Mounting solar panels on the roof versus ground

motorbreath · 10-09-2016, 01:59 PM

I am looking into an affordable solar kit and upgraded batteries for next year since we will be boondocking more. I am relatively confident about the battery upgrade and sizing of the solar panels, but am not sure about how I want to mount the panels. Mounting the panels on my TT roof seems to have many drawbacks:

- If my TT is in the shade the panels will not perform well. We prefer to pick spots with shade, which keeps the TT cool.
- The costs and labor involved in mounting the panels to the trailer roof are high and result in additional points of failure for the roof.
- Once mounted to the roof cleaning, tilting, and rotating the panes is difficult and there is additional initial cost for the mounting equipment to support this.

I have found many solar kits which are designed for mounting the panels on the ground. While this does require additional setup and breakdown time, most of the kits allow you to easily fold-up a pair of panels which seems relatively convenient. I do not see many drawbacks to this approach, only benefits:

- installation is simple and requires no modification to the trailer, the system just connects directly to the battery bank. For my TT these are mounted externally, so I do not need to drill any holes!
- the panels can be quite far away from the travel trailer and are mobile, thus we park the TT in the shade but have the panels in the direct sun.
- the panels can be easily cleaned, rotated, tilted, and stowed for the winter.

Am I missing something? Why do roof-mounted panels seem to be the preferred choice? The only thing I can think of is that they are much harder to steal, but we live in Canada and don't worry about such things

bansai · 10-09-2016, 02:21 PM

Portable solar setups are fine if you are ok with the 'setup' required every time you use them, and need to take them down. It is easier to make a permanent install one that you don't even have to think about, it just works, even when you are away from your camper / in storage / etc.. One of the best positives of the portable setups, as you already mentioned - is you can park in the shade and put your panels in the sun. However, I do not consider the panels on the roof to be a big deal when you do it correctly.

I am doing both permanently installed panels on the roof & a smaller portable setup. The one thing you mentioned that isn't correct is " the system just connects directly to the battery bank" Well no - in both cases you will need to install a quality charge controller at a minimum. The more you 'boondock' the more sense a permanent install makes. Going off the grid doesn't have to increase your setup and tear down time for eternity, but by going 'portable' it will.

One thought - you can always start with a portable system.. and if you choose the right panels, you can decide to mount them to the roof later. Nothing to lose with this approach.

Theft isn't as big a deal here as you might think. When you are setup and actively camping, I don't hear stories about people getting their panels ripped off... and IF someone wanted to take them, the ladder is right there anyway. It isn't a factor IMO. The bigger factor is having to mess around with your panels a LOT more + increasing your foot-print wherever you happen to be 'camping' at. I've been at more than one spot where the panels would seriously get in the way if they were on the ground.. the dogs, kids, trip hazards, whatever... the panels are going to be more 'in your face' and less just humming along without anyone even noticing them. I'm looking to reduce the time I spend setting up camp, not increase it. If you don't mind the extra steps required to get your solar system functional, every time - go for it. Sounds like you've already weighed the pros and cons and made up your mind.

motorbreath · 10-09-2016, 02:33 PM

Thanks for the info, the "set it and forget" factor is definitely something I can live without for now since we will be travelling only once a month. I did not mention that the portable systems I am looking at include a charge controller, so I would hook that directly to the battery bank and not the panels.

Quote:

Originally Posted by bansai

I am doing both permanently installed panels on the roof & a smaller portable setup. The one thing you mentioned that isn't correct is " the system just connects directly to the battery bank" Well no - in both cases you will need to install a quality charge controller at a minimum. The more you 'boondock' the more sense a permanent install makes. Going off the grid doesn't have to increase your setup and tear down time for eternity, but by going 'portable' it will.

One thought - you can always start with a portable system.. and if you choose the right panels, you can decide to mount them to the roof later. Nothing to lose with this approach.

**Mustang65** · 10-09-2016, 02:50 PM

As mentioned if you plan on expanding your SOLAR system, you need to research panel voltages and limits of the SOLAR Charge Controllers (Volts and Amps) as they are the crucial part of your system.

