Dual Solar Panels on a 21

[Ron in BC]

Originally Posted by SFDavis50

I assume your panels have an inch or more of space between them and the roof so air can circulate and they shade the roof.

My panel is in its' "down" position but still has more air space for circulation than if it was mounted on the roof.

I guess what surprised me was that the white bottom surface was hotter than the black top surface.

Ron

[cpaharley2008]

I wonder why Escape 19 owners do not mount auxiliary panels on the front window panel, it is always open while camping and would still capture some while closed. That would be my first place to mount an extra panel.

[Donna D.]

Originally Posted by cpaharley2008

I wonder why Escape 19 owners do not mount auxiliary panels on the front window panel, it is always open while camping and would still capture some while closed. That would be my first place to mount an extra panel.

Weight on the hinge may be a concern, along with the heat generated by the solar panel. It really should have some airspace behind it.

[cpaharley2008]

I was thinking of the lightweight, flexible panels like these https://www.amazon.com/HQST-Monocrys...e+Solar+Panels
about 4 lbs and heat would dissipate while open.

[Jim Bennett]

Originally Posted by padlin

Found this list of pros and cons on the flexible panels in the Wynn's RV blog. Flexible RV Solar Issues Revealed - Our One Year Review

Good to get a review from a user. The main concern I would have is the cupping effect, something to bring up with the supplier should I continue to research this avenue.

The issue of not tilting is valid, but even if I had the capacity, I do wonder how much I would bother to use it.

Still thinking...................

[AK snowbiker]

Every couple of years I revisit the mounting flexible solar panels. I wonder if using the wide industrial hook and loop strips (Velcro) glued to the shell and panel would work. You would a small air gap for the heating issues and you would be able to move the panel if necessary. Scott

Scott and Lori
I like bikes!

[gbaglo]

On sale again at Canadian Tire this weekend. This is the best price I've ever seen. You will probably have to buy a hub to use them together with one controller ( appears to come with two ).

[Patandlinda]

Originally Posted by Ron in BC

I'm not sure what brand my friend's panels are but they're the kind that are semi rigid plastic, not the really flexible rubber kind. He made a very lightweight frame for them out of aluminum angle so that he could attach brackets to them etc. He's up the coast right now without very good cell coverage but I was going to get the website info for them when he returns.

Ron

Pat

[Ron in BC]

Originally Posted by Jim Bennett

The issue of not tilting is valid, but even if I had the capacity, I do wonder how much I would bother to use it.

My panel was in the down position the whole Olympic Pen. trip. Overcast days and shaded campsites. Didn't switch to #2 battery at any time and the battery was always fully charged, which is a roundabout way of saying that even in the fixed lower position and not tilting it, it's still pretty effective.

Originally Posted by Donna D.

Weight on the hinge may be a concern, along with the heat generated by the solar panel. It really should have some airspace behind it.

Yep, from the temperature recorded under my panel it'd probably melt the plastic window cover. Unfortunately the panel isn't quite the right size to permit removing the plastic and installing the panel in its' place.

Ron

[Ron in BC]

Originally Posted by cpaharley2008

I was thinking of the lightweight, flexible panels like these https://www.amazon.com/HQST-Monocrys...e+Solar+Panels
about 4 lbs and heat would dissipate while open.

Those are very similar to the ones my friend bought earlier this summer. My next one will be that type. I don't need the flexibility but the lightweight will be nice seeing as though I have a penchant for hoisting and tilting my panels.

Ron

[padlin]

Originally Posted by Old Skool

Every couple of years I revisit the mounting flexible solar panels. I wonder if using the wide industrial hook and loop strips (Velcro) glued to the shell and panel would work. You would a small air gap for the heating issues and you would be able to move the panel if necessary. Scott

Scott and Lori
I like bikes!

Not a bad idea, 3M's Dual Lock would probably do the trick, if you determine the best adhesive to for the panel and the gelcoat.

Don't know how it'd be to pull apart the 2 strips of HD Dual Lock? not much to grab onto on the solar panel.

[tractors1]

Figure out how to replace awning fabric with flexible solar material and you could just roll out as much as you thing you need. Probably wouldn't even need to tilt it!

[stephen99]

Originally Posted by tractors1

Figure out how to replace awning fabric with flexible solar material and you could just roll out as much as you thing you need. Probably wouldn't even need to tilt it!

