Good price on local panles..but how and if can be used?

First Question: What is the Vmp-panel of your 250 Watt Panels?

For a ~37.5 Volt Voc-panel, the Vmp-panel (std conditions) would probably be around 32 VDC Vmp-panel

The Vmp (and Voc) of panel varies with temperature... And temperature fall below freezing, the Vmp/Voc rise... So knowing the max cold temperatures you expect is helpful.

As a first guess with a 100 VDC max input voltage, very roughly 2x panels in series would cover you pretty much down to well below 0F... Three panels in series (37.2 volts * 3 =  111.6 volts Voc-array-STD conditions... Too high for the 100 VDC Max MPPT controller input voltage...

And we need to know the Imp of the panels--Again roughly:

250 Watts Pmp / 32 volts Vmp = 7.81 Amps rated Imp per panel (guess)
1,400 Max array wattage

Using the numbers we have, the maximum array would be 2 panels in series.

60 amps PV input max / 7.81 amps per panel/2 panel string = 7.68 strings ~ 7 strings max PV input current
1,400 Watt max PV input / (2*250 Watt panel strings) = 2.8 ~ 3 (3 OK?) strings max (using 1,400 Watt array limit)

Note this is a 24 VDC input inverter--So, my first guess is a single panel with Vmp~32 volts is a bit low for a typical MPPT controller and a 24 volt battery bank (as panels get hot, Vmp and Voc fall). So you are pretty much limited to:

2 series panels * 1 string (500 Watt array) (2 panels)
2 series panels * 2 parallel strings (1,000 Watt array) (4 panels)
2 series panels * 3 parallel strings (1,500 Watt array) (6 panels) (slightly over panels)
2 series panels * 4 parallel strings (2,000 Watt array) (8 panels) (over paneled)
2 series panels * 5 parallel strings (2,500 Watt array) (10 panels) (over paneled)

We may have a bit of confusion over panels connected in series (increases voltage) and parallel (increases current)... 2 panels in series (64 VDC Vmp est) * 3 parallel strings (Imp-array amps)

I have not read the manual, and just taking a few quick guesses... Not sure why both the 1,400 Watt array limit and a 60 amp input current limit)... Anyway, that is my first cut at the numbers and configuration (and why).

I have to go now. Lets get the above numbers/requirements clear first, then we can talk about PV Array wiring length.

-Bill

If I understand you correctly, yes you could connect a set of three in parallel (2x sets), then connect those two in series and get the same voltage/current results...

However, we usually like to make the base sets as 2x panels in series, then connect those in 3x parallel strings. Each array that has 3 or more parallel strings usually needs a fuse or circuit breaker per string to prevent a shorted string from being fed too much current (overheating wiring, starting fire, etc.).

With 2s x 3p you would need 3x fuses/breakers total. (one fuse per 2x panel set).

With 3p x 2s, you would need 6x fuses/breakers total (one fuse per panel in this case).

Also, we are trying for as high as practicable array voltage--And lower array current. This allows us to use smaller wiring and/or send power longer  distances with smaller AWG cable (and save on copper costs).

For example, with your 2s * 3p array, that would be (note these are 235 Watt panels, not 250 Watts)

3x 7.9 Amps Imp = 23.7 Amps Imp-array
2x 29.8 volts Vmp = 59.6 volts Vmp-array

Generally as a rough starting point, we want a maximum of 3% voltage drop in solar wiring for minimal energy loss. Using a voltage drop calculator:

https://www.calculator.net/voltage-drop-calculator.html?necmaterial=copper&necwiresize=7&necconduit=pvc&necpf=0.99&material=copper&wiresize=0.4066&resistance=1.2&resistanceunit=okm&voltage=59.6&phase=dc&noofconductor=1&distance=200&distanceunit=feet&amperes=23.7&x=Calculate&ctype=nec

400 feet of 2 AWG cable is not cheap. A 500' spool is around $1,350 in my area. Plus you need to use conduit (for burial or find 2 AWG direct burial 2 pair cable).

You could look at (roughly) 1/0 Aluminum cable (its own issues).

