#97550  by Nut17
 Sun Aug 02, 2015 2:17 am
Neville. All my panels are wired in parallel, so the only losses due to shading occur with the two panels closest to the awning roll and only early morning or late afternoon depending on the position of the van. That still leaves six more unaffected panels to get on with the job. My panels are 24v units controlled by an 80 Amp MPPT controller.
 #97607  by NeilV
 Sun Aug 02, 2015 10:39 pm
muzzanic wrote:On both of our vans I have fitted a controller per panel as well so that 1 shaded will not drag the other 1 down, Much easier of course if you only have the 2 panels like us, But when I fit a 3rd panel it will have it's own controller.

Murray

So is it then worth buying a small (cheap) controller for the second panel to avoid inter-panel issues?

For $25 this one will also do 24v and work 'ok'???
https://trademe.co.nz/925091061
 #97616  by Neddy
 Mon Aug 03, 2015 8:14 am
If the likelihood of either of the panels being shadowed is high, two separate controllers would be the way to go.
If the panels are well sited, a second controller is probably not worth the extra trouble or expense.

Neville.
 #98775  by Grant4747
 Thu Aug 27, 2015 8:39 pm
Interesting to read how the shadowing affects the panels soo much.
I'm thinking about upgrading to flexible 140w panels sometime as they kinda make sense to me covering as much roof as possible.
On saying that are they ok to stand on if the need arises, when mounted hard down on fibreglass roof with urethane?
I also had (a perhaps crazy) idea about flexible panels being mounted on something light but strong like thin aluminium sheet and use it like a sloped awning on the side facing toward the sun with two or three stays to hold it up.
When travelling you'd fold it down vertically.
Would look a little odd not to mention it would have to be up before the main door could be used or even mounted on the opposite side for that matter.
Just so you guys don't think I'm getting too carried away here I'm planning on living in it with as many of the creature comforts of home as will allow off grid.
Your ideas/thoughts are welcome.

Grant
 #98776  by muzzanic
 Thu Aug 27, 2015 8:59 pm
I totally get were you are coming from, However, It is always best to Keep it simple.

Having to set it up before you can use the side door doesn't fit into that line of thinking.

I'm sure that you can find enough space on the roof for 500+ watts if you try hard enough.

As for the Flexible Solar panels, They are ok, But when I talked to AA Solar they said you are better off to put on the Normal type panels if you can.

However they both have there place & if you need to keep the weight down or are much better suited to something that can bend, Then go for it.

I Myself would mount them on a made up frame ( Even if that was just core flute ) I'm told they work better when they can get ride of heat.

Murray
 #99478  by aklbob
 Thu Sep 10, 2015 12:38 pm
My understanding is that polycrystalline panels output reduces dramatically with shading over a portion of the panel, but monocrystalline are not affected as much.
 #99480  by BrownBear
 Thu Sep 10, 2015 12:52 pm
Mine is a glass panel (looks glass like anyway) but i do know that if i leave my TV dish up during the day it dramatically reduces it charging ability.Shadowing really makes a difference.
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