Roadtrek 400W solar Panel Install (Pic Heavy)

OK, I broke down and ordered 4 - 100 watt flexible panels    Sorry Renogy, yours were not available and I am out of time

Anywhooo, I am rethinking my overall install.  Originally I was going to have all 4 panels as remote panels.  Figuring out finally; that I am lazy after all,   I want to mount two to the roof of the fiberglass top Roadtrek and keep two as supplemental to put out when needed.  Taking care of two external panels will be easier than 4.  I have limited space on top so I can only mount two.  I plan on running the cables from the panel down the top of my grey water vent on the roof and then drilling a hole in the vent pipe inside (and sealing) to route the cables to my controller inside (already installed).  

Since I am putting these panels on top, I was thinking of using the packing material (some kind of closed cell foam) to hold them up off the roof a little to keep them from cupping and holding water.  



Right now I have a big piece right in the middle of each panel.



Am I OK doing it this way and using this material as a spacer or do I need to make the pieces small and scatter them?  Or something else altogether?

I have additional items I need help deciding too:

a:  Which way to orient the panels (A, B or C)


A.  Cross wise close to vent and not covering the access hatch in the back (Shading)


B  Cross wise at back covering access hatch.  No shading.


C.  Front to back and again covering access hatch.  This also shows the vent pipe the wires will be going down.

I am leaning toward C for no more reason than I will have more flat surface to attach the cables to and I really don't need to open the access hatch (air conditioner access).  If I do the panels are attached by Velcro and can be moved easily.


b.  How to fasten down those cables to the roof to get over to the vent stack so they aren't flopping in the wind and drumming on the top when I go down the road or the wind blows.  I will probably put as much of the cable in that split loom stuff as I can short of the connections.  Maybe route the cables forward to the vent cover and attach to it, then over to the vent stack and attach to it (long way around)?!?  Wrap Velcro around the split loom and put the other half on the roof and just stick it down that way?!?  Decisions, decisions......

c.  I am thinking of putting these roof panels in series and they will be on a plug that I can unplug when in the shade and plug in my remote panels.  Do I need to unplug the roof panels if I connect the remote panels (also in series) in parallel with the roof panels (series)?  I am thinking of the voltage difference between the remote panel (voltage drop) and the short cable run of the roof panels especially if I am in the sun because I need the power to recharge after a heavy night of usage.  MPPT controller.

I have already cleaned the back of the panels and put the industrial strength Velcro on them.  There are two colors as I was just about out of the black and Lowe's only had the white.   One roll by itself (15 ft.) is not long enough to do both panels.

Nice purchase! I've seen a few builds that use one of the Sikaflex products to adhere and seal panels to the roof, one was even a rigid panel on brackets with no penetrations. I found that one surprising. I wish I took notes as there are many Sikaflex products and I don't remember which... http://usa.sika.com/en/home-page-features/product-finder/iframe_and_dropdown/sikaflex.html

It's hard to tell from the pictures, but it looks like your roof has a pitch. As little as 1/8" per foot is plenty to keep the water drained.

What about using pvc pipe for conduit and gluing it to roof with Sikaflex? BTW, what keeps water out of the vent stack?

I know that flexible panels get hotter because no air behind them, but are there any other drawbacks? Seems like such a great, low profile solution, especially for steath, I wonder why I don't see them more...

BradKW said:

Nice purchase!  I've seen a few builds that use one of the Sikaflex products to adhere and seal panels to the roof, one was even a rigid panel on brackets with no penetrations. I found that one  surprising. I wish I took notes as there are many Sikaflex products and I don't remember which... http://usa.sika.com/en/home-page-features/product-finder/iframe_and_dropdown/sikaflex.html

It's hard to tell from the pictures, but it looks like your roof has a pitch. As little as 1/8" per foot is plenty to keep the water drained.

What about using pvc pipe for conduit and gluing it to roof with Sikaflex? BTW, what keeps water out of the vent stack?

I know that flexible panels get hotter because no air behind them, but are there any other drawbacks? Seems like such a great, low profile solution, especially for steath, I wonder why I don't see them more...

Click to expand...

Putting the panels down with the industrial strength Velcro is a proven method and makes taking them up and putting them back easy.

The roof is curved but the access hatch cover is flat with a little bit of concave to it.  It holds water there.  I also want to space the panel up a little bit for cooling.  I will probably remove the big piece of spacer and put a lot of little ones there instead if everyone thinks the closed cell stuff will be OK.

