Solar Panel Mounting

[kernwig]

Welp, I was temped by the SunPower brand but I want to put panels in parallel on front and back of my 21C to catch different sun angles. The positions have different amounts of space available. Each SunPower size has different voltage ratings through, so they don't mix efficiently.

[Brian B-P]

Originally Posted by kernwig

Each SunPower size has different voltage ratings through, so they don't mix efficiently.

If they have the same current rating, and you are willing to use an MPPT controller, you could connect those panels in series... but that's not ideal. You could also use separate controllers (even if the current ratings are different), but if the panel voltages are sigificantly different at least one of them must not be suitable for the battery, so that one is either too low to be useful or high enough to need an MPPT controller.

Update:
According to the specs I've just found from SunPower, the 50-watt (SPR-E-Flex-50) and 100-watt (SPR-E-Flex-100) panels have the same peak-power voltage, and the 110-watt (SPR-E-Flex-110) is so close that it should just run as a 100-watt panel if tied to one of the 50-watt or 100-watt panels. The 170-watt panels are nearly double the voltage of the others, intended for nominally 24-volt systems.

[tdf-texas]

Originally Posted by rubicon327

If the Lensun panels are that much I wonder what people think of the flexible SunPower panels? They are supposedly very high quality and used a lot on boats. 110W for $179 right now.
https://www.amazon.com/SUNPOWER-Port..._t1_B07C34GHGV

Sunpower solar cells can be some of the best available. But... Sunpower solar cell grades range from Grade A to L. You would think Grade A would be the highest grade, but, in fact, it's the lowest grade. The highest grade is Grade L.

Here's the "but" part. Sunpower doesn't always use the high grade cells in their consumer products. Some of the panels are made in China and they use the cheap low grade cells. I would ask what grade was used in the panel I'm interested in buying and go from there.

https://www.flexible-solar-panel.com...the-top-grade/

Lensun uses high grade cells - that may be the reason some of us are having good success with them.

[Patandlinda]

Originally Posted by tdf-texas

Sunpower solar cells can be some of the best available. But... Sunpower solar cell grades range from Grade A to L. You would think Grade A would be the highest grade, but, in fact, it's the lowest grade. The highest grade is Grade L.

Here's the "but" part. Sunpower doesn't always use the high grade cells in their consumer products. Some of the panels are made in China and they use the cheap low grade cells. I would ask what grade was used in the panel I'm interested in buying and go from there.

https://www.flexible-solar-panel.com...the-top-grade/

Lensun uses high grade cells - that may be the reason some of us are having good success with them.

Following this thread Tom and so glad we went with Lensun ! Pat

[MyronL]

Front roof of trailer is not my choice for installing that flexible Lensun solar panel but... just measured there and it is an area that, being 41x31 inches, should accommodate the 120w panel. Transmission lines may be routable in through the Maxifan, I think. Or not. Have to get in there and investigate that. A line continuing inside and down the wall to the drivers side dinette might be the big problem.

[HABBERDABBER]

Last Winter I bought a Lensun 100W portable. In March I wired it up for my rig and noticed these "bumps" or de-lamination at 1st time of use. I don't believe they were there to begin with.

Lensun sent another panel and didn't want the wonky one back. The customer service was very good in response time and info. They said .01% of panels experience this problem.


The de-lamination has increased and is localized and it appears to be internal "shorting" as the bump areas are hotter than other areas.


This panel was working OK this summer.


Lensun was prompt and provided good service, but their panels have issues, just like any product.

[Mark B1]

Originally Posted by MyronL

Front roof of trailer is not my choice for installing that flexible Lensun solar panel but... just measured there and it is an area that, being 41x31 inches, should accommodate the 120w panel. Transmission lines may be routable in through the Maxifan, I think. Or not. Have to get in there and investigate that. A line continuing inside and down the wall to the drivers side dinette might be the big problem.

