Eurovan Camper mods

DIY SunPower Flex 110 Solar Panel Custom Mount

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Updated 2021-05-18 : First version.
Updated 2022-07-03 : More detail pictures and instructions for adding M6 T-Knobs for extra security

Introduction

In 2011, I installed a 85w solar panel. In Spring 2021, I followed this up with a major renovation of the Eurovan Camper's 12V system, which included a new solar panel.

Goals for the new solar panel:

• compatible: if the panel has about the same Voc and Vmp as the existing panel, they can be wired in parallel to the SCC (solar charge controller)
• light weight: I'm concerned about too much weight attached to the Eurovan's roof. There have been reports of the Winnebago roof cracking due to stress. Lighter is better. The existing panel, plus mounting brackets weighs about 22 lbs (10 kg)
• efficient: a high wattage per area, since space on the Eurovan roof is limited.
• safe: I've seen reports of cheap solar panels catching fire
• portable: ability to dismount the solar panel from the roof to catch early or late off-angle sun, or to catch sun while the van is parked in shade
• reversible: no new holes drilled in the roof; nothing glued to the roof
• cool: solar panels are more efficient when they stay cool, so a frame that provides an air gap was desired.

Solution

• A SunPower 110 flexible solar panel: light weight, powerful, and made by a hiqh-quality manufacturer
• A custom aluminum roof mount: light weight, allows the flexible panel to be securely mounted, but easily slides out for alternative placement. Keeps the solar panel from touching the roof, so it can stay cool.
• The panel weighs about 4.5 lbs, and the rack is about 6.5 lbs, for a total weight of 11lbs. By comparison, a glass 100W solar panel weighs 14+ lbs (without a mount)
• Note: the Eurovan roof is slightly curved, and highest in the middle. The mount needs to keep the panel at least 1.5" above the roofline at either side, to avoid contacting the roof in the middle.

Parts:

• SunPower 110 Flexible Solar panel
  Note: there's a 100W version of this solar panel which would work just fine and is slightly cheaper.
• Aluminum Square Tube: 3/4" x 1/16" x 48" (quantity 5)
• Aluminum Angle: 2" x 1/16" x 96" (quantity 1)
  Note: You only need about 48" of this, but it's sold in 96" pieces. This is what mounts the frame to the Yakima rack.
• Aluminum Angle: 3/4" x 1/16" x 96" (quantity 1).
  Note: this is what forms the slot that the solar panel slides into.
• 3M Super Strength Molding Tape 1/2" wide x 15' long
  Note: 15' (about 5 meters) is barely enough - better to buy at least 20' length
  Note: use this on all connections - not only does it help hold the pieces together while you assemble it, it provides great strength and vibration damping
• M6 stainless internal hex ("Allen") bolts: 30mm length for the frame (quantity 12) and 14mm for attaching to the Yakima rack (quantity 4)
• M6 stainless nylon lock nuts (quantity 12)
• Steel shelf brackets 1/2" to 3/4" size (quantity 4)
• M6 rivNuts (rivet nuts) (quantity 4)
• M6 t-knobs (quantity 4). These are easy to unscrew by hand. If you are worried about theft, you could use some sort of M6 sized security bit instead.

Tools:

• Saw to cut aluminum, such as a chop saw, table saw, hack saw, etc.
• Drill and drill bits
• (optional) Rivet Nut installer tool (such as Astro Pneumatic 1442): to enable M6 t-knobs at each of the 4 corners.

Step-by-Step:

(click each picture for full size)

1. Measure Parts Carefully!
   The solar panel will just barely slide into the mount when this is done, so you need to measure the dimensions carefully before starting.
   Although most of the aluminum bar stock is actual size (3/4" is exactly 0.75 inch), you will be adding some 3M mounting tape, so keep that in mind
   In my first attempt, I actually made the mount about 1/8" too narrow. Fortunately, the solar panel itself is soft plastic, so I was able to trim it with a sharp knife to fit.
   
   



2. Right View
   Shows the right side of the mount, before adding the "L" bracket keepers. Be sure to put 3M mounting tape between all connections. (Be careful: 3M tape is very strong. If you make a mistake, you can pry the parts apart, but it takes a big pry bar and lots of patience, and it's easy to damage the aluminum )
   
   
   
   



3. Side View
   Detail view showing the Left side, before adding the "L" bracket keepers. Notice that the overall thick L bracket is 2" tall, and there are two layers of 3/4" square tubing (plus some 3M mounting tape) which leaves just the right amount of lip left over.
   
   
   
   



4. Top View
   Shows how the shelf bracket, M6 internal hex bolts, and M6 nylon lock washers go together.
   
   
   
   
   



5. M6 internal hex bolts, washers and nylon lock nut
   I could not find these at Home Depot, but the local Ace Hardware had a great selection
   M6 stainless x 30mm, plus two washers, and a M6 nylon lock nut. You may need more M6 (shorter) to connect to the Yakima roof rack, also.
   Hint: the M6 takes a 5mm Allen key
   
   
   
   



6. (almost) Finished Mount bolted to Yakima Rack on Eurovan Roof
   The mount is connected (also using M6 stainless internal hex bolts) to the Yakima rack.
   The solar panel has yet to be inserted.
   Notice the circles in the 4 corners: these are where the M6 rivNuts will go (see Steps 10, 11, and 12 below)
   
   
   
   



7. Inserting the Solar Panel
   
   To insert, one simply slides the panel in from the left side.
   
   
   



8. Mounted on Van
   The finished mount is connected (also using M6 stainless internal hex bolts) to the Yakima rack.
   The solar panel is held in place mainly by the 2 side rails, as well as (not visible) velcro under the edge.
   To remove, one simply lifts the edge up (detaching the velcro) and then slides the entire panel to the left off the van.
   
   
   



9. New vs Old Solar Panel Mounts
   The old panel is non-removable, weighs over 20 lbs, and is rated for 85 watts.
   The new panel is easy to remove, weighs 11 lbs (panel + mount) and is rated for 110 watts.
   
   
   



10. Securing the Panel with M6 RivNuts
    The new panel is flexible, so it's important to make sure it doesn't fly off in heavy winds (ask me how I know about this risk!).
    The solution is to add M6 t-knobs at each corner, which screw into a M6 sized RivNut (Rivet Nut)
    
    
    
    
    



11. M6 T-knobs
    You can find M6 T-knobs at your local True Value hardware store.
    
    
    
    
    



12. Secure with M6 T-Knobs at each corner
    Showing the M6 T-knobs installed. The branch and leaves are where I scraped into some foliage. It's good to remember that wind is not the only thing that wants to damage your solar panels.