Mounting Solar Panel on curved roof

[Dave Nathanson]

Hi, I'm gearing up to upgrade my 5 watt solar panel with a 100 watt panel so I can run an Engle Fridge Freezer (future purchase). Some of the places we go, ice is just not readily available. You can see the old 5 watt panel on the left side of the photo. The question is how to mount the new panel. I have found a "narrow" panel, the Renogy RNG-100D is 47"x21.3". Square panels are way too big because I already have a roof vent & roof rack. My TD is 5 feet wide, so that 47" panel will easily fit mounted sideways. The tricky part is how to mount the panel onto a curved roof. So as usual, we built it with cardboard first!

I'm figuring that some simple angle bracket across the front edge of the panel will be fine, but the back is 5" above the curved roof. So I'm interested in mounting suggestions for that. Maybe just make up several 2" wide verticals. I'd like to re-use some of the Hurricane Hinge screw holes, that's where the solid wood is. The rest of the roof is um, I forget, but I think it is 3/16 plywood & aluminum sheet. But there is also some frame around the roof vent. And the old solar panel is flat mounted through the roof, which has never been a problem, but it's also low, not 5" above the roof.

Anyway, I'm open for your mounting suggestions.

Best,
Dave Nathanson

[Shadow Catcher]

Unless you have a high voltage panel any shading i.e. the vent will cause a loss. Were it me I would use aluminum angel VHB taped to the roof (all the way across) and then use an aluminum riser to bolt to the panel.

[Esteban]

Dave,

Grape Solar www.grapesolar.com has flexible solar panels with 15, 30, 50 or 100 watts. grapesolar.com/small-off-grid-manuals/PhotoFlex-100W.pdf. They are sold by Costco, Lowes, Home Depot, and some others. www.homedepot.com/Grape-Solar-PhotoFlex-100-Watt-Monocrystalline-Solar-Panel has the 100 watt photoflex for $298.00. Pricy - yes. Upside - it's flexible, weighs 3 pounds, is 41.34" long, 21.26" wide and .12" tall...so it can fit on just about any teardrop roof and/or hatch.

You might have room for several!

BTW, look in Camping Secrets for Truckfridge AC/DC portable refrigerator/freezer where I went overboard with links and YouTubes for many brands of chest type fridge/freezers. If you buy a TruckFridge instead of an Engel it may save you enough $$ to buy a Photoflex 100 watt panel.


Dave, could you relocate your roof rack between the galley hatch and the fan lid? Then mount a flexible solar panel in front where the roof rack is now? It might fit better there and be well away from shading when you put up a shade cover over the galley hatch area.

[bdosborn]

I made a tilting bracket for the teardrop, using aluminum angle from the home center and a couple of hinges.



Then I used some channel to span the roof as I didn't want to drill any holes except in the edge trim



You can follow the curve of the trailer for a bit and it doesn't look too bad:



Given that you have an off road trailer, you might want to research the VHB tape and traditional framed panels . It's worked on my flat panels but I don't bounce my trailer around like you do.

I've got some high efficiency flexible panels from eBay (that look suspiciously like the Grape solar but $100 cheaper) that would follow the curve of your trailer quite well.


eBay Linky

They don't have as good off axis performance as my framed panels so I don't get as much energy out of them as I'd hoped, about 20% less laying flat.

Install Thread

Bruce

[Esteban]

Bruce's ebay link led to additional choices like this one Semi-Flexible-135-Watt-Solar-Panel-High-Efficiency-Sunpower with a 135 watt rating for $275.00. It is approx. 21" x 58" and it can take up to a 30% bend. It would seem to (just barely) fit on Dave's roof. The ad claims it is (up to) 21% efficient.


OR

you might try to sand/reshape the base of solar corner mounts to better fit rigid solar panels to your roof.

OR

use adjustable mounts www.amsolar.com/35mm_rocker_foot_mount_set