gift
Collection of 14 Permaculture/Homesteading Cheat-Sheets, Worksheets, and Guides
will be released to subscribers in: soon!
  • Post Reply Bookmark Topic Watch Topic
  • New Topic
permaculture forums growies critters building homesteading energy monies kitchen purity ungarbage community wilderness fiber arts art permaculture artisans regional education skip experiences global resources cider press projects digital market permies.com pie forums private forums all forums
this forum made possible by our volunteer staff, including ...
master stewards:
  • Anne Miller
  • Leigh Tate
  • Pearl Sutton
  • r ranson
stewards:
  • Nicole Alderman
  • paul wheaton
  • Mike Haasl
master gardeners:
  • Carla Burke
  • John F Dean
  • Jay Angler
  • Beau Davidson
gardeners:
  • Jordan Holland
  • thomas rubino
  • Nancy Reading

RV solar

 
Posts: 30
Location: Pennswoods
1
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
Does anyone have experience paying an electrician to install solar in an off grid rv? It will be a ground mount system.

I’ve been buying all the components needed since last summer, and the frustrating thing is that the more I research how to safely install it the more stuff I find that I was missing, and it’s concerning that “I won’t know what I don’t know” and I’ll end up with it being unsafe. Electrical always sketches me out. It’s extremely frustrating that all the tutorials/pages give conflicting/vague info, I’m just ready to be done with it and pay someone to do it.

So if anyone has done this, what did it cost and how hard is it to find someone who knows how to properly set up solar?
 
pollinator
Posts: 698
153
3
tiny house food preservation cooking rocket stoves homestead
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
This site has tons of good info.

https://www.mobile-solarpower.com

Will the guy who wrote this wiki has a youtube channel and has lived on the road for years in an RV.

Mart
 
pollinator
Posts: 219
Location: Clackamas County, OR (zone 7)
125
  • Likes 1
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
Hey, I have been off-grid for years, and when I started out I had zero experience with anything other than a few electronics projects. It can be overwhelming at first, especially if you did not pay attention in Physics class - and you thought you would never need any of that knowledge in real life, HA!

Anyway, joking aside, a simple solar system can be done by a complete amateur, and be as completely safe as you will get in the real world (which is full of perils that we mostly just ignore). Every time you plug something into an ordinary wall outlet, your fingers are about an inch from a potentially deadly run in with 120 volts.

So if you are game to learn something new, I, and other experienced users on this site can walk you through what you need to do.

Voltages under 48v are generally considered safe. On a 24v system, you could dig around in the main fuse box with bare hands and not be in any danger. If you wire your panels at a reasonable voltage, the most dangerous thing in your system from an electrocution standpoint is going to be the outlet on the inverter. Electrical fires are rare, and they can be easily avoided. You will need to use correctly sized wiring to handle the loads you are planning on running. You will need to fuse or use breakers on every wire coming from the battery. You will need to make sure your electrical connections are tight, and enclosed properly. Thats really about it.

Anyway, I would be glad to help if you feel like you have a bunch of questions and are having a hard time finding answers.
 
Posts: 8
4
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
It can be very difficult to find someone that is good with off grid solar.  Almost everyone you find online is going to be a grid-tied solar installer, which is a completely different beast.

I have a company called JRL Solar in the DFW area that does off grid solar only.  I have done several RV's and numerous off grid solar installations.  I am getting ready to do a big one for a guy for his well pump on his rural retreat.  I don't travel very far but if you want some help or advice, I'm happy to help.
 
Ivanson Lance
Posts: 30
Location: Pennswoods
1
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
I would like to learn how to do it but it’s frustrating going to “reputable sources” only to find them conflicting or omitting important information. We got what we thought was a complete kit minus battery a year ago, every time I went to research how to connect it I find more things missing. Yesterday for the eighth time I realized I had to add in safety features with a GFDI.

Contacted go power because in there online manual and NEC said it needs an external  GFDI device. They said they don’t know what that is and told me “we’ve done thousands without them” 🙄. At this point I just want to throw it away and use candles!
 
Ivanson Lance
Posts: 30
Location: Pennswoods
1
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator

Carl Nystrom wrote:Hey, I have been off-grid for years, and when I started out I had zero experience with anything other than a few electronics projects. It can be overwhelming at first, especially if you did not pay attention in Physics class - and you thought you would never need any of that knowledge in real life, HA!

Anyway, joking aside, a simple solar system can be done by a complete amateur, and be as completely safe as you will get in the real world (which is full of perils that we mostly just ignore). Every time you plug something into an ordinary wall outlet, your fingers are about an inch from a potentially deadly run in with 120 volts.