Note that although the Lenson panels are flexible it is only in one plane and they are not really made for compound curves. There is a slight crown on my trailer from side to side and then there is the more pronounced curve longitudinally at the front and back. I kept my panels as much away from the ends of the trailer as reasonable for this reason. You may want to cut a template from stiff cardboard and see how a flat panel will actually lie in your chosen area. My two concerns where compound bends stressing the panel, and waviness along the edges which would be harder to bond with the 3M VHB tape I used. Eternabond tape would likely still work though. I would avoid the area if you find a compound curve.

[alanmalk]

Originally Posted by kernwig

...

- They don't all have the same voltage output. If you wire panels in parallel, you only get the voltage of the lowest one.
...

Arrgggg. I cringe whenever someone says that.

I tried an extreme mix in my backyard. The so-called "pull-down effect" is a myth.

See my results in thread "Experiments with solar panels" on this website, mixed a 6V panel with a 12V panel.

I will admit that there is no particular reason to mix odd-ball panels unless the reasons are for something like cost or fitment. But its not the end of life as we know it.

--
Alan

[rubicon327]

Originally Posted by alanmalk

See my results in thread "Experiments with solar panels" on this website, mixed a 6V panel with a 12V panel.

https://www.escapeforum.org/forums/f...nels-4775.html

[rubicon327]

Originally Posted by MyronL

Front roof of trailer is not my choice for installing that flexible Lensun solar panel but... just measured there and it is an area that, being 41x31 inches, should accommodate the 120w panel. Transmission lines may be routable in through the Maxifan, I think. Or not. Have to get in there and investigate that. A line continuing inside and down the wall to the drivers side dinette might be the big problem.

Myron: If you are at the front with a panel why not a strategically placed cable entry port on the roof right over the side cabinet? That puts your wire inside the cabinet and then easily routed down the front corner into the dinette bench area.

[Centex]

Originally Posted by rubicon327

Myron: If you are at the front with a panel why not a strategically placed cable entry port on the roof right over the side cabinet? That puts your wire inside the cabinet and then easily routed down the front corner into the dinette bench area.

I'm with Dave on this one, Myron .... 'gird up', grab a tube of Dicor sealant, and drill that hole !

[rubicon327]

Originally Posted by Centex

I'm with Dave on this one, Myron .... 'gird up', grab a tube of Dicor sealant, and drill that hole !

I clearly have no problem with holes...added bath window, range hood exhaust outlet, passenger side spray port, exterior 12V outlet, battery box vent, holes in floor for mini-split conduit and refrigerant lines. Two more on the horizon are cable entry port for solar and an additional water inlet for my upcoming “boondocking inlet pump system” for which I’ll post the design thoughts soon.

[rubicon327]

Originally Posted by Mark B1

I don't think they will fit. I installed 3 80w Lenson panels on my 2019 Escape 19 and they just fit the width of the top (raised) section of the roof at 37" long. I could not go any wider. The 120W at 41.7 inches would not fit my trailer. It looks like you have the first gen trailer and I don't think the top section is any wider. You can see how mine fit in this photo;
Attachment 52971

Just wondering if these narrow (14") Lensun panels might fit front-to-back on the area between the raised roof section and the edge on the passengers side? That could potentially add another 165W-220W depending on if you could fit 3 or 4.
https://www.lensunsolar.com/Flexible...product_id=384

[MyronL]

Nope. Not on mine. Looking like if I want 120 watts of roof solar will just have to wait until they make one that fits. I really want just one panel and don't want to tape one down to the front of the trailer roof.

Yes, drilling a hole there does make routing down to under the driver dinette much easier. I could do it - push comes to shove. Just not there yet.

[rubicon327]

Originally Posted by MyronL

Nope. Not on mine. Looking like if I want 120 watts of roof solar will just have to wait until they make one that fits. I really want just one panel and don't want to tape one down to the front of the trailer roof.

Myron: If you look on the Lensun website they have made custom size panels for people. Maybe you could inquire about what you need and see what they say.

