Solar panels, fixed to the roof, adjustable on the roof, or portable?

Fatboyz

Observer
Planning for my solar install this summer. Wondering about whether I should mount them solid to the roof flat. Rig up a hinge so I can angle them when in use and flat for travel, or also have them so I can remove them and have them off to the side of the rig. I'm thinking removable might be a good option if the rig is parked under a shade tree and I can remote them into the sun?
 

Wilbah

Adventurer
I've thought about this too and thought having them somewhat tucked into a roof rack made sense (for protection) with a "hinge" on each side plus a "bar" to adjust the angle for either side so that no matter what side is toward the sun I could get it and also adjust the angle to maximize the sunlight. On paper I have the panels attached to a frame that has a round tube on either end with a pin that holds it in place. For travel "both" pins (I might do 2 "tubes" on each side rather than one long one, in which case it would be 4 pins) are in place and locked holding the panel. When I get to a site pull the pin (or pins) on the side I want to tip toward the sun. And it would have an extension under it that lifts up/down and locks in place to hold the angle I want. Not as good as a rotating one but easy to deploy and out of the way for travel. I'm in NE so between woods and terrain having the ability to tilt might make a big difference in what I would get for charging. I think in the Southwest you might be fine just mounting it flat on the roof of a vehicle I dunno. I'm sure others here with more experience than me can add their knowledge.

Of course like a lot of my "plans" its all in my head so I cant show you anything definitive right now sorry! smh. ha!
 

rruff

Explorer
My advice would be to keep it simple.

If you don't have free roof space, then I'd just use portable with a long cord. I'd have the portable panel regardless for shade in summer. Get one that is light and folds up. If you do have free roof space, then I'd mount a panel permanently on the roof, just so I'd rarely have to set up the portable. A hinge and tilting would be helpful if you are in the far north in winter. Else I wouldn't bother with tilt, just make the panel bigger if you can.
 

Joe917

Explorer
Anything complicated is a PITA. Mount it flat and make sure nothing on the roof shades it. I would only go portable for small vehicles. What is your rig?
 

pdxfrogdog

Adventurer
I'm a solar suitcase fan. As OP indicated, being able to park your rig in the shade but still get the panels out into optimal sunlight is a nice option. Keeps power consumption down if your fridge is in a shaded vehicle vs full sun. Many suitcases fix the solar controller to the back of the panels... I would suggest changing that so the controller is on the battery side of the wire. This way you can have a much longer run of wire to the panels and the controller is close to the battery in the shade where the temp compensation is accurate. I use 50 to 60ft of 12ga low voltage landscape wire (home depot) to connect the panels to the charge controller which is 12" from my house battery.
 

Joe917

Explorer
I had a sliding panel under my roof rack and eventually switched to a 100W Renology Suitcase (portable) with a 40ft cable. Here in BC, fixed-mounted panels are useless. Even in the best, sunniest summer days, with the portable panel positioned directly into mid-day sun, it gets around 85-90W of input. I firmly believe that in our climate, anything other than a correctly positioned portable panel will be utterly useless. I suspect Alberta to be quite similar.

Fixed flat panels work very well, even in Alaska we got enough to get recharged as long as it was not overcast. Any kind or sliding rack set up is hard to avoid shading. Shading kills output. You have a small rig so a portable panel makes sense, for larger trucks flat is best.
 

rayra

Expedition Leader
"Solar panels, fixed to the roof, adjustable on the roof, or portable?"


I'm fixing to do all three. Starting with a folding panel kit, already had a solid roof deck for other reasons, working on the custom framework design and fabrication right now.

My fiddlin' with solar starts around here -
http://forum.expeditionportal.com/t...erks-topic-02-k1500-Z71?p=2356698#post2356698

solarpanelmount07.jpg
solarpanelmount01.jpg
solarpanelmount17.jpg
 
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rayra

Expedition Leader
Anything complicated is a PITA. Mount it flat and make sure nothing on the roof shades it. I would only go portable for small vehicles. What is your rig?

