Minivan camper Roof Mounted Solar Panel

Darren

6 years ago

If you are building a minivan camper conversion, be advised that you will eventually want a roof-mounted solar panel.

I think this is a natural progression as you discover that your minivan is ideal for inconspicuous boondocking. I first used a solar panel for charging my DIY house battery and inverter system during my winter trip of 2017-2018. Previously, my house batteries charged while driving and provided enough power for 2 days without charging. But with the extended stop in the desert, I decided to add solar charging. I propped this panel up against the front bumper and it worked fine for my extended stay at the Rubber Tramp Rendevous (RTR) and other stops. However, for my 2018 summer trip, I planned on moving around more and didn’t want to deal with set up and tear down of the panel each day. A more permanent solution was needed.

If you can turn a screw, you can do this project. A full DIY how-to is located below, but to get an overview of the result of this RV solar panel project, check out the video first. Be sure to hit the subscribe button, so you can see my future and past DIY videos.

I mounted this solar panel to my 2013 Honda Odyssey, but the principals can be applied to almost any minivan. Just note that late model vans will likely have metric studs on the roof and domestic vans from the 90s may have inch studs. If you are not sure, buy a couple of sizes of metric nuts from the Lowe’s or Home Depot bulk bins and see what fits.

There is a parts list further down in this pose. This is one place where I won’t use the typical Amazon links, because some of these parts are unavailable or more expensive on Amazon. Shop around. At the time this post was written, you could buy steel channel at Lowe’s, but not the aluminum stuff. The price between the two is similar, so I used aluminum.

The Build “System”

After chatting with fellow Odyssey camper, Vantastic Odyssey on YouTube, I was convinced that I wanted to do a flexible solar panel on my minivan. However, I already had a rigid panel and I liked the idea of being able to remove the panel after an extended trip. This is less of a concern if you are traveling full-time in your van, but I use the Odyssey Camper in the offseason, to transport customers. I don’t necessarily want to explain that I sometimes “live in my van, down near the river.” In the end, I decided to mount my rigid panel using aluminum Uni-Strut. This material can be purchased with slotted holes that make it easier to adjust everything after loosely bolting it together. The top edges are folded over to make a “hook” and special hardware is available that attaches to the hooks. The Uni-Strut is more than just the “strut” itself as there is a whole family of parts designed to work as a System.

The “strut” itself. Available as a system of parts that helps you build your project without paying for custom fabrication.

Whenever I do a project like this, I try to keep in mind what will be easiest to build for people that don’t have a full complement of tools or a shop to work in. I’m lucky to have both, but with the exception of 5 holes I had to drill, no special tools are needed to build this solar panel mount. You can buy the strut in pre-cut lengths that conveniently work with a full-sized or mini-sized van. I also elected to use aluminum strut instead of steel or fiberglass because I wanted this to be corrosion resistant and light enough for solo female travelers, or smaller men, to lift by themselves. This lifestyle is about independence, so you shouldn’t need a crew everytime you want to put the panel on.

Uni-Strut has a built-in channel to run the wires to your solar charge converter.

I’m also using aluminum channel strut (uni-strut) for a roof-mounted solar hot water shower system (coming for RTR 2019) and my new bed, so this was a good opportunity to get familiar with the materials. This stuff is like an erector set and can be disassembled and reused as your needs change. The best form of recycling is re-use, as no additional energy is needed to melt things down (if you care about such things).

Getting Started–Tools

As I said, no “special” tools are needed, but you will need SOME tools. If you don’t have any tools, some of these can be found at a pawn shop. Also, any tradesman (carpenter, mechanic, electrician) will likely have these tools and can make the cuts and hole you need in about 15 min. If I was traveling full-time and trying to do this, I’d stop at a contractor’s shop and ask for help. It shouldn’t take them more than 30 min of labor to make all the cuts and holes. So here is what you’ll need:

Allen Wrenches
Tin Snips
Small Adjustable Wrench
Plastic Pry Bar (you can buy a “radio installation kit” on Ebay, or make your own pry bar)
Drill Bit

Take a close look at this $10 set of Allen wrenches. Notice how they have a ball at the end of the straight end? That’s why they cost $10 instead of $8. If you go looking for Allen keys (check the pawn shop first) buy this type. They let you get in at odd angles and are worth a couple bucks extra.