[Mark B1]

Originally Posted by rubicon327

Just wondering if these narrow (14") Lensun panels might fit front-to-back on the area between the raised roof section and the edge on the passengers side? That could potentially add another 165W-220W depending on if you could fit 3 or 4.
https://www.lensunsolar.com/Flexible...product_id=384

They might on some models. I know these are flexible panels but they are a little stiff and I would not want to get too close to the tighter part of the radius at the front and back of the roof. I would say if you make a template out of 1/8" plywood and it would make the bend, then the Lenson panels will too.

[kernwig]

I've run across a couple other mounting options. I like that they both make the panels removable and provide an air gap under them. I don't like having a "collect dirt" gap under them though, or the added complexity.

This one uses the SunPower panels that someone else mentioned earlier in this thread. The author basically builds a flat mount for the panels and uses the grommets to hold them on. His roof is flat - flexible panels were just used for the weight advantage.

This installation is very curved and attached by Velcro! I'm a bit more temped by this one.

I'm still leaning toward just laying Lensun panels (with FG backing) down directly and holding with Eternabond. Simple and proven by y'all. Thermal air gap and easier replacement still tempts me though.

I started setting up my solar controller and installed the port for the portable solar panel today. It's slow going getting parts during a pandemic. Just realized I forgot about some wiring - so two week wait to get that.

[ColoradoSwany]

Originally Posted by kernwig

I've run across a couple other mounting options. I like that they both make the panels removable and provide an air gap under them. I don't like having a "collect dirt" gap under them though, or the added complexity.

This one uses the SunPower panels that someone else mentioned earlier in this thread. The author basically builds a flat mount for the panels and uses the grommets to hold them on. His roof is flat - flexible panels were just used for the weight advantage.

This installation is very curved and attached by Velcro! I'm a bit more temped by this one.

I'm still leaning toward just laying Lensun panels (with FG backing) down directly and holding with Eternabond. Simple and proven by y'all. Thermal air gap and easier replacement still tempts me though.

I started setting up my solar controller and installed the port for the portable solar panel today. It's slow going getting parts during a pandemic. Just realized I forgot about some wiring - so two week wait to get that.

Adam,

I installed 3 Lensun panels with corrugated plastic sheets between my Escape and the panels. Here is a link to the string about how my installation evolved: https://www.escapeforum.org/forums/f...ons-17711.html

[kernwig]

Thanks. I do think I want to tape all around to keep water and dirt out from under where I can't wash and wax. My only thought would be to put some plaskolite under the panel first to prevent thermal transfer to the trailer, but in your thread Panandlinda said that the panel's fiberglass backing is about 1/4" and I know several others are attaching these panels directly.

I did learn from your posts though, so thank you for the link.

[sherminator]

Originally Posted by Mark B1

Note that although the Lenson panels are flexible it is only in one plane and they are not really made for compound curves. There is a slight crown on my trailer from side to side and then there is the more pronounced curve longitudinally at the front and back. I kept my panels as much away from the ends of the trailer as reasonable for this reason. You may want to cut a template from stiff cardboard and see how a flat panel will actually lie in your chosen area. My two concerns where compound bends stressing the panel, and waviness along the edges which would be harder to bond with the 3M VHB tape I used. Eternabond tape would likely still work though. I would avoid the area if you find a compound curve.

I will echo MarkB1's comment about the flexible panel being more flexible on one axis. I received my 120W panel today and threw it up on top of my 21NE. It will barely fit across the raised section of the roof, which is was what I expected. However, I thought I might be able to fit a 2nd panel further forward, but the curve would be crosswise on the panel, and it doesn't really flex much in that direction. In fact, I was contemplating using this one as a portable until the weather gets better for mounting it permanently, but I'm not comfortable with it being moved around a lot. I think I will stick to a rigid frame or a smaller size flexible for a portable. I'm also thinking since I'm only going to put one panel in front, and probably a panel on the rear, that I will mount them lengthwise instead of crosswise.

Here are pictures of the 120W (41.7" x 27.4") sitting on top of my trailer: