Solar Panels are a key element for off-the-grid vanlife; if you say freedom, we say solar power! The electrical system of our campervan is designed to power our appliances (fan, lights, 12V fridge, etc) and can be charged with solar power, alternator or shore. The present article only covers the installation of the solar panels; if you are wondering “How many watts of solar panels do I need on my van?”, then we have a very comprehensive Electrical System Design Guide for you here:
TIME SPENT ON THE JOB:Ā 6 hours
TOTAL COSTĀ : 570$ USD
MATERIAL:
- 2 xĀ 160W (or 175W) 12 volts panelsĀ (Buy from Amazon)
- 3M VHB double-sided tape 1″ widthĀ Ā (Buy from Amazon)
- 2 x Renogy Z mounting bracketsĀ (Buy from Amazon)
- MC-4 Multibranch Connector pairĀ (Buy from Amazon) (This is to wire the panels in parallel if using a PWM charge controller. If using an MPPT charge controller, do not buy this)
- Right angle cable gland 3/8″Ā (Buy from Amazon)
- 15′ Extension Cable Pair with MC-4 Connectors 8AWG (Buy from Amazon)
- Dicor 551 LSG-1 Lap Sealant (Buy from Amazon)
- Isopropyl alcohol
- Primer, Paint & Clearcoat
TOOLS:
- Drill
- Caulking gun
- File and sandpaper
HOW WE INSTALLED THE SOLAR PANELS ON OUR VAN
1- Test the setup before the installation
Right when weĀ finishedĀ installing everything, we realized that we did not test any of the components! If any item was defectiveĀ (panel, connector, wire), we would have toĀ disassembleĀ everything… Fortunately, things always work for the best so we did not have toĀ undo our work!
To test, we could have just connect the panels to the MC4 parallel connector, then connect to the extension cable, and finally check the voltage at the end of the extension cables. We did that at the very end of our installation.
2- Pre-install brackets on the solar panels (4 brackets for each panel)
It’s easier to do this on the ground…
3- Relocate the brackets in the inside edge
This is to minimize the gap between the panels, so they are installed toward the middle of the roof and are less visible from the ground. A minimum gap shouldĀ be left to account for thermalĀ expansion and for installation access.
4- Install 3M VHB tape on brackets
We selected 3M VHB tape to minimize drilling through the roof. AM Solar have been doing it for a long time and reported to never have lost a panel.Ā Where a screw will grip through the sheet metal, the tape rely solely on the paint to hold; therefore, we don’t recommend to use tape on rusted, damaged or used paint. In other words, we trust the tape method because the van is NEW. Also, we check our panels installation regularly.
Per manufacturer recommendation, the minimum applicationĀ temperature for 4991 tape isĀ 60F.
5- Cut the 30′ extension cable in half and pass it through the glands. Leave about 12 inches between connectors and gland.
It required a lot of force to pass the cableĀ through the gland thanks to the right angle. It’s better to do this onĀ the ground.
6- Pre-fit solar panels on the roof to define location ofĀ cable glands
This extension cable is not very flexible. We found it easier to work with if we install the glands atĀ approximatelyĀ 12 inches from the panels.
Mark the location of the solar panel to avoid having the measure again afterward.
7- Remove solar panels and drill holes for the glands
We pre-drilled and then use a hole saw.
8- Break the sharp edges with a file and smooth the surfaces with a fine sandpaper
To prepare the surface for touch-up.
9- Apply Primer, Paint & Clearcoat on drilled holes
This is an important step to preventĀ corrosion in the future.
TIP: You can have your exact van color prepared for you in almost any auto-parts store. Just give them your color-code (printed on the driverās door frame), year of production and make.
10- Think and prepare cable routing on solar panels
This is to prevent cable chafing on the roof and damaging the paint. We also installed a protective tape on the roof afterward just in case.
Now that we look at the picture below, we’re not sure it will pass the test of time. You might come up with a better idea!
11- Fit solar panels on the roof and connect all the cables
See previous picture.