Although you can build this project with a single size of drill bit, I used a Unibit. These things are awesome as you can just push the drill in a little more if you need a bigger hole. I’ve bought a ton of these from pawn shops, so you shouldn’t have to spend more than about $10. If you carry tools on the road, it’s a great way to carry fewer things but still have the same capabilities.

Parts List:

All parts were sourced from McMaster.com or my local Ace Hardware. I’m not going to list prices because they will change over time and I don’t want to mis-lead anyone, five years from now. It cost about $125 to build the whole thing, but you can probably do better by shopping prices. Remember to consider shipping charges, which could be $30 from McMaster. However, they DO have everything you need, including the screws that I bought from Ace Hardware. Since I didn’t know EXACTLY what I’d need, I bought some stuff locally.

These items were purchased from McMaster Carr (McMaster.com). In the end, I decided that I didn’t need the centering washers, so you could actually skip these.

In addition to the parts shown in the photo (note the part numbers in the description) I purchased the following from the local hardware store. All hardware is stainless steel except for the fender washers, which weren’t available from Ace:

8x 1″ 1/4-20 Socket Head Screws (1/4-20 means the screw is 1/4″ in diameter and has 20 threads per inch)
pkg of 25 1/4″ Washers
pkg of 25 1/4″ Split Lock Washers (these keep tension on the screw, so things don’t loosen up)
pkg of 8 1/4″ Fender Washers

Note: 1/4″ hardware is close enough to M6 that you can use the two interchangeably, where washers are concerned. Of course, metric screws are different and you cannot interchange the threads. So, rather than buy M6 and 1/4″ washers, I used 1/4″ in both cases.

Project Steps

At this point, you might be wondering why I didn’t do this project as a YouTube video. I started it that way, but it was tough to hold the camera. Plus, I wanted to do this where I had my tools handy and then meant being near my garage. Unfortunately, I live near a busy road and the sound quality (even with a lapel mic) was horrible. However, I think the photos actually show more detail without having to freeze and zoom in on a video.

Step one is to mount the solar panel to the five-foot rail. I put my panel in the center of the rails, but you can adjust the position based on the sizes of your solar panel(s). The photos above show how I drilled the strut and the solar panel frame. I drilled the strut first and then placed everything on the floor using a marker to put a “dot” on the panel frame where I would drill. Note: this panel was apparently used when I purchased it (yet sold as new) and had existing holes. In other words, those aren’t my mistakes 😉

A Unibit allows you to drill the 1/4″ holes by applying pressure until the hole reaches the 1/4″ part of the bit. You can also just use a 1/4″ bit, but you’ll need a pilot hole.

I chose to put the screws through from the inside edge of the panel, but there is no reason you couldn’t put them in from the other direction. Place a lock washer either between the screw head and washer, or between the washer and nut. You do not need to put one on both sides.

Here’s how things look from the strut side.

There are a total of four screws holding the rails on. They are spaced about 1/4 of the way in from each end of the solar panel. Here’s what it looks like at this point. Set this aside in a safe place.

Step 2 is to prep the roof to receive the 3-foot Uni-Strut rails. Note that these can be longer if you want to extend your roof rack to do other things. If you just want a 24″-30″ solar panel up there, then 3 feet is enough on the Odyssey. If you have a different van, check the distance between the roof studs to make sure they will span the distance. To expose the factory roof rack mounting studs, you’ll gently pry up on the rubber strips that run down the roof.

