24v charger/inverter

3,000 Watt*Hours per day is a fairly large system... Especially if you are not running a refrigerator. Unless you are doing  a lot of water pumping (irrigation, etc.). Also, a 705 AH battery bank is pretty large--You might want to think about going 48 volt (fewer batteries in parallel, less voltage drop at high inverter current levels). If this is a cabin (part time, weekend), a large solar power system may not be the best investment at this time. A smaller system (run lights at night, power small stuff for "quiet time") and use a nice (quiet) genset (Honda eu2000i or similar) for moderate loads--And for big shop loads/construction, run a 5+ kWatt genset when needed.

But, anyway, using our rules of thumb for an off grid cabin/home and 3,000 WH per day. Battery is sized for 1-3 days of storage (2 days nominal) and 50% maximum discharge (longer battery life):

• 3,000 WH per day * 1/0.85 inverter eff * 1/24 volts * 2 days storage * 1/0.50 max discharge = 588 AH @ 24 volt

And to charge such a battery bank, between 5% to 13% rate of charge (solar)--5% for weekend/seasonal use, 10%+ for full time (9 months or more) off grid living:

• 588 AH * 29.0 volts charging * 1/0.77 panel+controller deratings * 0.05 rate of charge = 1,107 Watt array minimum
  
• 588 AH * 29.0 volts charging * 1/0.77 panel+controller deratings * 0.10 rate of charge = 2,215 Watt array nominal
  
• 588 AH * 29.0 volts charging * 1/0.77 panel+controller deratings * 0.13 rate of charge = 2,879 Watt arary "cost effective" maximum
  

So--As you see, the larger the battery bank, the larger array you need (regardless of loads). Note that many battery mfg. recommend 10% minimum rate of charge for their flooded cell lead acid deep cycle storage batteries. 5% is the smallest I would suggest.

And there is sizing the array based on your energy usage. Assuming a fixed array
http://solarelectricityhandbook.com/solar-irradiance.html

Wausau
Average Solar Insolation figures

Measured in kWh/m2/day onto a solar panel set at a 45° angle from vertical:
(For best year-round performance)

Jan	Feb	Mar	Apr	May	Jun
3.24	4.11	4.55	4.73	4.97	4.98
Jul	Aug	Sep	Oct	Nov	Dec
5.04	4.83	4.27	3.55	2.74	2.56

Toss the bottom three months (assume generator/not present):
3,000 WH per day * 1/0.52 off grid system eff * 1/3.55 hours sun (October) = 1,625 Watt array minimum (break even month)

If your usage is much closer to 2,000 WH per day--I would down size the system to the level--Assuming part time use. And use the genset more (when needed) for heavy loads (temporary, construction, etc.).

If/when going full time, then you could go with a larger battery bank/solar array/ac inverter. Yes--It is difficult and expensive to expand a solar power system (you cannot "expand" a VW bug into a 1 ton Pickup "easily"). Also, depending on the area, you may have to worry about theft too (small, fixed solar power system, inexpensive/easy to move back home genset). Possibly even figuring out how to secure your well pump too (in California, even well pumps have been stolen).

If you currently use the well pump for pressurization--You might think about filling a cistern and use a smaller R/V type pump to pressurize for sinks/shower.

-Bill