Optimizing long PV cable runs

[Kent0]

It is good to plan you system for future expansion. If you wire the modules in series strings of four modules, you won't want six modules on a pole. You'll need another pole with four modules or a pole with eight modules.

By "polar" do you mean a tracking mount?

[vtmaps]

Have you thought about building a small power shed near the panels for the batteries and inverter?  You could send 120 or 240 volt AC down the 250 ft cable to your house.
--vtMaps

[Westbranch]

The only concern about having 4 panels on each array is the challenge of adding 2 additional panels to each array to expand the capacity and to keep the array's balanced.  Existing panels are about 1.5 m^2 each.  Going from 4 to 6 panels/mount creates some incremental mechanical design challenges to overcome (weight, snow load, etc.).. clivusmul.

have you considered 3 arrays?

[clivusmul]

Absolutely... I think any balanced expansion would require one additional array.  4 large panels is about the limit for a cost effective polar type mount (one costing less than $600+/-).  6 or 8 panels gets pricey plus the mast tubing goes to 6" Sched 80, cross tubes and etc. get pretty heavy too.  The problem with my best site (best sun exposure) is that it is a ways up a hill with no 4X4 access that is reasonable.  Hauling 110 # batteries X 8 to a remote shack makes the cost of a 4-4 AL URD look inexpensive...

Thanks to all for the inputs and replies... clivusmul

[David]

I would not worry too much about the wire loss.  I just purchased 8 KD 315 panels ( ~50V VOC, ~40V MP, min. winter temp -50F) and will be placing them 4 in series using a Classic 250 to a 48V battery bank.  The two arrays will be approximately 500 ft away and I was able to pick up a roll of 8 gauge underground feeder cable on e-bay for a fairly good price.  The copper prices are crazy compared to what they were 8 years ago (I put in my first array 250ft away using copper 1/0 which was  cheaper then the 8 gauge is today).  I will have about 5% line loss but more then make up for it by having a lot more hours of sunlight per day during summer months. 

[cpm]

Have you thought about building a small power shed near the panels for the batteries and inverter?  You could send 120 or 240 volt AC down the 250 ft cable to your house.
--vtMaps

This is what I would do, if it could be done.
best approach. (if possible on site).