Solar panel location

[Steve F]

So I got given a 167W 24V panel today and it's big. My question is how critical is the location, obviously there are some ideals but with the size of it and my requirements it may be a non issue.

Here's my setup, 100AH sealed battery, all LED lighting, car stereo and fold down DVD player (lucky to use 1hr a day) and the occasional charging of laptops and phones etc. The fridge stays in the Jeep most of the time hooked to it's second battery but may occasionally come out and hook up to the camper if I dont drive anywhere for a few days and the second battery starts to run down.

I was planning on mounting the 167W panel on the roof behind the RTT and pretty much have it setup there permanently. I also have a 30W panel that I place in the best spot as the sun moves around, so all up I'll have 200W on separate regulators, the one for the big panel takes a 24V input and gives an output suitable for 12V batteries its also a MPPT regulator.

Anyway, here's a pic of my free panel and the size. A quick test at 3:00pm on a winters afternoon with dappled sun and it was putting out just over 3A

Cheers
Steve

 

[YukonRob]

Is the panel longer than the trailer is wide?
Could you mount it on a slide under the RTT and then slide it out when you park?

 

[JIMBO]

:sombrero: One thing about SOLAR PANELS, is you hafta keep them in direct sunlight, as dirct as possible-


I can get my full 60W/12v (3amp) output, most of the day

You just have to be careful of any games/traffic !

If you have it mounted permanently--too hard to follow the sun-unless you're in the desert !

:costumed-smiley-007:wings: JIMBO

 

[adventureduo]

Im with Jimbo on this one, if you dont have to mount it full time i wouldn't. Reaon being, you'll lose significant power throughout the day having it facing straight up and actually you'll have only one high point mid day usually. Even a tree limb can knock your power output down considerably. We chose an easel setup for our panel so that it can be pointed whichever the sunlight is stongest. When in transport you can carry it in your RTT as a huge safe, soft carrying bag. Also, on trips where we won't be needing it, we leave it behind as to shed a few lbs of un-needed gear.

 

[Steve F]

Is the panel longer than the trailer is wide?
Could you mount it on a slide under the RTT and then slide it out when you park?

Its about 1/2" less than the width of the trailer so I can mount it on the roof for transport at least. Trouble is its a bit big/heavy to move it around all the time if I don't need to. It's too long to fit in the RTT.

Looks like I might have to try and make a fold out frame so I can prop it up next to the TD, the only other thing that bothers me is security, at least on the roof it's safe.

Cheers
Steve

 

[dwh]

I could see putting in on the top of the front slope. Of course, then you'd have to park with the nose of the trailer facing the sun, but at least the tent wouldn't shade it.

And if there is a window on the front, put it on a hinge so it can serve double duty as an awning.

 

[Steve F]

Yep, there's a window on the front. I think I might put it behind the tent and then have it slide out the back above the rear hatch or just angle up and face the rear of the camper to the North (sun in the Northern sky down here )

Cheers
Steve

 

[Herbie]

I'm in a similar boat and looking for opinions. I just scored a pair of BP 150 watt residential panels. They're friggen HUGE (3'x5'), but even using just one panel would almost be more power than I can currently use, if operating at peak efficiency.

In my case, the top of my pop-top van is about 4' 6" wide, so mounting across the van is out. I could mount it lengthwise and then try to park facing north, in which case popping the top would give me a good southern tilt, but parking isn't always negotiable where I camp. I suppose I could work out a mounting scheme that lets me tilt to either side, but I'm curious what my sun exposure would be with the top popped up... probably not worth the effort. If I park facing south, it's zero solar anyway....

I know being able to move it would be best, but these things are heavy enough (30+ lbs) that due to their size they're awkward to move, not to mention storage is a HUGE problem, since they don't fit width-wise inside the van. So either I rigid mount it to the roof, or "store" it on the roof then haul the massive thing down and move it around.

Since I got the panels for free, my initial instinct was to be excited that I could justify springing for the MPPT controller, but now that I'm looking at the logistics of mounting one of these beasts, I think I might be better off buying a smaller panel and then settling for a PWM controller for now...

 

[dwh]

I just scored a pair of BP 150 watt residential panels. ... Since I got the panels for free, my initial instinct was to be excited that I could justify springing for the MPPT controller, but now that I'm looking at the logistics of mounting one of these beasts, I think I might be better off buying a smaller panel and then settling for a PWM controller for now...

You probably already know this, but depending on the output voltage of the panel, you might be required to use MPPT to step it down for battery charging.

Hrmmm...3x5...one of those would fit on the roof of my camper if I relocated the 14" roof vent further back a bit...

Except that I too wouldn't want to spend the bucks for MPPT. Kind of got my eye on the SunSaver Duo with remote meter...

 

[dwh]

(sun in the Northern sky down here )

Cheers
Steve

Ha! You caught me! When I originally posted that, I DID say "face the front of the trailer to the south". Then I realized my mistake and quickly edited to fix it - hoping I wouldn't get caught!

Busted...

 

[Herbie]

You probably already know this, but depending on the output voltage of the panel, you might be required to use MPPT to step it down for battery charging.

Yes, they're 24v panels with a Vmp of like 35v, so if I use them, it's gotta be MPPT. Given the "cost" of the panels, the price of a Sunsaver MPPT was easy to swallow, but if I end up actually having to pay for panels, I might have to "settle" for a PWM based system.

 

[dwh]

Yes, they're 24v panels with a Vmp of like 35v, so if I use them, it's gotta be MPPT. Given the "cost" of the panels, the price of a Sunsaver MPPT was easy to swallow, but if I end up actually having to pay for panels, I might have to "settle" for a PWM based system.

I like PWM. I just can't see paying for MPPT for a small system, unless the panel voltage requires it.

My van already has a split-charge relay, so that's one main/aux dual battery charging system there.

I'm planning to change out the shore power battery charger (antique Shumacher) for a Samlex SEC-1215a, which can do up to 3 batteries/banks. It has to be set in 2-stage mode to do that (fine with me), and shares the current between batteries via internal diode isolation, but that's a second main/aux dual battery charging system.

If and when I add solar, then the SunSaver Duo will also do dual batteries, so that's a perfect unit to finish off the charging system. And it accepts the standard Morningstar RM-1 remote meter. Sweet. Just need the remote temp sensor to be complete and proper.


Sorry OP, end of hijack.

 

[Steve F]

I ended up using some H profile aluminium with angle bracket on top to make a raised platform that guides the panel off and on. I'll add some carpet on it so I can slide the panel on and bolt it down in each corner. Then when I reach my destination I'll either leave it on the roof or unbolt it and slide it off and put it in the optimum spot.

My regulator (MPPT from ebay with good results from other) reports how many amps have gone into the battery so I'll see what I get in a day with it on the roof and if it isn't enough then I'll take it off and place in the better spot.

The pic also shows my portable 30W panel that I have on the roof at the moment just to keep the battery topped up before I go away at Easter.

Cheers
Steve

 

[dwh]

I think you need to send it back and get one that's an inch wider.

Perfect fit. Nice.

 

[TCcruzn]

Check out the BZ mppt controller They are very reasonably priced ( around $100). The extra juice you get from a MPPT is well worth the extra dough. I use one with a AM solar panel.