110510-1648 EDT

Cal.C10:

First questions are about how this PV system is structured.

1. Are all the PV panels tied together at the DC level at the array?

Yes-Strings of 14 Modules
If so then how large is the array in length and width in feet?

It varies- they are all 26' in width and either 60', 76' or 96' in length.
2. Are micro-inverters being used?

No-Array Strings to Combiners to DC Disconnect to Inverter-Inverter to AC Disconnect to Line side Bussing Tap ahead of the MCB
If not, then why not?

Huh? One Main Inverter
3. What is the distance from the array to where the power is used, stored, or whatever? Approximately

350 Feet-String Wiring to Combiner-this is the worst case scenario
4. Does the power have to remain DC?

See response to #2
5. What is maximum voltage and current level?

515.2 Volts DC. (Voc) [V] from 14 modules in one string. 7.68 amps @ Pmax (Imp) [A]
6. Are you concerned about the voltage drop within the array area?

Nope!
What is your background in electrical circuit theory?

Why are you busting my chops?:mad: It was a fairly simple question. I have found MANY answers (not all here in this website) that didn't require the follow up you have asked. My goodness, I input some simple data in my $60 Electri-Calc calulator, and it spits out an answer-not more questions...
Suppose your concern

(which it is not) is send DC over long lines, say 5000 ft between source

and destination. Consider 300 V maximum at the array, and a maximum current of 100 A. To hold the voltage drop to 30 V @100 A the total loop resistance, 10,000 ft, has to be less than 30/100 = 0.3 ohms, 0.03 ohms/1000 ft.

This would require ridiculously large copper wire. So change the DC to AC at the array, and then step up to 3000 V with a transformer. Retain the same voltage drop, 30 V but at the 3000 V level. Now the current is only 10 A, 30/10 = 3 ohms, or 0.3 ohms/1000 ft. This would get you to about #4 wire. Also consider the original 10% drop instead of 1%. Now the wire size could drop to about #14.

These are just to illustrate alternatives.

You need a clear definition of many parts of the problem.

What problem? I just wanted an Excel file...
Just a formula to plug values into will not necessarily provide a solution to a problem.

(Yes it does in my case) In fact as you work on a problem the definition of the problem may change. The problem might be what is the most cost effective means to transfer power from the array to its destination. This would include capital cost, operational cost, and the value derived from the product.

Basically I was looking for a formula which I can insert via OLE from Excel into my CAD drawing so I can prove I can use #12 USE-2 CU for my string wiring-that's all....
I knew there was a reason I strayed away from this web site for as many years as I did.
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