Portable panels wire size

KD4UPL wrote:
#10 is too small. If your system is operating at 14.5 volts and your 2 panels are putting out 8 amps each you will have 27% voltage drop in 100 feet of #10. The first improvement would be to get an MPPT controller that will allow the panel output to be closer to it's Vmp of 17 volts. This would give you a 23% voltage drop. The next improvement, with an MPPT controller having a high enough input voltage, would be to run the panels in series. This would give you 34 volts at 8 amps which in 100' of #10 is about 6% voltage drop. (Isn't MPPT technology great!)
However, I normally try to design home solar systems with no more than 2% voltage drop in the DC cables. This would mean, even in series to MPPT, you need #4 wire.

Thanks for the info even though it is not what I wanted to hear. :(

So let me ask you this. From the link BFL13 sent me too I read where ktmrfs talked about using a 30 amp extension cord and tying the neutral and one of the other legs together to lessen the line drop. Then when I look at wire size chart I see that the diameter of 2 #10 AWG wires added together are almost equal the diameter of 1 #4 wire. If the diameters are similar does that equate out such that the current capacities are similar? The reason I ask is because I can buy 200 ft of stranded 10 gauge 2 conductor wire for around $70.00 while 2 conductors of 4 gauge 100 ft will cost around $200.00. Without considering code would 2 of the 10 ga cables help the line voltage situation?