Separate Solar Panels on gantry to lessen shadowing?

FullCircle

FullCircle

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Has anyone tried using multiple smaller solar panels on a gantry to lessen the effects of shadowing on output?
Would 4 50w panels be as effective as 2 100w?

I am think monocrystalline for the efficiency?
 
FullCircle said:
Has anyone tried using multiple smaller solar panels on a gantry to lessen the effects of shadowing on output?
Would 4 50w panels be as effective as 2 100w?

I am think monocrystalline for the efficiency?
Click to expand...

I dont like gantries, I have panels on cockpit roof, and swinging ones on my rails, works very well.
Not an expert but see no reason why 4 x 50 not give you similar, but I suspect someone will consider voltage drop x 4.
 
4 x 50W would, as you ask, be the same as 2 x 100W in terms of output. Equally, the gross effect of shadowing may be slightly less. However, assuming the backstay is the main culprit for shadowing, I'm not sure there's much advantage in four panels over two. I imagine 4 x 50W would cost more.
Additionally, if you wire either set-up in series, you can use smaller cables without suffering significant voltage drop. Many MPPT cotrollers, but I think only a few PWM controllers, would accept the increased voltage (a nominal 40V or 80V, depending on whether two or four panels).
 
FullCircle said:
Has anyone tried using multiple smaller solar panels on a gantry to lessen the effects of shadowing on output?
Would 4 50w panels be as effective as 2 100w?

I am think monocrystalline for the efficiency?
Click to expand...

That's exactly what I did, three 60W monocrystalline on the wheelhouse roof. I have no statistics but it's easy enough to keep two out of shade. To be honest we don't bother anymore and they still keep our 450AH bank charged though a British summer that's running a fridge 24/7.
 
macd said:
4 x 50W would, as you ask, be the same as 2 x 100W in terms of output. Equally, the gross effect of shadowing may be slightly less. However, assuming the backstay is the main culprit for shadowing...
Click to expand...

A backstay's shadow will have no effect worth mentioning. You need to put most of a whole cell in the shade to have an effect, and it's got to be the full umbra too, not just the penumbra.

I would expect a 100W panel to have two strings of the same cells as a 50W panel inside, so there is unlikely to be any advantage either way.
 
I have 8 80 watt panels on my gantry and cockpit roof.

My mooring faces north east to south west and I find the I get more output from the panels when I moor stern first north east ( southern hemisphere) I have a radar and wind generator plus aerials on the gantry but I found most of the shade comes from my mast and boom hence better output when mast is on the south side of my boat.

I have 4 regulators 2 on/off connecting direct to 2 banks of batteries (one each) and 2 PWM regulator connected only when we are on the boat (main battery switch off).

We are 30 degrees south so do get more sun then in the UK.

I also have a single 40 watt panel under my boom connected to my engine start battery connected all the time. The output of this panel is affected greatly by the mast and boom but still OK to keep my engine start battery charged OK
 
The possible advantage of 4x50 rather than 2x100 is that they can be wired as series/parallel giving 2 x 40v arrays. This gives a slight volt drop advantage if you have long cables between array and controller. I found that a better configuration than 4 in series and similar to 4 in parallel
 
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