What the hell is "complicated" about putting legs on a roof panel so set an optimum sun-facing angle? Leaving panels flat in high latitudes or winter season and you might as well not have them at all.

And 'portable' is highly desirable when you want to shade your vehicle and camp, but want your panels in full sun.
 

Fatboyz

Observer
Joe917, my unit is anFord 550 long wheel base crew cab with a 11' uhaul with a 3' overhang over the cab. It's my "Budget" Earthroamer! I have on ought room on the overhang for two 100 watt panels. I'm thinking an aluminum tilting frame that if need be I could remove and remote over if in the shade. Looking at wintering boo docking in places like Yuma. Last month it's been -27 to -35 here! And I'm planning to be a snowbird in a couple years when I retire. Just got the truck this fall and project will likely take two years to complete.
 

rruff

Explorer
Yuma was my favorite winter spot back in the day. North of town, close to the river. Warmest place in the west in winter.

With the cost of panels being so reasonable, I'd put a 250-300W panel on the roof, fixed and flat, with an extra folding unit. Make them both 24v and use a MPPT controller and you'll be in good shape.
 

martnH

Member
The alternator is so much more powerful than any possible solar panels on a car....

So you won't need the solar input when the car is running.

For me, I will always prefer portable solar panels Because of this reason

Sent from my LG-H870DS using Tapatalk
 

Joe917

Explorer
Fatboyz Your roof is pretty high. This makes access to tilt a panel a PITA. go flat and add an extra panel.
Rayra Complicated is anything that does not take care of itself. Flat panels are always working, even when driving. Portable or slide out panels have to be "deployed". Nothing complicated about tilting a panel, its just not worth it until you get way north in winter. These guys have a pretty good handle on it: https://www.gonewiththewynns.com/tilt-rv-solar-panels
 

Fatboyz

Observer
Fatboyz Your roof is pretty high. This makes access to tilt a panel a PITA. go flat and add an extra panel.
Rayra Complicated is anything that does not take care of itself. Flat panels are always working, even when driving. Portable or slide out panels have to be "deployed". Nothing complicated about tilting a panel, its just not worth it until you get way north in winter. These guys have a pretty good handle on it: https://www.gonewiththewynns.com/tilt-rv-solar-panels
By add an extra panel do you men 3, 100 watt instead of two? Flat sure would make mounting easy! Curious why some suggest going 24 Volt? When you link all the panels aren't you keeping the output 12V but increasing the amperage output?
 

rruff

Explorer
Curious why some suggest going 24 Volt? When you link all the panels aren't you keeping the output 12V but increasing the amperage output?

If you wire 12v panels in series you have 24V with the same amps. But it's better to just buy 24v. You can buy 300W 24v panels.

Higher voltage allows you to use smaller wire, or lose less energy in the wires. For the portable panel this can be important if you have a 50 or 100ft wire to position it where you want.

A MPPT controller will take 24v input, and optimize voltage and current for your 12v battery bank. They are much more efficient than other controller types (you'll get more out of your panels), but are expensive.
 

rayra

Expedition Leader
Yuma's a fun place in winter. Buttercup dunes to the west is a major off-road gathering Thanksgiving weekend and heavily trafficked in the winter months. Good dove hunting around there too. And Glamis is only a few miles north, for even more dune-running. Gets pretty chill out there at night though, but nothing like Alberta in winter. Better be IN the river in the summer though, 115F+ is common.

It would be easy to fashion some pre-set height extension brackets to raise one long side of a mounted panel to get your optimum angle, care with how you orient the vehicle when parking takes care of the rest.

I'm actually intending to use a 3-axis pivoting flat screen TV arm as a panel mount, within my rooftop mounting frame. I'll be able to uncage the panels and lift and orient them any direction to square them to the sun. Or undo a couple 1/4"-20 knob-handle bolts and detach the foldign panel for ground use out away from the shaded vehicle.
 

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