12- Pass wire through the roof without securing the glands yet
13- Clean roof with isopropyl alcohol, peel offĀ 3M VHB tape and press firmly to adhere
No picture here. We had to act fast and it turned out more complicated than anticipated: you get no access to the center of the roof, the cables must be neatly fittedĀ and you get one chance only to stick the 3M tape at the right place…
14- Fasten the glands to the roof
15- Seal all the brackets and the glands with Dicor Lap Sealant
The bracket are sealed to preventĀ water contamination with the tape; it should help in the long run. We could not seal the inner edge of eachĀ bracketĀ because we had no access.
16- Final Test
We don’t have the charge controller installed yet, but we can ensure there is voltage coming from the panels.
It works!
17- Have a pint of fresh Double I.P.A
We deserved it!
18- Have a Poutine
We know what you are thinking; but we also know that you would love it if you try. This is Quebec fine cuisine.Ā
ON SECOND THOUGHT…
2 years later and we’re still super happy with the solar panels! We did upgrade our PWM solar charge controller for a MPPT solar charge controller, but we updated our Electrical SystemĀ article and Wiring Diagram accordingly. We also reviewed the Victron MPPT charger and the Victron system monitor:
INSPIRATION OF THE MOMENT
Did you ever have this wildĀ dreamĀ of quitting your job and travel the world in a van?Ā These guys had this dream, and went afterĀ it… very motivating reading!
Download the eBook from Amazon.
WANT MORE?
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ABOUT US
Hello! Weāre Isabelle and Antoine š In 2017 we sold our house (and everything in it), quit our engineering careers and moved into our self built campervan. Weāve been on the road since then and every day is an opportunity for a new adventure; weāre chasing our dreams and hopefully it inspires others to do the same!
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CHEERS!
I wanted to introduce myself and thank you for such an amazing informative site. I am building out a 2019 Promaster 2500 and have referenced your site more than any other websites out there for DYI van conversions. In particular your electrical system (I purchased your wiring diagram.) I did deviate from your plan and purchased Renogy 100 watt panels, mppt controller, inverter and DC to DC charger. I haven’t pulled the trigger on a battery yet but I am leaning towards the Renogy 170ah lithium cell. The only con I can find for this battery is the odd size terminal connection. I am about to mount my panels and not sure if I will tape and lap seal like you guys or build a rack. Thank you for your hard work and attention to detail.
Respectfully
Tommy
Hi,
I’ve purchased the electrical diagram/tutorial and I really appreciate your approach, your level of detail, and the website layout in general. I don’t find, however, what you did for the connection between the shore power source and the Samlex battery charger/converter. Specifically, I’m interested in the connections between a 125/250v power plug inlet (typically through the wall of the van) and the charger/converter. Looks like the charger has a std 120v 3-prong plug as the input.
Thanks.
We donāt have any outlet outside the van. We only plug 3-4 time a year, so we wanted to keep it simple. When we plug, we just route an extension cable through a door (or through the b-pillar opening in the rear of the van) and plug it to our shore charger (the samlex). Thatās it!
Cheers!
Antoine,
I just purchased your electrical wiring diagram. Thank you so much for this invaluable resource. I’m a newbie DIY-er and am feeling very overwhelmed. I have two questions about solar panels.
Why did you choose a stiff panel vs. flexible? I like the idea of using the flexible because it’s super lightweight and would have next to no wind resistance on the van roof.
And the NewPowa 175w panel you have linked to Amazon shows an entry gland (?) attached to the back of the panel and your list of items used shows a separate (additional?) entry gland. Do I need to purchase this additional entry gland or is the one tacked to the back of the Newpowa panel all that I need? Thanks for your help.
Hi Mary!
Rigid solar panel are more efficient and are much more durable; a flexible solar panel will deliver less power as it ages. That’s why we went with rigid.
The NewPowa panel doesn’t come with an entry gland; it comes with a MC4 connector. The entry gland is used to make a weatherproof pass-through the roof of the van, while a MC4 connector is used to make the electrical connections (connect the panels in series/parallel or to connect the panels to an extension cable).
Hope that makes sense!