As you lift the rubber strips, you’ll notice spots that aren’t lifting because the rubber strip is attached to the metal studs via a plastic clip. This is where you will pry up to pull the clips off of the stud. They just push on, but since you are prying at an angle, you’ll need a little pressure and patience. It’s a crapshoot whether the rubber strip will come off and leave the clip behind, or whether it will come up with the strip.

Blurry cam photo of how the clips fits into the rail. If the clip stays on the stud, you’ll need to pull it off and put it back in the rail.

In Step 3, we’ll cut the rubber strip to length. At the left side of the photo you will see that I’ve temporarily screwed one of the M6 standoffs to the roof stud. You can just see the rubber strip clip to the left of the standoff. This is where we will reattach the rubber strip after cutting it.

See that hunk of plastic on the roof? That’s the plastic piece at the rear end of the roof rail. I forgot to take a good shot of it, but essentially this piece needs to be removed before you pry the rail up. Raise the rear door and it can be detached by pulling up and toward you.

Use the standoff as a guide to mark the rubber strip/rail. Cut the rail with the tin snips and reattach it to the clip. Note that to do this you first have to make sure you didn’t bend the rail/strip. If you did, you can mold it back into shape with gentle force from a screwdriver.

In this shot, the clip stayed on the stud. Just pull it up and slide in the end of the rail as shown in the photo above.

Push the rail/clip assembly back onto the stud. That will hold things down so the rubber strip stays on from your new rack, forward to the windshield. This is what the clips look like when they are off the van. If you break or lose one, you can get new ones from your Honda dealer (or a body shop can order them).

Step 4, put the M6 standoffs on the studs. A “standoff” is simply a spacer that is threaded at both ends. In metric measurement, “M6″ means a 6mm metric thread. Place a 1/4″ flat washer on the stud, followed by a 1/4″ split washer, then the standoff. 1/4” is close enough to M6 that we can interchange the washers. That saves having to buy screw-specific washers for this project. Because these studs are painted you may have to tighten and loosen the stud as you thread it on, to scrape the paint off the threads. Tighten them down to the point that the split lock washer is compressed (the splits line up) and then a tiny bit more. Don’t over tighten or you can break the stud and then you’ll have a much bigger project. Once the Uni-strut is in place, these standoffs are not going to back themselves out, so they don’t need to be excessively tight.

Note: Many people mistakenly think that the threads on the studs are 1/4″ (I forget the thread pitch they quote) but THIS IS NOT TRUE. They are M6 and if you think about it, why would Honda make EVERYTHING metric except the roof studs? They wouldn’t.

When I first put the standoffs on, I used three on each side. I later removed one (the one at the rear, which is the bottom of the photo). That’s because I discovered that the rail channels on each side are not parallel. They actually slope toward each other and while it may be stylish, it makes it a PITA to install DIY rails, which are arrow-straight. The four studs are plenty strong enough. We still need to deal with the lack of parallelism, but we’ll address that later.

Now you will set a “fender” washer on top of each standoff post. What’s a “fender” washer. It’s just a big-ass washer. The hole in the middle is 1/4″ (or about M6) but it’s wide enough that it won’t slip through the slots in the rail. The big slots give you some adjustment and the fender washer distributes the load across a wider area.

The fender washers, as viewed from the bottom, after the rails are in place.

Step 5 is to use the M6 x 16mm screws along with 1/4″ fender washers and split locks to attach the fore/aft 3-foot rails.

Note the black duct tape that holds the back plastic pieces in place. If this was going to be permanent, I would come up with a more elegant solution. You could put a clip on the rear stud and RTV the plastic in place. However, the tape worked fine for a 6 week stint and was easy to remove when I put the rubber strip back on.

You have some flexibility here. You can reference the rails forward or back, but make sure they are forward enough that you can open the rear hatch! Take a look at the video and the title photo to see how I have them. Leave the screws loose for now because you’ll need to square everything up after you put the solar panel on.

