Solar panel on roof
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- printmonkey
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Re: Solar panel on roof
Lights yes, but not a coolbox unless it's a compressor fridge ie Engel, Waeco, ARB etc.
US Import Vanagon GL Westfalia (Subaru EJ25)
Re: Solar panel on roof
Ok thanks, Ive just ordered them so hopefully they shouldn't be too longprintmonkey wrote:Lights yes, but not a coolbox unless it's a compressor fridge ie Engel, Waeco, ARB etc.

G
T25 1.9 Petrol 1985 Homebrew
- ghost123uk
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Re: Solar panel on roof
Mine is only 60 Watts and I find it does me OK, but only if it's a sunny day.gypo wrote: Will I be pretty much self sufficient on 80w?
Just so you know, most "ordinary" cool boxes use about 8 Amps of power, that works out at around 96 Watts ( 8A x 12V = 96W)gypo wrote: will it [80W] run a cool box and my led lights?
Got a new van, but it's a 165bhp T4 [shock horror] Accurate LPG Station map here
Re: Solar panel on roof
Cheers buddy, I've ordered 1 x 50w and 1 x 20w so 70w in total it was the only way I could fit them on the van. I could probably get another 20w one in there but it's already cost me £250 
G

G
T25 1.9 Petrol 1985 Homebrew
Re: Solar panel on roof
Would I have to use the load out on the controller as all my load is already sorted via the zig charger I assume. So is the load out in the controller redundant

Cheers
G

Cheers
G
T25 1.9 Petrol 1985 Homebrew
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Re: Solar panel on roof
Hi mate....I'm in the same boat as you on this...it would be quite complicated to rewire in order to route the 'outgoing consumers' through this 'load' circuit...I am assuming (and I can't see any reason not to believe this) that leaving this circuit redundant won't have any effect other than the load circuit will always read zero....although it would be NICE to see the balance between 'what is going in' compared to 'what is going out'.
Anyone know otherwise?
Martin
Anyone know otherwise?
Martin
1989 California 2.1MV
Re: Solar panel on roof
This is my thoughts exactly, I can't see a problem (unless I'm corrected) other than the load reading zero.California Dreamin wrote:Hi mate....I'm in the same boat as you on this...it would be quite complicated to rewire in order to route the 'outgoing consumers' through this 'load' circuit...I am assuming (and I can't see any reason not to believe this) that leaving this circuit redundant won't have any effect other than the load circuit will always read zero....although it would be NICE to see the balance between 'what is going in' compared to 'what is going out'.
Anyone know otherwise?
Martin
G
T25 1.9 Petrol 1985 Homebrew
Re: Solar panel on roof
Hi, similar to you due to space restrictions I have fitted 2 x 50w panels rather than one bigger panel, no performance downside that I can see. Charger controller connected directly to leisure battery not through zig unit and load connection not used as mine had max output of 10amps. Has been working great for last 18 months, will also charge the main battery if you switch zig to touring rather than on site.
You should take care in your panel positioning as you have mentioned a roof rack, even a small amount of shadow from this will have a disproportionate effect on panel output, something like 10% shadow will reduce output by 75% or more.
We have been very pleased with our setup which allows us to wildcamp for extended periods without the need to charge by driving.
Cheers phil
You should take care in your panel positioning as you have mentioned a roof rack, even a small amount of shadow from this will have a disproportionate effect on panel output, something like 10% shadow will reduce output by 75% or more.
We have been very pleased with our setup which allows us to wildcamp for extended periods without the need to charge by driving.
Cheers phil
1988 T25 Holdsworth Villa Hightop - AAZ conversion
- ghost123uk
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Re: Solar panel on roof
Hi Phil, not disputing you at all as I simply don't know, but
I wonder why that is ?
phil_b wrote: even a small amount of shadow from this will have a disproportionate effect on panel output, something like 10% shadow will reduce output by 75% or more.
I wonder why that is ?
Got a new van, but it's a 165bhp T4 [shock horror] Accurate LPG Station map here
Re: Solar panel on roof
ghost123uk wrote:Hi Phil, not disputing you at all as I simply don't know, but
phil_b wrote: even a small amount of shadow from this will have a disproportionate effect on panel output, something like 10% shadow will reduce output by 75% or more.
I wonder why that is ?
I've heard this too, from a friend who uses one on a boat, where masts and the like cause a lot of partial shadowing problems. Something to do with the cells being 'current sources' rather than 'voltage sources' perhaps. I'm no expert, but I read the following here.
The lowest solar cell current is the output current of the PV panel and the surplus current of each solar cell flows back through its diode.
"I'm a man of means, by no means....King of the Road!"
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- Oldiebut goodie
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Re: Solar panel on roof
I've got one sitting on my table that I was going to use for testing - my thoughts were to use the load terminals as a LVD device switching a relay to cut out all the leisure electrics when the voltage dropped too low. I have just got to get around to setting it up to see how well it would work.California Dreamin wrote:Hi mate....I'm in the same boat as you on this...it would be quite complicated to rewire in order to route the 'outgoing consumers' through this 'load' circuit...I am assuming (and I can't see any reason not to believe this) that leaving this circuit redundant won't have any effect other than the load circuit will always read zero....although it would be NICE to see the balance between 'what is going in' compared to 'what is going out'.
Anyone know otherwise?
Martin
1.6D 2019 VW T-Cross
200hp VW T6
1̶Y̶ ̶1̶9̶8̶7̶ ̶H̶i̶-̶t̶o̶p̶ ̶C̶a̶r̶a̶v̶e̶l̶l̶e̶
5̶0̶8̶d̶ ̶M̶e̶r̶c̶
200hp VW T6
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5̶0̶8̶d̶ ̶M̶e̶r̶c̶
Re: Solar panel on roof
Lots of info on the internet about the impact of shade on panels, but the easier for me to understand was that each cell in a panel can be thought of as a valve which is open to flow current when sunlight falls on it and closed when in shade. As panels are generally made up of a number of cells arranged in series like a long pipeline, shade on just one in that series closes the valve and effects flow in the whole series. The more separate series of cells in a panel or separate panels, each with a blocking or bypass diode, the less the impact of shade on the whole.
Probably a massive over simplification but helped me get my head around the impact of shade if not the science.
Cheers Phil
Probably a massive over simplification but helped me get my head around the impact of shade if not the science.
Cheers Phil
1988 T25 Holdsworth Villa Hightop - AAZ conversion
- djburns
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Re: Solar panel on roof
Can vouch for the problems of shading. Just come back from Cornwall. I have an 80w fold out panel which links through a controller direct to the leisure battery. Sunny interval type days keep things charged to run a waeco fridge, led lights, water pump etc. but NOT IF A GERMAN MOTORHOME THE SIZE OF A BLOCK OF FLATS WITH A DOZEN SURF BOARDS ON TOP PARKS NEXT TO YOU AND PUTS YOU IN PERMANENT SHADOW!
I also find if you are around the van it helps to just keep turning the panel to face the sun. Lying flat on top of the van reduced the charging rate. I am thinking of a flexi 100w panel to put on top of a large roof box I use on longer trips.
I also find if you are around the van it helps to just keep turning the panel to face the sun. Lying flat on top of the van reduced the charging rate. I am thinking of a flexi 100w panel to put on top of a large roof box I use on longer trips.
T25 Syncro 1990 2.1mv Holdsworth conversion