Good luck š
Antoine,
Thanks for your excellent guidance on all aspects of RV conversion. Following your notes I just installed the cable gland and did a test fit of two 200W Newpowa panels using the Newpowa mounting brackets. Due to the curved nature of the roof I think the brackets don’t make enough contact with the roof to permit 100% VHB tape installation (also the tape is hard to remove in the future). I’m therefore considering using screws. To account for the curved roof I’m thinking of adding rubber pads under the brackets and screwing right through them. This would also provide some “shock absorption”. Do you think this is a good idea?
It’s a good idea to prevent metal-to-metal contact (bracket directly on the roof), but don’t use a rubber pad that’s too thick. Something like 1/8″ would work (or maybe use the VHB tape if you purchase it already). Too thick and it’ll add more stress to the screws.
Good luck š
Can you tell me the reason for not using branch connectors with a MPPT controller?
You mean why connecting the panels in series instead of parallel with a MPPT? That’s because a PWM charger cannot convert “over-voltage” (voltage over 12V from the panels) to more AMPS. On the other side, a MPPT charger is able to convert “over-voltage” (voltage over 12V from the panels) into more AMPS.
Note that you CAN use branch connector (parallel) with a MPPT controller; it’s better for partial shading as discuss here: https://faroutride.com/electrical-system/#solar_power
Cheers!
Hello! This may seem like a super basic question but does installing your panels prior to having your battery bank and charge controller pose any sort of safety issue since there will be exposed wires from the panel with no where for the power to go? If so, how did you mitigate this issue? I would love to get my panels installed on my roof soon but I am still a few weeks off from setting up the whole electrical system.
Thanks!
Like you, we installed our panels a few week before connecting them. Just make sure the end of the wires are not exposed (to prevent short circuit).
Good luck!
Hi Guys,
Wondering why you didn’t use the brackets in the middle and just glue/tape the outside edges (of the panels) to the van roof sans brackets. Would be lower average profile and less visible as well. Seems it would work if there is enuf room for the wiring, and might be stronger.
Don
Panels are less efficient at high temperature; leaving a gap is actually a good thing to regulate temperature.
Hi guys! Love all these guides. We just bought our van, and we’re so excited to get started on this project. Solar installation seems like a good place to start. I’m wondering what kind of efficiency you guys see from the Grape Solar panels you have recommended. I’m doing my own due diligence by shopping around and some reviews I’ve seen on other panels around the same rating reported significant efficiency variation, so I was wondering what your experience has been with the panels that you went with. Thanks!
It’s honestly hard to tell how “efficient” they are in the real-world, since there are so many outside factor involved: sun angle, dirt, time of the day, etc, etc. But what I know is that we get up to 27 amp charge input (using an MPPT charger), best case scenario. We have a graph of our input in summer VS winter here: https://faroutride.com/electrical-system
Bottom word: we’re happy with the panels and recommended them!
Hope that helps!
This is a FANTASTIC blog on how tho do a van conversion.
Thanks!! Glad you like it š
I just bought a Promaster…Let the fun begin. Would you install fan first or Solar first?
Thanks,
Eric
Fan! Both ways would work I guess
One point: you may want to install solar first so that you don’t limit the amount of space available on top of your van. We put our fan about 4 feet back from the back of the van, then when we were installing solar, we noticed we could have fit a larger array had we moved the fan back a foot. Live and learn! We just went with slightly smaller panels that did fit in front of our fan.
Would you be able to replace a panel with this setup? It seems like once it’s taped to the roof you might not be able to access the bracket bolts (to the panel) anymore? I don’t want to put a roof rack on the van but am considering taping 2″ angle aluminum to the roof so I can drill through the side of the panel vs the bolt underneath, if it’s not accessible. Thoughts?
You are right, the bracket bolts is not easily accessible anymore! To remove a panel, we might have to remove the 3M tape (it’s removable by heating). You can probably do better than us, the alu angle make sense! (except I recall reading that it could void the panel warranty, but I wouldn’t worry too much about that…).
Cheers!
Hey guys. Did you end up putting bolts through? In previous comments you discussed doing that for extra safety. Hows everything holding up? Just installed three 310w panels on my roof yesterday
No screws.
We check them from time to time and so far it’s holding super strong!
