situation, I'm a full-timer with a trailer in a barn with full sun exposure on south side so placing on the roof at this time would be fruitless.....I need something movable, compact and un-obtrusive.
Anyone else have comment on the more technical (electric) aspects of this idea....I think I've got the mechanics of hinge/stand worked out.

[TG Twinkie]

I have an 85 watt portable solar panel that I plug in to a receptacle on my trailer. While it does take some effort on my part to set up. I feel it is worth it.
During our last 10 day dry camping trip I might have spent 20 minutes out of the day changing the position of the panel to get optimum sun exposure. It resulted in the full 10 day stay using only 1 group 24 lead acid battery and never having even a low battery, not to mention a dead one.
While somewhat conservative on power usage, we didn't feel we were deprived. We watched a few movies on the TV, used the water pump and lights as though we were on shore power. Even ran the 120 volt electric vacuum cleaner at least every other day.
I had been considering a generator, and will still look at one if we need A/C. But at this time I don't see the need.
We are headed out on a 3 week trip soon, about half of it will be dry camping. Still plan on using the solar panel and 1 battery.
I don't think I spend any more time with the solar panel than one would with a generator. Beside the panel doesn't use any gas or oil.
Oh! One other thing. The solar panel dB output is 0 at any distance.
The panels are supposed to be designed for outdoor use, meaning rain, snow, hail etc. So they should stand up to somewhat of a beating.
I think your idea is a great one.

[wmarsha]

I have contacted these folks to see what they have to say. I will report back as soon as I know. Now there is another thread asking about solar panels, so this oughta be bumped back on the portal.

[rumrunner]

With a 25' run you might need some fairly large conductors to avoid undesireable voltage drop. I have seen some professional installs with 4/0 welding cable for runs as short as 10'. If you are not worried about getting the maximum charge, just want to try it out, use what you have. Good luck and be sure to keep us in the loop.
tim

[TouringDan]

Twinkie

I like the sound of what you have done with your portable 85 watt solar panel. Could you please provide some details.

Thanks, Dan

[Del Gurney]

Thanks again for everyone's input:
To Banjobill: I contacted your source in Everett Wa. and they don't sell flexible panels. In our conversation they did'ent see a problem "right off the bat" other than cost....but offered encouragement saying "this is how progress is made."

Looked into West Marine and they do (I'm a boat guy). So I'll look a bit deeper in to this though it's become obvious it'll be more expensive than a flat panel.

This is more a matter of using the rock guards for more than one purpose and space/weight saving at this point. And no holes in the roof and "possible drag"?

I watched a couple instructional video's today and see that a real pro will be required to ensure I don't make a total ass of myself on this job.

I love "projects" and if I can find a reasonable way to do this I'll provide all details. And if anyone else get's there first please let me follow in your footsteps.

Thanks again

[TG Twinkie]

TouringDan
I bought a single 85 watt solar panel and controller. I built a cover for the panel that is hinged. The cover serves two purposes. One to protect the face of the panel when stored. The other to provide a stand for the panel.
When the cover is folded open to expose the panel to the sun, it looks like a small pup tent. When fully opened the cover holds the panel at about a 55 degree angle. I can adjust the cover from the 55 degree angle down to the point where the panel will lay flat on the ground.
The controller is mounted on the cover and wired to a 15' cord (3 conductor #10 SO type) with a 7 pin plug on the end of the cord. I mounted a 7 pin receptacle in the side of the trailer adjacent to the battery compartment. It is the same 7 pin connector used on the UCord. But only 2 pins are wired. The common/ground pin and the pin for the charge line. I wired the receptacle to the battery and have a 30 amp fuse in the positive wire.
So it is a simple matter of setting up the panel at the right angle and plugging it in to the receptacle on the trailer. When I set the panel up for the morning sun, it is at it's steepest angle, 55 degrees. The sun does not have to be much above the horizon to hit the panel at a straight on shot. As the day progresses I adjust the angle to where by noon or the panel is lying flat on the ground. When the sun has reached it's peak and starts to get lower in the sky I rotate the panel and adjust the angle up as the sun gets lower. I don't use any fancy protractors or device to get the angle perfect. I just stand in front of the panel and use my shadow to adjust the panel left or right and up and down.
At the same time that I wired up the solar panel I wired in an 1100 watt inverter. The meter on the inverter gives me an indication of what the charge level is on the battery. While the inverter is not on continuously I can turn it on momentarily to check the battery voltage.
I do carry a group 27 battery in the back of my truck, just in case there is a need for more ampere hours, such as running the furnace for an extended period. The battery has a male and female 7 pin connector wired to it. With the battery in the truck I can charge it while driving and not towing by plugging it into the receptacle for a 5th wheel trailer inside the box. I can also place the battery next to the trailer and plug it into the same receptacle that the solar panel plugs in using the male connector wired to the battery. At the same time if I choose to use the solar panel, I can plug it in to the female receptacle wired to the battery. Thus charging both batteries.
At this time I carry the panel on one of the twin beds when traveling, I am considering raising the bed platform and making a drawer just below the mattress level to store the panel. But so far the bed storage has worked.
Hope this helps.