To attach our solar panel assembly with its cross pieces, we’ll use these special strut channel nuts. These are part of the Uni-strut “system” and do not require drilling. The little plastic piece keeps them from falling out, but lets them slide along the rail. The grooves in the metal part fit against the strut hooks and hold the load when you tighten things down.

Note that the Strut Nuts (what I think they should call them) are 1/4″-20 threads, which is why we bought those screws. Be careful not to mix up the M6 and 1/4″-20 screws or you’ll have a tough time telling them apart (oh, I suppose our inch screws are longer, so that’s one way you could tell).

OK, here comes the part where you are “on your own” except for some general instructions. You will want to align the rails on the solar panel assembly so that the side-to-side rails are parallel to the rear of the van. In other words, “square” to the van. Use the same hole on each of the front/rear rails on each side. However, remember when I said that those stud channels are not parallel? Yeah, it turns out that when I positioned this as far back as I wanted, I could not get the slots in the solar panel rails to align with the rails. If I moved the panel forward, I could have found a spot I’m sure, but dammit, I wanted this all the way back. So…..

…I made an auxiliary hole. This photo was taken after the trip, so you can see where the washer was and also that this solar panel rack is plenty strong enough to stay on at speeds up to 90 MPH (tested in South Dakota).

Step 6 is to run the wires into the vehicle. I talk about this in the video but here you can see where I wrap the wires in “convoluted tubing” to protect them. You can buy this on McMaster, but it only comes in large rolls. Instead, go to the electrical department of Lowe’s or Home Depot and buy about 24″ of it. You can find it near the connectors and crimp lugs. It even comes in different colors to match your van! The wires are run through the top channel, out a slot in the bottom and then down into a hole I drilled in the plastic trim piece. This hole can later be sealed with a snap-in hole plug, if you remove the panel.

My current solar panel is only 60 watts, but I designed this to hold two panels of the same size. The trouble is that this panel was no longer available for purchase when I went to buy the second one. I could have bought a Renogy or other brand-aware name, but I refuse to pay more than about $1.10/watt. So I’ll wait for another opportunity to present itself. If need be, I can add a 30W on each side of the 60W. It’s nice to have Options!

Here’s how it looks when you finish. The rails appear to extend over the side of the van, but only at roof level. They are NOT wider than the sides of the van. Trim them if you want, but I like the extra mounting points they provide. You can hang your solar shower bag from them!

If you plan to leave your minivan solar panel on forever, you can stop here. If you want to store it in the offseason, read on.

When it comes time to remove the system, you can just take the four screws out of the lower rail and lift the whole assembly off. Well, maybe…I tried this and put a rag under each of the lower struts, then tipped the whole thing toward the rear. After hopping off the ladder, I lifted it off the back. The thing is, I’m 6′ 4″ and have monkey arms. If you are smaller of stature or have back issues, a better idea is to pull the solar panel assembly off first, then the lower rails. In other words, disassemble in the order you put it together.

You can then put the rubber strips back on (you did save the extra clips, right? The small slice in the rail can be sealed up from the rain and snow with a couple strips of electrical tape. You can’t see it when standing on the ground and you’d have to really look for the tape if you were crawling on the roof.

However, if it really bothers you grab a couple of uncut rails from the junkyard (grab the clips too!) and put your pretty rail in place. I’m not that concerned, so this is what the finished product looks like.

You can store the roof mount solar panel assembly in the garage or shed, but I plan to make a bracket and put it on the roof of my gazeebo to charge a battery for some LED lights. But that’s a project for another day.

The Odyssey Camper is now ready to ferry customers to and from the airport and to business meetings and no one is the wiser.

I decided to build this roof mount before going out on my 2018 summer trip to Colorado and Utah and so, keeping the panel horizontal was fine. However, I’ll continue to use this in the winter months and so, the next step will be to add a tilting mechanism to take advantage of the sun’s low position in the winter sky. Stay Tuned!

–Darren at Odyssey Camper

For a complete list of my DIY minivan camper conversion projects, click on the menu item at the top.