diy solar

diy solar

Configuring panels for my inverter

is it better to use 7 panels x 2? this will give 347v and 7630w . This could be ideal for volts but is this over for watts?

The place i live in Lebanon varies between 35c max in summer and goes down max to -4c in winter

Below are the specs of inverter and PV

6x2 or 7x2?

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That's pretty good.
More wattage is better.
The mppt can curtail the overage on very sunny days.
And you will get better performance on cloudy days.
 
is it better to use 7 panels x 2? this will give 347v and 7630w . This could be ideal for volts but is this over for watts?
I dunno. If you want more power, then 7S2P is bigger than 6S2P. I cannot say if one is better (more efficient being better?). Both will work just fine.

With 2 strings, you can lengthen the charging day by pointing one string eastish and one string westish. May be handy, purely optional.

Voc temp compensation (certainly fine but i cannot resist a chance to do the math):

7S x 49.65Voc = 348Voc

temp coefficient (typical ~.35% per deg C change below 25C)

29 deg C delta

348V x 29 x .0035 = 35V increase at -4C

Still way below your 450V limit
 
When configuring 2 strings in parallel, what happens if 1 of the panels gets damaged during operation? how other panels behave and how inverter behaves? does it impact or damage other panels?
 
Even a -9°C low for an 8S string is 396.8Voc*34*.0035=47.2Vrise+396.8=444V. You have to get past a -13°C low before you get above the rated limit. More than good enough if you've got a quality SCC, which should have a bit of leeway so you can hit the limit and it will work as expected, not blow up if the setup isn't perfect at the limit.
 
Even a -9°C low for an 8S string is 396.8Voc*34*.0035=47.2Vrise+396.8=444V. You have to get past a -13°C low before you get above the rated limit. More than good enough if you've got a quality SCC, which should have a bit of leeway so you can hit the limit and it will work as expected, not blow up if the setup isn't perfect at the limit.
My other concerns if i configure in paralel, 2 strings, will be there any downside? what happens if 1 of the panels gets damaged during operation? how other panels behave and how inverter behaves? does it impact or damage other panels?
 
Worst case a damaged panel takes out half your generation capacity until you do something about it. An MPPT controller will adjust the voltage/current it draws from the panels to take the lesser of as much power as the panels can source or as much as the batteries/inverter can sink.

If the panel allows current to flow through it, but doesn't generate, you're much better off still - best case losing the equivalent of 1½-2 panels worth of power.
 
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