Solar Panels Wider than Roof

[RogerD]

Has anyone ever installed solar panels that were wider than your van roof?

Ideally, I want to sell my van and get a box truck. However, the gassers get poor MPG. I could get a diesel Sprinter and they get decent mpg, but don't if I want to deal with a Sprinter. 

I'm pretty much sold on getting 6 Sunpower 435 watt panels. I would put 4 on the roof and mount 2 on the side when parked. Which I could easily do with a box truck.

If I don't get a box truck, I could still do this with my Chevy Express extended, but the panels on the roof would hang over by about 10" on each side. I can easily make a rack to put them on, so doing it is not an issue.

Just curious what everyone thinks about doing it.

 

[highdesertranger]

ever plan on boondocking? back roads? forest? highdesertranger

 

[Headache]

As a previous owner of a box truck I can tell you with certainty that the box and roof are not designed for that much weight up top like that. One panel sure but not 4 of the kind you mentioned in your post. Just mounting them into what I'm assuming is an aluminum roof will require either a custom roof rack and/or strengthening the roof and sides of the box to handle the extra physics that are going to occur. On the side would be even worse. Is this a custom box you would have built?

I'm assuming you're looking at a 20 to 26 foot(or so) box because those panels are HUGE! Jimindenver has one that covers almost the entirety of his Excursions roof and I'm sure that HDR can tell you how big they are as well. If you are going to use all 4 to cover the roof of a 17 footer(or so) you're going to run into issues with sway and leakage. The flex from the weight will cause the upper roof supports and side trim to sway a lot and break the sealant that "glues" everything together.

I'm using these 200 watt panels that instead of glass are encased in some kind of polymer making them very light and there is some absorption from the back of them as well because of it. Jim has the link if you are interested.

 

[RogerD]

ever plan on boondocking?  back roads?  forest?  highdesertranger

I'm in FL now. Will eventually go west and was kind of just planning on doing the 14 day BLM hop.

I depend 100% on the internet to make my living. So I wouldn't go anywhere that doesn't have decent cell service using a booster.

 

[RogerD]

As a previous owner of a box truck I can tell you with certainty that the box and roof are not designed for that much weight up top like that.  One panel sure but not 4 of the kind you mentioned in your post.  Just mounting them into what I'm assuming is an aluminum roof will require either a custom roof rack and/or strengthening the roof and sides of the box to handle the extra physics that are going to occur.  On the side would be even worse.  Is this a custom box you would have built?

I'm assuming you're looking at a 20 to 26 foot(or so) box because those panels are HUGE!  Jimindenver has one that covers almost the entirety of his Excursions roof and I'm sure that HDR can tell you how big they are as well.  If you are going to use all 4 to cover the roof of a 17 footer(or so) you're going to run into issues with sway and leakage.  The flex from the weight will cause the upper roof supports and side trim to sway a lot and break the sealant that "glues" everything together.

I'm using these 200 watt panels that instead of glass are encased in some kind of polymer making them very light and there is some absorption from the back of them as well because of it.  Jim has the link if you are interested.

The panels are 81" x 41" and weigh 50 pounds each.

I would get a 14-15' box. Which would fit the panels.

I was not aware of the issues you speak of.  I could get steel studs and reinforce the box.

 

[Headache]

The panels are 81" x 41" and weigh 50 pounds each.

I would get a 14-15' box. Which would fit the panels.

I was not aware of the issues you speak of.  I could get steel studs and reinforce the box.

Will the box be metal or FRP?

The steel studs will also add weight adding to the sway.  If not secured in such a way that will still allow some flex while adding some strength anywhere that you've attached a fastener might break loose.  I ran into this when building walls inside my 26 footer.  The smaller the box the more top heavy it's going to be and the worse the sway will be.  And although 300 lbs may not seem like much, it becomes very important when it comes to rough roads and how top heavy you are making it.  It's made for stuff to go inside it, not on top of it.  That's a whole other side of engineering and fabrication.

 

[RogerD]

I'll only buy if it has an aluminum box

I see that a lot of the FRP boxes have that thin fiberglass roof, which would never work.

I will be building a custom rack for it and attach it using the channel at the top on the sides.

 

[Headache]

Good on you for the custom rack. I wish you the best on your build and will be reading. My box was FRP with an aluminum roof. At one time there was a mobile catering business. They took everything out but the junction box and that round commercial fan you see at restaurants. The sway was unbelievable! Removing that fan from the roof and patching the hole was the first thing I had done. It actually bent one of the ribs!

 

[Matlock]

I can't imagine a problem with an oversized solar wing fastened to the roof at 70 MPH. No problem at all, unless you were planning on actually keeping them. So, no the weight and surface area of those panels will not bode well unless you plan for and build a rack that the roof will support and panels actually fit the size of the vehicle. Now if you wanted to fasten a couple of them on the sides and hinge them to tilt up then you might be on to something.

 

[MrNoodly]

As a previous owner of a box truck I can tell you with certainty that the box and roof are not designed for that much weight up top like that. ...

Which is why commercial box truck roof racks mount to edges, at the roof-wall seam. There's usually a cast aluminum groove the racks attach to.

<a href="https://ibb.co/5YzcQb5"><img src="https://i.ibb.co/HNMgc5r/EnclUR.jpg" alt="EnclUR" border="0" /></a>

 

[RogerD]

That's what I was refering to when I said I would build a custom rack using the channel at the top on the sides