So if you are game to learn something new, I, and other experienced users on this site can walk you through what you need to do.

Voltages under 48v are generally considered safe. On a 24v system, you could dig around in the main fuse box with bare hands and not be in any danger. If you wire your panels at a reasonable voltage, the most dangerous thing in your system from an electrocution standpoint is going to be the outlet on the inverter. Electrical fires are rare, and they can be easily avoided. You will need to use correctly sized wiring to handle the loads you are planning on running. You will need to fuse or use breakers on every wire coming from the battery. You will need to make sure your electrical connections are tight, and enclosed properly. Thats really about it.

Anyway, I would be glad to help if you feel like you have a bunch of questions and are having a hard time finding answers.



Forgot to tag you above. But my biggest concern is fire, we sized all the wires according to what was recommended on charts, and fused the same way between each component. Grounding all metal bodies of components and one terminal of the battery
 
Carl Nystrom
pollinator
Posts: 219
Location: Clackamas County, OR (zone 7)
125
  • Likes 2
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
It sounds like you are on the right track. Tell me a little about the system: How many panels, what voltage do they output (Voc), how are they going to be wired in series/parallel?

Ground fault interrupting circuits I believe are called for by the NEC on any roof-mounted solar system, but I think they are overkill for just a handful of panels that are wired at low voltage. They are not designed to detect very small ground faults like in the GFCI in a household system, so they are not primarily trying to protect people from transmitting ground fault current. The ones I have used have a ganged half-amp breaker that serves as the sole connecting point for your battery minus terminal to ground, along with a larger breaker that shuts off power coming from the panels. This means that if the grounding system becomes energized by the panels, enough power will flow through the half-amp breaker to quickly trip it, and shut off the larger breaker. This will not correct the fault, but it will alert you to it.

Solar panels are current limited, so if the wires are properly sized, the panels will never be able to burn them up. I have GFDI breakers on my house system (60v), but when I put up some panels for my shop at 24v, I decided to just skip it. It is a simple system, and the likelihood of a fault even developing seems very low. If you are paranoid, you can include it, it is not that much extra work, but even without I would bet your system would be many times safer than using candles!


 
Ivanson Lance
Posts: 30
Location: Pennswoods
1
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator

Carl Nystrom wrote:It sounds like you are on the right track. Tell me a little about the system: How many panels, what voltage do they output (Voc), how are they going to be wired in series/parallel?

Ground fault interrupting circuits I believe are called for by the NEC on any roof-mounted solar system, but I think they are overkill for just a handful of panels that are wired at low voltage. They are not designed to detect very small ground faults like in the GFCI in a household system, so they are not primarily trying to protect people from transmitting ground fault current. The ones I have used have a ganged half-amp breaker that serves as the sole connecting point for your battery minus terminal to ground, along with a larger breaker that shuts off power coming from the panels. This means that if the grounding system becomes energized by the panels, enough power will flow through the half-amp breaker to quickly trip it, and shut off the larger breaker. This will not correct the fault, but it will alert you to it.

Solar panels are current limited, so if the wires are properly sized, the panels will never be able to burn them up. I have GFDI breakers on my house system (60v), but when I put up some panels for my shop at 24v, I decided to just skip it. It is a simple system, and the likelihood of a fault even developing seems very low. If you are paranoid, you can include it, it is not that much extra work, but even without I would bet your system would be many times safer than using candles!





I have I believe 2x 215 panels, planning on doing 12 volt series setup with it. From what I can see most people are saying it’s only relevant in large commercial setup to use the GFDI but it’s annoying that both the manual and the regulations say it’s required if no ones using it. For paranoia sake what kind of gfdi would I be looking for?

Candles and woodstoves are easy, just need to insulate/shield/distance and you’re golden. This stuff has me scribbling on the walls like a madman haha

 
Carl Nystrom
pollinator
Posts: 219
Location: Clackamas County, OR (zone 7)
125
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
The one I am using is this:

https://www.solar-electric.com/mndc-gfp.html?msclkid=daa39adf7c6b12017387fa0a3dbb9a8a&utm_source=bing&utm_medium=cpc&utm_campaign=Shopping%20-%20All%20Products&utm_term=4588536901185459&utm_content=All%20Products

On a 12v system, 63 amps is 753 watts, so your 2x 215w panels will work fine. Since you are using 215W panels, I suspect that they are designed to be used with a 12v system - generally this will mean they have an open circuit voltage of something like 18v. That info will all be on the nameplate on the back of the panel somewhere. If you are going to use a 12v battery bank, then run the two panels in parallel, and you will be golden. If you want to use a 24v system, you could run them in series, and your panels would still only max out at 36v, which is not hazardous.