We have a RVing with SOLAR social group, you can click on Community above and select Social Groups and "Rving with SOLAR, or click here if you like to take the path of least resistance like me. There is a lot of information there and step by step installs also. Sign up on the page.

There have not been any thefts that I am aware of, but we have had a member or 2 loose one by wind gusts. Just remember, once your start with SOLAR it never ends.....

Oh, my SOLAR is on the roof.. pumps out 20 Amps when the batteries need it.

Don

DanNJanice · 10-09-2016, 05:13 PM

We use two portable solar panels with a piano hinge and two legs to prop them up. Our reasoning was exactly as you stated. We can park in the shade and still have the panels in the sun. We also can adjust the panels throughout the day to maximize available sunlight. We have been doing this for 5 years now and it works great! If I had it to do over again the only thing I might change would be to use flexible solar panels. I think I could mount the flexible panels to a wooden frame and have a far lighter array than I do now.

Seann45 · 10-10-2016, 07:15 AM

IF you put your panels on the ground make sure they are well tied down. Not only can the wind shatter them (happened to me) but they can also develop legs and walk away. The other thing you will have to think about is where will you store the panels when on the road and will they be in the way if you stop for a night somewhere..

DanNJanice · 10-10-2016, 12:49 PM

Quote:

Originally Posted by Seann45

IF you put your panels on the ground make sure they are well tied down. Not only can the wind shatter them (happened to me) but they can also develop legs and walk away. The other thing you will have to think about is where will you store the panels when on the road and will they be in the way if you stop for a night somewhere..

Good point, we had our panels fall off the legs one time. One panel landed on a rock and broke.
Another down side that the OP should be aware of is a portable array is fairly limited in size. It is just not feasible IMO to setup 500-600 watts of panels in a portable array. In my case I can get by on 200 watts virtually all the time, so not an issue for me.

Cdash · 10-10-2016, 01:10 PM

Renogy sells a 200 watt add starter kit that comes with 2 - 100 watt panels, a cheap controller, wires, fittings and roof brackets for $400ish.

I installed the controller in the compartment behind the batteries and wired my "solar on the side" into the charge controller. I used the panels as portables, plugging into the solar on the side plug. To make the panels easier to manage, I connected the two with hinges. I keep them in the box that they were shipped in with the foam sheet that separated them during shipping. (I've posted details previously)

I too like shady spots and this setup helps me reach sun. I'm only using 25' cables, but may pick up another 25' for an extension. I still need to make a stand for them, will probably make something out of pvc. For the once or twice a year that we are of grid, this works well for us.

I may consider roof mount in the future, but that would be to keep batteries (2 - T105's) charged while on the road. Considering adding an inverter to run my outdoor half fridge, but need to figure out power consumption to determine if it will be worth it.

bdreinv · 10-10-2016, 03:26 PM

We had same concerns anyways installed a 275 watt 60 cell industrial panel from AZ Wind and Sun Flagstaff.$250.00 and a 30 amp Blue Sky Controller MPPT 260.00 from ebay.The 275 watt panel is whats known as an industrial panel about 85 cents per watt.My only regret is not going with 40 amp controller, my system now maxes out at 290 amp.Other than that works great was simple to install my 2016 Eagle was pre wired for panel and controller.

motorbreath · 10-10-2016, 05:29 PM

We are looking at a 200W system, something entry-level that comes with an external charge controller so we can connect directly to the battery. More good information, I'll make sure to buy stakes along with the solar kit. This will add time to the setup, but when we are not moving alot so I am not too concerned (yet!).

Quote:

Originally Posted by DanNJanice

Good point, we had our panels fall off the legs one time. One panel landed on a rock and broke.
Another down side that the OP should be aware of is a portable array is fairly limited in size. It is just not feasible IMO to setup 500-600 watts of panels in a portable array. In my case I can get by on 200 watts virtually all the time, so not an issue for me.

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