Eventually this will probably happen.

[Jim Bennett]

Originally Posted by tractors1

Figure out how to replace awning fabric with flexible solar material and you could just roll out as much as you thing you need. Probably wouldn't even need to tilt it!

Originally Posted by stephen99

Eventually this will probably happen.

I don't doubt it at all. I truly believe solar is the best alternate to fossil fuels for energy. I remember reading an article about how they are working it into road surfaces. I don't think a fabric like Charlie suggest is all that far out.

[tractors1]

A Scottish company and (of course) the Chinese are working on the textile approach. Meanwhile, there are roll-up collectors on the market: R60 60 Watt Rollable Solar Panel - PowerFilm Solar

[SFDavis50]

Originally Posted by SFDavis50

I assume your panels have an inch or more of space between them and the roof so air can circulate and they shade the roof.
51 C (123.8 F) is pretty hot; in Arizona or Texas it would be a lot hotter. If mounted directly to the roof surface they would radiate a lot of heat into the trailer which may be good in winter but bad in the summer.
I don't know if the flexible types generate more or less heat but perhaps you could make window awnings for use in the summer then strap them to the roof in the winter.

I have read on other forums that the cupping of the flexible panels bonded to the top of an RV is caused by the extreme heat and the inability to dissipate that heat. I suspect this is more common when bonded to an "other than aluminum" roof. Lots of people bond them to the top of Airstream trailers but aluminum is a very efficient heat sink and will dissipate the heat very well. Still, the Airstream itself gets pretty hot in direct sunlight and the efficiency of the panels decreases with heat.

Fiberglass is not a good thermal conductor so it won't dissipate the heat like aluminum. Heat from the panels will radiate directly thru the fiberglass into the insulation. Reflectix will radiate some of it back to the panel but it could also get hot enough to damage the insulation. You won't know until after it occurs.

The white gelcoat reflects very well and doesn't get hot in direct sunlight. Touch a white car and then any other colored car on a sunny day and there is a big difference.

Mounting with Velcro is an interesting idea but it would have to be done so that there is no way the panel could melt or soften the plastic hooks on a worst case summer day in Texas or Arizona. Mounting the flex panels onto an aluminum sheet but still having it above the surface of the trailer could be more aerodynamic than the current panels but I wouldn't bond them to the fiberglass surface, although in winter this may be an interesting way to add some heat.

Fiberglass sailplanes are white and the only areas which get painted other colors are non structural areas. The reason is that the fiberglass becomes more flexible as it get hotter. If you paint stripes or numbers on top of the wing the area under will get much hotter, more flexible and will bend more under stress. One wing bending more than the other can flip it.

[gbaglo]

I have my Sirius antenna ( weighs maybe two ounces ) mounted to the dash in the car with Velcro. The Velcro migrates across the dash from sun and heat melting the adhesive. I'd never use Velcro to mount a panel.

[AK snowbiker]

Originally Posted by gbaglo

I have my Sirius antenna ( weighs maybe two ounces ) mounted to the dash in the car with Velcro. The Velcro migrates across the dash from sun and heat melting the adhesive. I'd never use Velcro to mount a panel.

I know the heavy duty stuff that we used in our vehicles overseas in a hot, dusty environment didn’t move at all. But I agree, every now and then when I revisit mounting flexible panels I always come to the conclusion that the fixed solid panels are still the way to go. Scott

Scott and Lori
I like bikes!

[Losangeles]

I'm just excited to get dual solar panels at build! I was not sure it was possible. it is, as long as no tv antenna or other added stuff in the way.

[Brian B-P]

Originally Posted by gbaglo

I have my Sirius antenna ( weighs maybe two ounces ) mounted to the dash in the car with Velcro. The Velcro migrates across the dash from sun and heat melting the adhesive. I'd never use Velcro to mount a panel.

The problem in this case is not the Velcro (or other hook-and-loop fastener, if it's not really Velcro®), but the adhesive, right?

With a flexible solar panel there is the same issue of getting the right adhesive, plus hook-and-loop fasteners only work well on fabric, because they are designed to peel apart and hold under shear (not tension perpendicular to the plane of the fastener) - I would not want to use this stuff with bendable solar panel. I think Velcro and similar fasteners make great closures for flaps on jackets, and a lousy solution for just about any mounting problem not involving fabric.