Here is the install guide on that ground fault protectors, btw:

https://www.solar-electric.com/lib/wind-sun/GFP-install.pdf

The diagram looks complicated, but some of the stuff is not really relevant to you. You can ignore the PV combiner box and lightning arrestor for example. You can just connect your panels together with an MC4 splitter and then wire them from there to the breaker/ controller. So basically, the positive wire from the panels will go through a disconnect breaker, then the GFDI, then to the controller. From there it goes to the controllers breaker, and the batteries. Negative would go to the controller, then the batteries, and the only place you ground the negative is through the small side of the GFDI from the battery. I dont know what all your kit came with, but I found you can buy pieces of DIN rail, and then mount all the breakers in a small load center from the hardware store. You could also just screw the din rail to the wall, because seriously, its super low voltage.
 
Ivanson Lance
Posts: 30
Location: Pennswoods
1
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
Thanks for your help, I think we’re going to do without the gfdi as everyone I’m talking to says it’s unnecessary for something of this size.

I’m making a diagram now with all the sizes of everything before I start assembling it. Looking back on the display setup from the store I bought this at I noticed it was strange how they have the charge controller connecting to the battery by using the lug on the 300 amp fuse. I guess this is just a way of using less wire to make the connection and is not providing any protection to the battery? Is it safe to set it up this way?

168252B4-4292-46BA-A25D-0DEA6211D603.png
[Thumbnail for 168252B4-4292-46BA-A25D-0DEA6211D603.png]
 
Carl Nystrom
pollinator
Posts: 219
Location: Clackamas County, OR (zone 7)
125
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator

I guess this is just a way of using less wire to make the connection and is not providing any protection to the battery?  



Using one lug of a component to connect multiple connectors is done all the time, but in this case it is very sloppy. The fuses are there to provide protection for the wires. EVERY wire that connects to your battery must be fused to protect it FROM the battery. If your charge controller fails (and if I recall correctly, they tend to fail as a short circuit) then the battery will try and push more than 300Amps through it. A single lead acid battery can push 500+ amps at below freezing temperatures.

In this configuration you would need to size the wires to and from the controller to handle 300A, so probably at least 2/0 copper (dont forget that the return path will also carry the same current). It looks like the wire on there is fairly beefy, and seeing as it is in open air, and pretty short, I would guess that the fuse would blow before it caught your plywood on fire. But that is just a guess from a stranger on the internet, so its worth what you pay for it. Still, much better would be to have Battery -> 300A fuse with 2/0 -> Busbar (capable of handling 300 Amps - this is why you dont do 12 volts, kids) -> then from there you put another fuse that is sized for the smallest wire that will carry at least the full rated output of your controller. What is that on there, like 4awg maybe? If so, it should be able to carry like 95Amps if it has 90 degree C rated insulation.
 
Ivanson Lance
Posts: 30
Location: Pennswoods
1
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator

Carl Nystrom wrote:

I guess this is just a way of using less wire to make the connection and is not providing any protection to the battery?  



Using one lug of a component to connect multiple connectors is done all the time, but in this case it is very sloppy. The fuses are there to provide protection for the wires. EVERY wire that connects to your battery must be fused to protect it FROM the battery. If your charge controller fails (and if I recall correctly, they tend to fail as a short circuit) then the battery will try and push more than 300Amps through it. A single lead acid battery can push 500+ amps at below freezing temperatures.

In this configuration you would need to size the wires to and from the controller to handle 300A, so probably at least 2/0 copper (dont forget that the return path will also carry the same current). It looks like the wire on there is fairly beefy, and seeing as it is in open air, and pretty short, I would guess that the fuse would blow before it caught your plywood on fire. But that is just a guess from a stranger on the internet, so its worth what you pay for it. Still, much better would be to have Battery -> 300A fuse with 2/0 -> Busbar (capable of handling 300 Amps - this is why you dont do 12 volts, kids) -> then from there you put another fuse that is sized for the smallest wire that will carry at least the full rated output of your controller. What is that on there, like 4awg maybe? If so, it should be able to carry like 95Amps if it has 90 degree C rated insulation.




Would it then make more sense for the charge controller wire to go to the same lug as the inverter that way they’re both protected from the battery?

How would a busbar help this situation?

