Grid tie inverter - closer to array or closer to meter?

[Lo_Volt]

I haven't yet run the numbers on voltage drop, but I figured before I do I ought to find out if code will prevent me from doing it anyway.  I intend to put an 8kW array about 50ft from my workshop.  The workshop is directly between the array location and the house with about 100ft between the house and the workshop. 
I'm deciding whether to put the inverter in my workshop and run AC back to the main panel or to put it near my main panel and run DC from the array to the inverter.  My question is whether NEC code allows the inverter to be that far away from the main panel and service entrance/meter?  Is there any restriction on the distance? 
As I noted, I haven't yet run the numbers on voltage drop.  Back of the napkin says the longer DC run will be lower loss as the mppt DC voltage of the array will be around 325 volts and the AC voltage, of course, 240 vrms.  Lower voltage AC will draw more current and thus incur greater i²r loss. 
The real reason though is that I want to take this opportunity to upgrade the power to my workshop.  Possibly to push it to a 100 amp supply (2 AWG).  That will mean the average losses in the AC will now be lower as I probably won't need wire that big for the DC (I'm guessing at #6 or #4). 
Questions? Comments? Suggestions? 

[freejuice]

 Hi-lo
 Sorry just had too....anyway I'm in the process of getting my grid tie system too....I have spoke to the building codes folks and they dont see any problem with my way of grid tying:
 I plan on having my panels on top of my work shop behind the house...which by luck would have it, faces almost true solar south.
 Anyway the panels will have the enphase inverters and the 220V AC will run about 100 feet to my disconnect and then about  another 30 feet to my house service panel. I plan on using 8 gage thhn in underground conduit to keep the losses to a minimum and to have at least 125% above actual amperage carrying capacity of the panels....my amp load will be around close to 18 amps.....22 panels of 210 watts each
 
Maybe I'm missing something here, but I have always thought that AC is far more effiecent in power transmission in regards to cabling size.... why not simply make all your longer runs  for AC power and purge your mind of impure thoughts regarding DC tranmission?
 

[kenl]

If you are using the power for your house there will need to be a disconnect for the re there. The inverter does not have to be mounted there though, only a means of diconnecting the ac between the inverter and grid. Google pv and the nec, http://photovoltaics.sandia.gov/puborder.htm and try this link.

kenny

[SparWeb]

I think the main concept to consider is that the inverter is not a "load" on a typical "branch circuit" as far as the NEC is concerned.  You should sort-of treat it as a "service entrance" instead.  Well maybe the NEC doesn't actually make it out that way, but my point is that you have to be careful not to consider the inverter to be like an appliance.  It's not.

8kW/325VDC = about 25 Amps.  If you're thinking of #4 wire for the DC, then the losses are probably going to be very small.  The ampacity is more like 50/60/70 depending on the type and if you go with aluminum or not.
Depth of burial, conduit protection, location relative to other services, driveways, etc. are important factors. 
Another thought:  wire insulation rating of 300V is probably not good enough.  Consider the open-circuit voltage of the array with the inverter disconnected - what's the maximum voltage that could occur?  You may be specifying an expensive type of cable for the DC runs.

I'm going to go with aesthetics in this case, just to start off:  Inverters are a bit noisy, especially under load, so if I had the choice of putting one (a big one) in my house or in the shop, I'd go for the shop.  It allows you to be more utilitarian with the installation, too.

I flipped through my NEC book and now I find article 705... 
The point of interconnections is required to be at the premises service disconnecting means. 
Meaning that you need a kill switch beside the breaker panel where you feed in AC, even if you have another kill switch beside the panel array.

... but the bulk of solar PV code is article 690.

[DamonHD]

Hi,

I know UK that regs may differ, but I can report that I have manual disconnects for my PV at the consumer panel, in the loft on the AC side of the inverters and separate DC breakers for the panel strings.

Seems like good practice to me.

Rgds

Damon