Hard Panels, Flexible Panels, or Suitcase?

[bigsallysmom]

I want to install 200 watts of solar on a 17' high top class b van. The only flat surfaces on the roof have been taken up with two roof fans.  So it looks like I'm forced to go with portable panels.  

The van already has a 12v battery under the bed which powers lights, refrigerator, 12v outlet, 12v hwh and water pump. The refrigerator started working the other day after driving so I believe there is a solenoid out of sight somewhere.  I shall be replacing the old 12v with two 6v batteries.

I have yet to make any interior changes inside the van. My plans are to remove the third captains chair and build a 5' tall cabinet in its place. I can design it with a vertical slot for storing panels. When needed I'd pull them out and set them on the ground about 20' away from the rig.

I'd like to hear from folks who have a similar system. Were you happy dragging the hard solar panels out or did you go with flexibles? I'm getting of the age that I must consider weight and ease of getting it out of the van without tripping myself.  Or did you go with suitcase panels? I see the charge controller is on the underside of a panel, much too far from my battery and something to forget about when it starts to rain. On the renology unit, the controller can be unscrewed and moved. I'd bring it to under the bed and bolt it next to the battery.

So chime in folks with experience.

 

[Cammalu]

Just how much of a curve do you have? Do you have a photo


Sent from my iPhone using Tapatalk

 

[bigsallysmom]

Just how much of a curve do you have?  Do you have a photo

There's a curve in the front which looks very aerodynamic.  Then the sides don't go straight up.  They cut in 90 degrees for almost a foot before going vertical.  From the inside it looks like about two feet of width.

 

[Almost There]

There is always a way, somehow, to mount panels up top if that's the way you really want to go.

The flexible panels are kind of iffy in a lot of cases but may be doable if you're mounting them rigidly curved. One of the problems with doing that is that you're not allowing air flow underneath them. A lot of people have gone to installing a rack above the high top to allow panel mounting without using the flexible panels and allowing air flow.

I had a 100 watt suitcase with the external controller and found that it wasn't enough power for  my needs. I only use portable solar because I like to park in the shade whenever I can for my comfort but then can't get solar without being parked in the sunshine.

I sold the suitcase and got myself 2 - 100 watt Renogy Eclipse panels. They each only weigh about 17 lbs so they're lighter than the suitcase was by quite a bit. With a connector we made and a controller permanently  mounted inside the van in my electrical cabinet, I'm all set.

It's the best of both worlds AFAIC, I have portable solar, I park in the shade, I didn't have to drill holes in my roof nor put a IMO ugly rack up there. The panels are light enough for me to handle easily now and in to the future as I ...ahem...get older...

 

[bigsallysmom]

The backyard where I park the van is mostly shady and spouse is on me to not drive on the grass. So to keep the batteries in fine shape I'll park in a grassless area and run the panels to the only sunlit area.

 

[John61CT]

Flexible is lots easier, but don't expect more than 2-3 years.

As long as you don't actually break the framed type, they could last a decade or more. And they're cheaper.

 

[KathyC]

...Were you happy dragging the hard solar panels out or did you go with flexibles?

I loathe bringing the portable panel -- even though it works like a champ.  It's over 20 lbs. and inconvenient as hell.  I am going to go with flexible panels, but saving for the better quality Lensun ETFE panels that should be much more durable than aluminum.

 

[sephson]

When I first started putting my road tripper setup together, I got a small portable solar power system. What I found was that this portable system effectively chained me to my campsite when I had it out. Because the system was so easy to pick up and move, I was never comfortable leaving it unattended, so I would sit in my campsite waiting for some device to charge rather than getting out and exploring. I have recently installed 200 watts of solar on my roof. I haven't had a chance to field test it yet, but having everything bolted down and being able to lock whatever I'm charging up in the car should give me a lot more freedom to go out and do things when I'm on the road.

 

[MrAlvinDude]

Sounds to me like you two different scenarios;
- one when parked locally, and you just need the batteries topped off.
- another, when you are on the road, and need your solar to also give you power to run stuff.
Am I understanding this correctly?

So for the situation where you need to park in the shade, a 20-50W panel might actually be enough to keep the batteries fully charged?

For solar on the road, you might also combine some solutions. 
One choise could be to place a solar panel on top, at the front, and tilt it with the roof. It would mainly work, while the van is facing facing south. However, the tilt would give the panel 15 to 30% better working conditions, compared to a panel that was placed flat over the roof, while the van faces south.

Here is an example of someone who has chosen to place a panel so it follows the tilt of the roof.
http://justincredible.net/

 

[rm.w/aview]

Would four 50W tilting panels fit up there?

 

[MrAlvinDude]

For flat solar panels that are mounted on some kind of backing material, it is still an option to attach them to some sort of light weight frame.

Such a frame could be made from thin (max 1 inch) pvc pipe, or plastic L-angle lengths, or small alu L-angle lengths.  