Hi Antoine,
Great post! I had a few questions…
1. What made you decide to use the glands instead of a combiner box? I see most people using a box and I wanted to hear your thoughts.
2. Did you drill a 3/8″ hole for the glands or did they need something a little bigger?
2. Did you use any else besides the Dicor to seal the glands?
Hey,
1. Can’t remember why exactly, I think both solutions are acceptable (unless if you have more than 2 cables a junction box would probably be better)
2. I honestly don’t remember, but looking at the holesaw picture it looks like, maybe, 1/2″?
3. The glands themselves are sealed, but we added Dicor for extra safety (nothing else).
Good luck!
Hey Antoine, So would you use just one Renogy 280 watt or two? Also are you still happy that you installed the MaxAir fan up front? Thanks again
Hi Terry,
I would install one. Of course, it all depends on your needs; if you plan on using induction cooktop and such you might need more…
Because we cook (a lot) in the van in winter, I think the fan up front is a must. If not cooking, front or rear works. The advantage of installing the fan in the rear is that when driving you can just open the front windows and it makes a very good air circulation.
Cheers
I’m looking at adding panels soon. I have a transit as well but I’m concerned that the roof will flex too much with the panels just being mounted to the thin metal roof. How did you anchor things on the inside of the van?
We installed them directly on the roof and it didn’t flex.
We anchored everything inside using Plusnut: faroutride.com/plusnut
Cheers
Ok, just to be clear, the photo in step 15 above shows the angle brackets attaching the solar panel to roof. You just used a standard bolt and nut through the thin metal roof to mount them. I am assuming the plus nuts refer to how you mounted everything else inside the van. Thank for the help š
No bolt and nut! It’s holding with the 3M VHB tape only!
You’re correct about the plusnut; it’s for mounting stuff inside the van.
Hi, Iām enjoying following your van life. Iām doing a similar setup for my own solar system in my ford transit. Could you tell me how you wired your panels, series or parallel and why? Thanks!
We wired them in parallel, to keep the voltage in the 18V area because our PWM Charger Controller works better at this voltage. If you’re going MPPT, I think you can wire them in series, really it depends on your charge controller.
Hope that helps!
Hey Antoine,
What kind of tape did you use to affix the wires underneath the panels? Is it still holding up?
Thanks for all the help
We used red tuck tape, I think it’s still holding, but I would not recommend it… There must be a better way!
About to do this step myself. In your travels, have you come across any better solution? I’m doing my own research and haven’t found any tried and true method yet.
If you have a roof-rack, you could bolt the solar panels on it. Otherwise we would use that method again! Still holding strong 3 years later!
Antoine,
I had an interesting discussion with solar panel retailer.
Not sure if his advice was profit driven or actual good advice, but the theory makes sense:
He said he would advise against using a panel with a footprint larger then the 160w panels you have as the span and surface are of the glass surface on a panel larger then this would be at high risk for cracking due to the body of the van flexing.
Since the cost becomes close to even with one broken panel, I decided it wasn’t s risk I wanted to take…
I could be cursing the decision when I start to install these 6-100w panels instead of 2 300 watt panels lol…
Just thought id let you know!
Wes
I doubt it will crack because
1- People have been using even larger panel for a while (Orton and it’s 300W panel for example)
2- The panel is not entirely glued to the van roof; only 4 points are attached so (if) the roof is to flex, the panel won’t necessary flex too.
Thanks for sharing your thoughts! Future will tell š
Cheers!
Nice work! At one year plus how are the 3M VHB mounts and cable glands enduring the test of time?
It’s all good!
Holding strong!
Very detailed instructions! Thanks for the writeup. I did a very similar install on the roof of my 5th wheel about 1.5 years ago, also using the 3M VHB tape. I did end up losing one of 6 panels while on the highway somewhere in Arkansas… still don’t know where that panel ended up! As a result I installed a single screw in each of the Renogy mounts, and installed a wind-guard in front of the forward set of panels. I’ve since traveled 18,000 miles with all panels still attached. If you are interested in pictures of the wind guard, shoot me an email.
Thanks for the great site and detailed descriptions!
You’re the first to report this. Thanks for letting us know! I think we will add screws, we don’t want to kill anybody…