[vswingfield]

Clever idea. I appreciate the innovative thinking.

One question, though. How vulnerable to damage are the flexible solar panels? Could they be damaged by a rock denting the guard to which they are attached?

[AirsDream]

A couple of points: first, so far as I'm aware, holes in roof are not part of solar install. On mine, for example (AM Solar parts) - a ultra high strength 3m two-sided tape was used to mount the panel feet/standoffs, and I think that's the norm. Scared me when I heard of it, but my trailer's gone many tens of thousands of miles with them up there, with no issues. My reading on this tells me that the surface prep. has to be done right, but that if so it works o.k.

Second, the flexible, amorphous panels have significantly lower output per square meter than monoccrystalline or polycrystalline (rigid) panels ... but on the other hand, that area inside the "segment protectors" is otherwise wasted.

So overall, I think this might be a pretty good idea. I do know that some folks on the Forums have taken amorphous panels and "glued them down" on the roof (I'm not sure how), following the roof curvature. I seem to recall, however, that it works. One big advantage to the on-the-roof position is that the panels are exposed to sunlight and doing their jobs even if the trailer is going down the road and also when in storage.

Intriguing idea. Do, please, keep us posted.

[mjayjensen]

This is a very interesting idea. i would like to receive updates.
Thank you,
Jay

[jmpratt]

Originally Posted by rumrunner

With a 25' run you might need some fairly large conductors to avoid undesireable voltage drop. I have seen some professional installs with 4/0 welding cable for runs as short as 10'. If you are not worried about getting the maximum charge, just want to try it out, use what you have. Good luck and be sure to keep us in the loop.
tim

Conductor size is a function current and wire length. For a given conductor size you will have a voltage drop per foot per amp. Figure out what your max current will be then look online at an ampacity chart. Then buy some 10 or 12 gauge wire. 4/0 welding cable is extreme overkill.

[lewster]

Originally Posted by jmpratt

Conductor size is a function current and wire length. For a given conductor size you will have a voltage drop per foot per amp. Figure out what your max current will be then look online at an ampacity chart. Then buy some 10 or 12 gauge wire. 4/0 welding cable is extreme overkill.

Somewhat correct, but look at the installation instructions for any Magnum inverter and you will see that for any for any run from batteries over 400 amp/hours, 4/0 is the minimum wire gauge recommended. Nothing under 2/0 is ever recommended for even very short runs.

Plus, 12 AWG is too small for anything other than perhaps a 100 watt solar panel (we actually use a minimum of 10AWG for panel runs to the roof top combiner box) and a minimum 8AWG up to 2AWG for the run from the box to the controller, and then to the batteries. But perhaps you have other proprietary knowledge that AM Solar (in the RV solar business for over 25 years) does not.

[mefly2]

Innovative as long as the segment protectors don't grow legs and walk away. We have a goal zero "briefcase" panel for emergency charging.

[jmpratt]

Originally Posted by lewster

Somewhat correct, but look at the installation instructions for any Magnum inverter and you will see that for any for any run from batteries over 400 amp/hours, 4/0 is the minimum wire gauge recommended. Nothing under 2/0 is ever recommended for even very short runs.

Plus, 12 AWG is too small for anything other than perhaps a 100 watt solar panel (we actually use a minimum of 10AWG for panel runs to the roof top combiner box) and a minimum 8AWG up to 2AWG for the run from the box to the controller, and then to the batteries. But perhaps you have other proprietary knowledge that AM Solar (in the RV solar business for over 25 years) does not.