This kind of frame could be much lighter than your typical suitcase frame, as it would not need to be the main support of the solar wafers. It would also not need to support (and keep straight) the glas/plexi front of a typical the suitcase design.  
But a light weight frame would still stiffen up the backing a bit. So I think this would also make a flexible panel last longer. 

And it might make a flat panel easier to place or stand on its own. 


Perhaps the frame could be designed so it would be easy to attach the panels to the roof.
Or a frame could be mounted on the roof, where it would be simple to slide in the flat panels. With the right design, this would make it easy to secure them so they could not as easily be stolen, as if they were just placed on the ground.


These ideas are focused on giving a high degree of flexibility to place the panels so they would collect as much power as possible. 
Still be light weight
And with options to be more secure than what is typical for a suitcase. 


Well, just a few thoughts anyway.

 

[Bohemian scout]

I have this same delimma. When I’m at my home base and not driving my van I need my battery to stay charged up. Installing solar on top of my van makes sense. However, when I’m camping and it’s hot I’d like to put a portable solar panel in the sun because of course I like to park in the shade. Is it a logical option to have both? How would that work with the charge controller? How many watts would I need for each separate system? I’m thinking I’d like to get the mounted solar first, like now. Then later buy a portable unit for hot weather camping when I park in the shade. Does anyone else do this? Is it feasible keeping it simple and not too expensive? Remember I’m a beginner and trying to understand so...KISS. Please and thanks!
Ps- I’m running a 18 qt dometic fridge, 12 volt van and charging a few devices.

 

[John61CT]

If just keeping a charged battery topped up when parked for months, even 15-25W is enough.

When actually in use cycling deeply, then your daily usage and solar inputs need to balance out.

Totally different scenarios.

 

[John61CT]

If you're going to park in the shade, don't bother mounting panels at all.

Put mounted and portable panels on separate controllers.

If shadows are moving and you don't feel like going out and shifting panels all day, the fewer panels per controller the better, ideally 1:1.

 

[Bohemian scout]

If you're going to park in the shade, don't bother mounting panels at all.

Put mounted and portable panels on separate controllers.

If shadows are moving and you don't feel like going out and shifting panels all day, the fewer panels per controller the better, ideally 1:1.

Here’s what I’m thinking of doing, tell me if it’s doable/logical or if another way would be better. Buy a 100w panel first to mount on top.  I’d like to be able to add 100w more later so would want the controller/wiring to handle that addition. Then I’ll see how things go and if I think I need the portable one for shade parking I buy one that’s has a charge controller built in.

 

[MrAlvinDude]

Hi Bohemian scout,
a step by step plan, so actual needs can be assessed along the steps, can indeed be a very good way to go.

And one charge controller for the top mounted panels, and another charge controller for a possible portable panel, gives optimal control of each panel type.

If you choose to buy one panel at a time (for roof mounting), try to make sure that they can still be the same type panel, or you might need a controller for each panel, as putting two different panels in series or parallel towards the same controller, is not a good way to go.

Choosing to start with the size controller and wiring, so they can handle your max build out (of the roof mounted panels), to include two panels, also sounds wise. And is not likely to add much to your up-front investment.
Should it turn out that one panel is enough, then the more 'powerful' wires and controller, will just minimize power loss in the wires and the controller will run cooler.
And that is not a bad thing at all 

 

[John61CT]

Built-in controllers svck.

And the SC needs to be at the bank.

 

[MrAlvinDude]

[font=Verdana, Arial, sans-serif]I guess I should also consider my battery, can it handle what I want? [/font]

Yes, that would be wise  

You can add up the amps (A) or watts (W) that each unit uses, and note for how long each unit will be running.  This can then be converted into a number of amp hours (Ah) that needs to be in the battery. 

Some units will say how many watt they use, other devices will directly say how many amps it uses. On a 12V system, watt is converted to an amp expression by dividing the watt number by 12.  So if it uses 25W, it is the same as 25W / 12V = 2.08 amp

Once you know your typical or average daily amp hour needs, then you can open the debate of how much overhead and buffer of amp hours on the battery is needed. 

Incidentally knowing something about your daily amp hour need, will also give you a very good indication if your 100W top mounted panel is likely to be enough. 


But perhaps one step at a time, with all the numbers, will make the decision feel more manageable?

 

[MrAlvinDude]

Hi John,

>"Built-in controllers svck."

hmmm.... is that not mostly a personal opinion?
They are quite likely to actually do their job, right?

Could it be that it will be better if the controllers are close, so the long wires between the controller and the batteries do not mess up the reading of the actual battery power?
Or that it will work best if the controllers are of the same type?

>"And the SC needs to be at the bank."
Not quite sure what an SC is?

 

[John61CT]

> They are quite likely to actually do their job, right?

On a scale of 1-5, built in are below 1.

A good controller (3-4) can be under $100.

> Could it be that it will be better if the controllers are close, so the long wires between the controller and the batteries do not mess up the reading of the actual battery power?

And voltage drop, between panels and SC higher voltages, thinner wire less V drop

and temp compensation

> Or that it will work best if the controllers are of the same type?

Not important, but easier for you. Plus redundancy.