5 Panels for RV rooftop - first time buyer with questions

[Boondock Saint]

Hello,

Which of the 3 panels would you go with for an installation on an RV where the panel will slightly exceed the curve edge of the roof?

I have a 30' Jayco Greyhawk and after playing solar tetris for ages, I've determined the best I can do is 5 panels. There is about 39.5" from the AC and vents to the edge of the RV, so I can't exceed that distance by too much. All panels will fit lengthwise.

I'll be supplying these to one or two SCC - probably some form of S/P depending on what and how many SCC I decide.


The smallest that fits is the Trina Solar TSM-410-DE15H > 410 Watt Mono Solar Panel = 79.69" x 39.53" x 1.38" / 5*410 = 2,050w

The next two are larger, equal size and more watts:

LONGi LR4-72HPH-445M > 445 Watt Mono Solar Panel = 82.44" x 40.71" x 1.38" / 5*445 = 2,225w

LONGi LR4-72HBD-440M Hi-MO4 BiFacial 440 Watt Mono PERC Module = 82.44" x 40.8" x 1.37" / 5*440 = 2,200w

Thanks in advance for your considerations, I look forward to hearing from you.

[chrisski]

Really sounds like all of them will hang over the edge.

Do you know specifically the hardware and how you’re going to mount them? Most panels ask for some space to allow for expansion, I think 1/4” between objects.

I’d counter with go to a place that sells cheap solar panels, like perhaps San Tan Solar, see what’s in stock. A smaller panel may fit the jigsaw bettter.

My last panel installation on my RV,I was on the roof with cardboard cutouts. I had some that came close to the edge, that I decided not to go with.

If those are your only options, I’d figure output of each panel per area, square foot or inch, and if those are suspiciously stronger than the other, I’d play close attention to all the reviews on E-Bay or Amazon or wherever yo buy them. Honestly though, with 950 watts of panels on my roof of my 35’ RV, I have more than enough charging power for anything short of Air Conditioning, and unless you’re running AC, I don’t see a huge difference in any of those panels. I don’t think 2000 - 2200 watts on yours produces enough power to run an air conditioning unit, at east not a 20 amp, 110 v unit I have on top of mine.

With 950 watts of panels, I can be done charging most days by 10 am. I do have 400 watts of ground panels, but I have not deployed those recently.

[Boondock Saint]

As a follow up here. I've purchased the rest of the solar equipment. The only outstanding major purchase left is the panels.

I have 32 EVE 280AH cells for a 560AH 2P/16S 48v battery with 28.8KWH. I plan to use this huge bank and continually pay it forward for times I won't have much or any solar, or shore power.

The Quattro 48v 5K will power the A/C from this bank. I can program it to auto start the generator if the battery voltage goes down to a threshold.

I'm after the most watts I can get on the roof, and as if this post it still looks the the first two panels in my list - the Trina and the Longi.

I like the specs and reputation of the Panasonics, but they are more expensive and not as many watts in the size and form factor I need.

[Boondock Saint]

I bought 5 of the Trina 410w panels.

For the inner roof mounting of these 80" panels, I could use 4 Renogy Solar Panel Mounting Z Bracket Mounts per panel inside, set on top of flat aluminum strip drilled into my roof with the double sided Eterna-bond type materials the entire length.

On the outside of the panels I would use a set of 4 Heavy Duty Z-Style Mounting Brackets per panel outside, offsetting the distance from the outer flat aluminum strip as above. This might leave a slight lean of the panels towards the outer edge of the RV, which is a good thing to vacate water and dirt. This will be 8 mounts along the lengths of the panels and reinforced with short bars on the inside lip of the panels for extra strength.

This seems simple and inexpensive. I could use strut in place of the flat aluminum bar, but I don't think I need to.

Thoughts?

[Mike90250]

BiFacial is wasted on a RV roof, no light from behind.

I don't know the voltages of the panels, but 5, is going to cause headache. you likely need 2 panels in series to get enough voltage to charge that 48V bank, 5 in series is going to likely overvoltage your charge controller. 4 panels wires 2s2p is going to be closer to the right solution than 5.

[Boondock Saint]

Thank you. Which charge controller are you referring to? The Victron I spec'd for three panels or the Victron I spec'd for two panels? Or the Victron for the DC-DC step up from the alternator?

As stated in post #4, I've already purchased and rightsized the SCC's for both runs and this is not part of the ask here.

After all this time from my first post 05-10-2021 when I needed PANEL buying guidance, no one stepped up but our friend Chisski. Now that I've made the purchase and ask for sound opinion about mounting, you only reply to my fist post.

At this time I'm looking for some feedback from people who work in the industry and have mounted panels on fiberglass roofs traveling at highways speeds+.

Any RV DIY people around here?


.

[Mike90250]

Other than mentioning SCC's, I don't see anything. But go on ahead and buy stuff, no cost out of my pocket.

[J.P.M.]

Thank you. Which charge controller are you referring to? The Victron I spec'd for three panels or the Victron I spec'd for two panels? Or the Victron for the DC-DC step up from the alternator?

As stated in post #4, I've already purchased and rightsized the SCC's for both runs and this is not part of the ask here.

After all this time from my first post 05-10-2021 when I needed PANEL buying guidance, no one stepped up but our friend Chisski. Now that I've made the purchase and ask for sound opinion about mounting, you only reply to my fist post.

At this time I'm looking for some feedback from people who work in the industry and have mounted panels on fiberglass roofs traveling at highways speeds+.

Any RV DIY people around here?


.

I'd try an RV forum.