Yup, battery to inverter is high current (roughly 10 times inverter output current) so thick cables are required. However, solar panel to battery will not have high current. A 120 watt solar panel will put out about 8.5 amps at 14 volts. 4/0 cables will be overkill for solar panel to battery connections unless you plan on having 3600w solar panels.

[Uzzah]

Originally Posted by TG Twinkie

TouringDan
I bought a single 85 watt solar panel and controller. I built a cover for the panel that is hinged. The cover serves two purposes. One to protect the face of the panel when stored. The other to provide a stand for the panel.
When the cover is folded open to expose the panel to the sun, it looks like a small pup tent. When fully opened the cover holds the panel at about a 55 degree angle. I can adjust the cover from the 55 degree angle down to the point where the panel will lay flat on the ground.
The controller is mounted on the cover and wired to a 15' cord (3 conductor #10 SO type) with a 7 pin plug on the end of the cord. I mounted a 7 pin receptacle in the side of the trailer adjacent to the battery compartment. It is the same 7 pin connector used on the UCord. But only 2 pins are wired. The common/ground pin and the pin for the charge line. I wired the receptacle to the battery and have a 30 amp fuse in the positive wire.
So it is a simple matter of setting up the panel at the right angle and plugging it in to the receptacle on the trailer. When I set the panel up for the morning sun, it is at it's steepest angle, 55 degrees. The sun does not have to be much above the horizon to hit the panel at a straight on shot. As the day progresses I adjust the angle to where by noon or the panel is lying flat on the ground. When the sun has reached it's peak and starts to get lower in the sky I rotate the panel and adjust the angle up as the sun gets lower. I don't use any fancy protractors or device to get the angle perfect. I just stand in front of the panel and use my shadow to adjust the panel left or right and up and down.
At the same time that I wired up the solar panel I wired in an 1100 watt inverter. The meter on the inverter gives me an indication of what the charge level is on the battery. While the inverter is not on continuously I can turn it on momentarily to check the battery voltage.
I do carry a group 27 battery in the back of my truck, just in case there is a need for more ampere hours, such as running the furnace for an extended period. The battery has a male and female 7 pin connector wired to it. With the battery in the truck I can charge it while driving and not towing by plugging it into the receptacle for a 5th wheel trailer inside the box. I can also place the battery next to the trailer and plug it into the same receptacle that the solar panel plugs in using the male connector wired to the battery. At the same time if I choose to use the solar panel, I can plug it in to the female receptacle wired to the battery. Thus charging both batteries.
At this time I carry the panel on one of the twin beds when traveling, I am considering raising the bed platform and making a drawer just below the mattress level to store the panel. But so far the bed storage has worked.
Hope this helps.

Could you just plug the panel into the umbilical receptacle at the front of the trailer where the TV plugs in?

[TouringDan]

Twinkie

Thanks for the details and I really like your creative thinking. Sounds like it all works well for you and is all very flexible. Some photos would be helpful too, to kind of fill in the blanks.

Thanks, Dan

[lewster]

Originally Posted by jmpratt

Yup, battery to inverter is high current (roughly 10 times inverter output current) so thick cables are required. However, solar panel to battery will not have high current. A 120 watt solar panel will put out about 8.5 amps at 14 volts. 4/0 cables will be overkill for solar panel to battery connections unless you plan on having 3600w solar panels.

If you actually read my post, you would see that the maximum for solar panel to controller to battery runs is 2AWG. 4/0AWG is only mentioned for battery to inverter connections.

"Somewhat correct, but look at the installation instructions for any Magnum inverter and you will see that for any for any run from batteries over 400 amp/hours, 4/0 is the minimum wire gauge recommended. Nothing under 2/0 is ever recommended for even very short runs.

Plus, 12 AWG is too small for anything other than perhaps a 100 watt solar panel (we actually use a minimum of 10AWG for panel runs to the roof top combiner box) and a minimum 8AWG up to 2AWG for the run from the box to the controller, and then to the batteries. But perhaps you have other proprietary knowledge that AM Solar (in the RV solar business for over 25 years) does not."