Also i was not tracking that the wire from the charge controller had to be that large, I saw elsewhere that for a 30amp charge controller like I have you could go as low as 12 awg and I was planning on using 6awg. Foiled again!
FFBC33AE-B048-4976-827A-D0F58B783CBC.png
[Thumbnail for FFBC33AE-B048-4976-827A-D0F58B783CBC.png]
 
Carl Nystrom
pollinator
Posts: 219
Location: Clackamas County, OR (zone 7)
125
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
Sorry, I had an antsy toddler climbing on me when I was trying to write my last post, and now that I look at it again, I see that I was looking at the circuit backwards. In your picture, the charge controller is connected without ANY fuse between it and the battery. If the charge controller were to have a catastrophic failure (and they do happen) the batteries would push so much current through that wire that it would turn red-hot and catch on fire. Fuses. Must. Be. On. Every. Wire.

Here is a demonstration of what happens when you short circuit a battery:


I am not really sure why a system of this size would have a 300Amp fuse in it to start with, but if you intend to use it, I would make something that looks like this:



The main fuse protects your main battery leads: if you drop a wrench between the two bus bars, it will open if 300 amps flow, and since all the parts are rated for 300 amps, you will be replacing the fuse, not everything that burns down in the resulting fire.

If the charge controller gets fried: the 30 amp fuse will blow before the 12ga wire is melted, since 12ga can only sustain about 30 amps

If the inverter shorts out, same thing, the fuse protects the wiring.

If it were me, and I was not thinking of major upgrades down the road, I would probably scrap the 300A fuse and put in a 100A fuse directly to the inverter.


Busbars are nice to have if you want to add more circuits later, and you might find that you want to add a battery charger to use a generator, or some 12volt circuits to run a few lights without the inverter or whatever.

Edit: Also, oversizing the wire relative to the fuse is fine electrically: if you want to run 6 ga wires on a 30A fuse, go for it. It reduces voltage drop, but on short runs like this there is really not much point. The wire costs a lot more, so generally, just stick to whatever the chart you are using tells you. I personally would run 10 ga wire for 30 Amps, but 12 would i am sure be okay in this application.
 
pollinator
Posts: 205
Location: Southern Utah
46
chicken building homestead
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
I had zero experience with solar when I installed the solar panels on my trailer.  After a couple weeks of research online of available kits I ordered the one I liked and using their easy to follow instructions I installed it myself.  It was not difficult at all, aside from the fabrication of the frame on the roof of the trailer which I figured out myself.  I mounted the solar panels to the roof, flat, using 2" square aluminum tubing so the panels sat flat  and they have handled 90mph speeds on the freeway without any problem.  The plus side to this is the solar panels shade that portion of the roof and it is considerably cooler on that portion of the ceiling compared to the rest of the trailer.
If you have any DIY abilities I believe you can install a solar system yourself.  Usually the manufacturer has videos on how to do the connections.  You can pay someone to do this for you but you could save a munch of cash doing it yourself.  Even if mounting the panels on a pole in the yard it wont be very difficult.  The hardest part will be digging the hole for the mounting post.
 
Ivanson Lance
Posts: 30
Location: Pennswoods
1
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator

Michael Fundaro wrote:I had zero experience with solar when I installed the solar panels on my trailer.  After a couple weeks of research online of available kits I ordered the one I liked and using their easy to follow instructions I installed it myself.  It was not difficult at all, aside from the fabrication of the frame on the roof of the trailer which I figured out myself.  I mounted the solar panels to the roof, flat, using 2" square aluminum tubing so the panels sat flat  and they have handled 90mph speeds on the freeway without any problem.  The plus side to this is the solar panels shade that portion of the roof and it is considerably cooler on that portion of the ceiling compared to the rest of the trailer.
If you have any DIY abilities I believe you can install a solar system yourself.  Usually the manufacturer has videos on how to do the connections.  You can pay someone to do this for you but you could save a munch of cash doing it yourself.  Even if mounting the panels on a pole in the yard it wont be very difficult.  The hardest part will be digging the hole for the mounting post.




I’m handy when it comes to building stuff, worked as a timber framer etc but I have zero electrical experience. I wish I would have bought a complete kit, but I wasn’t really sure what size I would need, which is why I went to a store so they could help me size it. But the guy at the store didn’t really understand all the safeties you need in place as can be seen above.

