Solar Panels on Cables question

[TrainChaser]

This question may have been asked already, but due to my ongoing mental issues of being "electrically challenged" (aka Don't Know Chit), I didn't even search.

A while back, there was a video of an interview Bob did with a van dweller who had some solar panels that were attached to the van via some very sturdy cables, so he could park his van in the shade and set the braced panels in the sun.

Question:  This gentleman seemed seriously intelligent, but I don't think I've seen any similar approaches on any video, and most people on the forums tend to go with anchored roof panels.

My question:  Are there really any serious problems with using separate panels on heavy-duty cables?  I'm thinking it's more of a personal-use issue, but I would like to make sure, as it looks like the best choice for me.  Right now, anyway; tomorrow may be different.

And please remember to give any explanations in small words and short sentences for the A.D.D.-afflicted. :dodgy:

 

[Optimistic Paranoid]

Pros:

In hot weather, you can park your vehicle in the shade to stay cooler, while the panels, placed out in the sun, recharge your batteries.  Obviously, this is more a thing for people who boondock in National Forests than those who boondock in deserts.

People who are, shall we say, tool challenged, might think this is easier than mounting the panels to the vehicle's roof, or paying someone to do it for them.

Cons:

You have to have somewhere in the vehicle to SAFELY store the panels when you are traveling.

If the panels were mounted on the roof, both the panels AND the alternator (assuming you wired your vehicle for this, and why wouldn't you?) would charge the batteries while you were driving.  If the panels were packed away inside the vehicle, that wouldn't happen.

The panels could easily be stolen while you were sleeping or away from camp.

The panels might blow over and break, or you might drop them and break them while trying to set them up and tear them down.

 

[B and C]

What Op said /\ /\

I put 2 - 100 watts on the roof so I don't have to mess with pulling out and putting away panels.  OTO I have 2 - 100 watt panels that I can lay out in the sun if I am under trees or it has been raining.

I used a 50 ft. 10 ga outdoor extension cord for the portable set and wired each set of panels in series to mitigate long cable runs.  When the portable panels are deployed they are connected in parallel to the roof mounted ones.  If I am not clear (who, me??), I wired the roof mount panels in series going to the controller and I have the portable panels wired in series that I extend through the extension cord.  This additional set is then wired in parallel with the roof set going to the controller.  No rewiring or changing any settings that way.  I like to think I have the best of both worlds

 

[BobBski]

I went with a portable 200 w system for a few reasons.  

1)  I'm in wooded areas more often than not and low hanging branches, tree sap, falling tree branches, etc are a concern when driving into remote locations

2). Wanted to be able to easily clean the panels without going up on the roof.  In my 60s I'm not as spry as I once was.  Also panels wouldn't be exposed to oil and road grime while traveling.  Most van and RV roof tops get pretty dirty in a short period of time, not to mention hail damage.

3).  Like the idea of parking in the shade and putting the panels in the sun as well as adjusting angle of need be.

4). It allows me to still have the space for a rooftop AC unit, in the future if desired.  I also carry a generator and wired the van with 120 shore power.  Prevents me from having 
to drill additional holes should I decide to change to different dimension panels in the future.

Panels are joined in series as well due to longer runs of cables, and joined the panels together with angle iron at the top and bottom..  The cables stay permanently attached to the charge controller (properly anchored).  I only use a 20' run but do have an additional 20' that I can "plug and play" if needed.

I planned for storage as well and the fit great , vertically in the "garage" resting on a double thickness of foam for road shock and kept the foam they were shipped with to further protect the glass.  1 simple bungee cord prevents any movement.  Setup or tear down takes all of 5 minutes.

Wiring panels in series also brings another thing into play.  Your panels are now sending 24 volts to the batteries so a good MPPT charge controller is needed to convert it back to 12 volts prior to sending to the batteries.

Here is a short 50 second video I made of my system 

 

[jimindenver]

In the past I have run my systems portable, everything from 235w to 750w. There are pros and cons to both mounted and portable, in the end I chose both.

Lets look at what you don't get from a portable that you do with a mounted panel. Mounted panels charge all the time while on the road, in storage or while in use. They don't tend to walk away and can even be made to tilt to get the best from them.

A portable panel charges nothing while stowed. Any portable system of any size is going to take up a lot of space and be a hassle to deploy and adjust. They are more likely to walk away unless attached somehow and can be subject to damage even if they are as tough as nails. The big advantage besides not having to mount them is that they can be moved to the sun and follow it from sun up to sun down. That easily doubles the output of the portable vs a equally sized fixed mounted panel.

I will have both the big system mounted on the trailer as well as a panel mounted on the truck. That panel will tilt and I can adjust the truck through the day if needed. That will let me use the portable to catch those yummy early rays while the big system is barely awake, take full advantage of the clouds breaking any time of day in bad weather and have at least something charging while the trailer is shaded.

on another forum a member has his panels on the side of his class C where they can be tilted up or removed as portables.

 

[BobBski]

Forgot to add, on real windy days I just lay them flat elevated by 4 tent stakes for air circulation or use 2 adjustable walking sticks to tilt them.

 

[BobBski]

Please bear in mind, I'm not for or against either method and not trying to convince anyone which is better. If I was younger or didn't have a high top van, I'd have probably gone with roof mount. I will say I was a very resistant convert to solar of any kind but now see that I would be missing the boat if I hadn't incorporated it into my build. These CRVL people can be very convincing

 

[TrainChaser]

Those all seem like good responses, so thank you!

I don't think that I will be traveling extensively, more like doing a park-&-charge, due to limited finances.  

I understand the climbing and cleaning bit -- I, too, am in my sixth decade.  While I spent my childhood climbing a ham radio tower, I don't do so much of it now.