Hotter is part of the reason for the spacers.  Drawbacks are the cost.  About twice what a rigid panel would cost.  That is probably the big reason you don't see more of them.  Also if they are mishandled at all, the solar crystals can crack.  I think this is the biggest reason you don't see more and why the cost is higher for them.  A plus is they weigh about 4 lbs each and will conform to a rounded roof as well as being very low profile.  I am not worried about stealth.

The vent stack is only a 2 inch pipe.  A 5 inch rain in a 2 inch pipe would be a negligible amount in the grey tank. Maybe a pint or quart (too lazy to do the math)?  The grey tank is 25 gallons.

I will probably go with the split loom and Velcro for the wiring.  It seems the simplest and easiest to remove not to put down trying to acquire some Sikaflex.  I have never heard of the stuff and would not know exactly what to get.  It also would probably be harder to remove once affixed.  Thanks for suggesting that.

I still need input on my remote and permanent panel wiring questions more than anything.  Any ideas/theories on this?

in my experience Velcro that is in the weather 24/7/365, will only hold up a couple of years. this is with the stuff made for outdoor use. I see where people have used it, but I have my reservations. highdesertranger

I would suspect Velcro has enough movement and permeability that cavitation might become and issue at highway speeds?

I will check it yearly when we return home for Thanksgiving and Christmas as part of a yearly inspection.  Easy enough to replace if it looks like it is starting to let go.  More frequent inspections to start with, like the first fill-up.

I use small squares of the stuff inside the Roadtrek to hold things in place. If I want to move one of the little squares, it is a PITA to un-stick and then I have to throw it away as the sticky is not as sticky anymore.  I have to pry pretty good on the things that are Velcro-ed together to get them apart.  If the panels come loose,the wiring will have them dangling on the side being held by the wires at which point I can disconnect the MC4 connectors and store the panels if they aren't damaged beyond repair.  I will rethink this if a problem arises.  I just don't want to put down some type of "glue" or screw them down that will be very difficult to remove/patch later if the need arises.  Wind shear or the lifting on them from the aerodynamics is not much concern.  They are very thin so doesn't present much frontal area and pulling straight up on this Velcro is stronger than what I can pull, on larger pieces.

If you have a method that doesn't require a hard to remove glue or drilling holes in the roof, I am all ears.

Since there seemed to be no other alternative to Velcro that did not require drilling holes in the roof or bonding them with some kind of Gorilla snot, I installed the panels on the roof today.
  
I did change my "spacers" to a bunch of two inch squares instead of one big piece.



After cleaning the roof thoroughly with Windex a couple of times again (rained this weekend), I put a panel in place and removed the end backing protecting the sticky and pulled the backing about halfway on the sides.  Propping the panel on a couple of sticks about halfway on the sides (under the backing), I positioned a panel and stuck the sticky end down.  I then removed the sticks and the other end backing and the two sides backing and stuck it in place.  Rinse, repeat for the other panel.



After letting them sit in the sun for about and hour, I pressed them into place again using the heel of my hand.  There is no way wind is going to take these panels off.  I forgot to put zip ties in the corner grommets at the front before I got the panels installed    So I had to pry up the corners to punch a hole in the Velcro to put the zip ties in.  This was no small task as the velcro itself is stout and the sticky where it was stuck to the roof was not going to let go.  I will check it yearly for adhesion during annual inspection.  I will not be checking it again until next year.

I have the cables routed down my grey tank vent and out of the vent inside the closet.  I routed the cables beside the vent pipe all the way to the floor of the closet.  Under the floor is my Progressive Dynamics power center.  I re-installed the cover over the vent pipe in the top of the closet.  

Tomorrow, I will drill two holes from this space under the closet into my storage bay where the solar charger is installed and connect the plug so it will plug into the solar charger.  Then it is just a matter of putting the floor back in the closet and replacing the vent pipe cover in the bottom portion of the closet.

Setup of the Midnite Kid on another day.

My two portable panels still need to be wired and will probably wait until I get to the RTR.  I am going to bring some material to the RTR and see if there is someone that brought a sewing machine :dodgy:  I want a slip cover for them (like a pillow case with a fold over flap) to make storage/deployment easier.  I will pay a reasonable fee for this if anyone is willing.  I will make a request at announcements if Bob will let me.

Looks clean! Almost looks like you could have fit all 4 up there...guess you would've if could've?

BradKW said:

Looks clean! Almost looks like you could have fit all 4 up there...guess you would've if could've?

Click to expand...

I could have fit three if I moved these two back further and turned one sideways behind the vent.  They would have to be connected in parallel if I did that.  That also defeats my purpose of having two portable panels to put in the sun if I am parked in the shade or I need to add additional capacity because we aren't conserving

nice looking install. highdesertranger