Our property is mostly in the woods, so we’re going to run the panels 50 feet to a clearing. We also have a sloped tin roof on our trailer since rv roofs are garbage, does a good job to buffer against the outside temperature
 
Ivanson Lance
Posts: 30
Location: Pennswoods
1
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator

Carl Nystrom wrote:Sorry, I had an antsy toddler climbing on me when I was trying to write my last post, and now that I look at it again, I see that I was looking at the circuit backwards. In your picture, the charge controller is connected without ANY fuse between it and the battery. If the charge controller were to have a catastrophic failure (and they do happen) the batteries would push so much current through that wire that it would turn red-hot and catch on fire. Fuses. Must. Be. On. Every. Wire.

Here is a demonstration of what happens when you short circuit a battery:
https://www.youtube.com/watch?v=xESCXFz8ZQE

I am not really sure why a system of this size would have a 300Amp fuse in it to start with, but if you intend to use it, I would make something that looks like this:



The main fuse protects your main battery leads: if you drop a wrench between the two bus bars, it will open if 300 amps flow, and since all the parts are rated for 300 amps, you will be replacing the fuse, not everything that burns down in the resulting fire.

If the charge controller gets fried: the 30 amp fuse will blow before the 12ga wire is melted, since 12ga can only sustain about 30 amps

If the inverter shorts out, same thing, the fuse protects the wiring.

If it were me, and I was not thinking of major upgrades down the road, I would probably scrap the 300A fuse and put in a 100A fuse directly to the inverter.


Busbars are nice to have if you want to add more circuits later, and you might find that you want to add a battery charger to use a generator, or some 12volt circuits to run a few lights without the inverter or whatever.

Edit: Also, oversizing the wire relative to the fuse is fine electrically: if you want to run 6 ga wires on a 30A fuse, go for it. It reduces voltage drop, but on short runs like this there is really not much point. The wire costs a lot more, so generally, just stick to whatever the chart you are using tells you. I personally would run 10 ga wire for 30 Amps, but 12 would i am sure be okay in this application.




Yeah the guy that set these up seems to be missing basically all safety features.

I like what you’re saying about the busbar for running some 12v stuff off of, that’s definitely something I’m interested in but figured I’d cross that bridge when I get there. I’m going to add in the bus bars like you showed but here’s my diagram so far. Also it sounds like you’re saying anything bigger than 12g will work, I have a bunch of #10 and #6 my dad gave me so I’ll probably do #10 between the charge controller and battery. Let me know what you think or if I’m missing anything else.
41E39588-BAC3-4FEC-86FF-97A710009830.jpeg
[Thumbnail for 41E39588-BAC3-4FEC-86FF-97A710009830.jpeg]
 
Posts: 29
3
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator

Installing an off grid solar panel system also requires you to set up all the necessary junction boxes and controllers inside your home, which can be quite tedious. You can choose to hire a professional to help you out with that if you’re not entirely comfortable doing it yourself. If you need extra help setting up your solar panel van kit, you can try your luck with the brand’s technical assistance hotline if it’s available. You can also check out YouTube videos or public forums like Reddit to see if other solar panel users have uploaded instructions and other helpful tips.
 
Posts: 4
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
Hopefully the answers to your solution might be in the information shared below will help:

1. Calculate your load
2. Solar panel selection
3. Battery selection
4. Charge controller selection
5. Inverter Selection
6. Series and Parallel connections
7. Wiring
8. Selecting the solar cable
9. Selecting the correct size power inverter battery cables
10. Mounting the solar panels
11. Inverter and Battery stand
12. Solar PV design worksheet
 
Robert Hogward
Posts: 29
3
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
The main point of using solar panels in your van is to get the energy you need to sustain yourself on the road. Ensure that the solar panels have a high enough voltage or amperage to power up your appliances and charge your devices. A slew of 100-200W panels should be enough for a decent-sized camper van with essential appliances and lighting. If you have a bigger vehicle with additional entertainment gadgets, you might think about bumping it up to a 300W solar panel for campervan.
 
Posts: 1
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
If you're considering installing solar panels on your RV, you may be wondering about the cost. Solar panels are a great way to reduce your reliance on fossil fuels, but they can be expensive to install. Fortunately, there are a number of ways to save money on installation costs.
One way to save money is to install the Florida home solar power systems yourself with help of. This can be a great option if you're handy and have some experience with electrical work. However, it's important to make sure that you follow all safety precautions when working with electricity. If you're not comfortable doing the work yourself, it's best to hire a professional.
 
A timing clock, fuse wire, high explosives and a tiny ad:
3D Plans - Pebble Style Rocket Mass Heater
https://permies.com/wiki/193712/Plans-Pebble-Style-Rocket-Mass
reply
    Bookmark Topic Watch Topic
  • New Topic