Or you could accept higher voltage drop (6% or more?).

Or you could do a battery/inverter shed at the array, and send 120 VAC to your home instead (higher voltage, lower current, smaller cable potentially).

There are now solar charge controllers that take upwards of 600 VDC input voltage. You would put all of your panels in series to use a "high voltage" VDC cable run and save money there. (higher voltage solar charge controllers are usually not cheap).

In any case, before you purchase any hardware, do some different paper designs and see what works best for you.

Probably more questions than answers right now. Have you worked out actual load needs (Watt*Hours per day, amount of sun in your area by season, possible backup Genset, etc.)? Have you looked at surge/lightning protection (if needed)?

-Bill

With a 1 month per year cabin, it is a bit difficult to justify the solar hardware vs just running a (small/inverter type Genset)  when you need the power... Add a "smallish" battery+small inverter (for lighting, charging phone/laptop, radio, etc.) can work well.

And you do not leave a bunch of expensive equipment unattended for 11 months of the year (hate 5 finger discount, but is is out there). Just less to pack up and take home (Genset, battery, etc.) when the stay is over.

Your planned system is certainly large enough that cyou can run the Genset whenever you wish--However, you might want to run it in the AM/Daytime when you loads are greatest (guessing)--You cycle the battery less and keep the battery topped off for those days you did not get more gasoline (bad weather, etc.)/Genset failed to start/etc.

In any case, with LiFePO4 batteries--They are pretty much near perfect. I suggest that you cycle them between 20% and 90% full for best life. That would be an ideal discharge (between charging) of:

100AH * 24 VDC * (0.90 - 0.20 SoC) = 1,600 Watt*Hours per "ideal cycle"

Trying for 2,500 WH per cycle on a (100AH*24VDC) 2,400 WH battery is expecting "too much" (let along the aging/loss of capacity of upwards of 20% over time)... So running the genset twice a day/during periods of heavy loads (water pumping, cooking, etc.) to stay within battery capacity would help.

A 40 Amp charger is a bit large (100 AH battery is rated for 30 amps nominal charging, and probably 50 amp max charge/continuous loads).

100 AH / 40 amp charging = 2.5 hours from 0-100% SoC (lithium batteries are very charge efficient--And time of charge too--Not like Lead Acid that require around 2-6 hours of "absorb charging" to reach 100% SoC).

Another question... Larger inverters usually require more Tare Energy (inverter power wasted when turned on and no loads)... The two all in one inverters you suggested take 50 Watts Tare. While not a big deal for a larger system, it still adds up over time:

50 Watts * 24 hours per day = 1,200 WH per day inverter "just on"
1,200 WH / 24 VDC battery bus = 50 AH or 1/2 of your batteries storage capacity of 100 AH

Note: Not sure if you have 100 AH or 200 AH battery... I thought the first time I clicked the link it was 200 AH, but now I see 100 AH--So I may be wrong here.

If you only run the inverter "when needed", that is a possible solution. Another, if you want 24 hour per day AC power and usually run smaller devices (small fridge, laptop, cell charging, some AC LED lightning)--Having a (possible) second smaller AC inverter (such as 300 Watts) can cut your 24 Hour Tare losses by a bunch. This Morning Star brand has 3.9 Watts of Tare/Self Consumption losses or almost 1/10th that of your larger inverters:

https://www.solar-electric.com/morningstar-suresine-300-b-inverter.html
https://www.morningstarcorp.com/wp-content/uploads/datasheet-suresine-en.pdf

I like the Honda Inverter Generators (I have the older eu2000i version). Your Genset, I would like to suggest a maximum continuous loading of 80% (if you are in the mountains, you also have max power vs altitude deratings):

1,800 Watts max continuous * 0.80 derating = 1,440 Watts (or max VA--another discussion)

Your AC charger loaded (guesses, need mfg data or Kill-a-Watt type meter readings):

40 Amps * 29 VDC * 1/0.85 typical charger eff = 1,365 Watt (or VA) max estimated charger draw

1,800 Watts * 0.80 derating * 1/120 VAC output = 12 Amps suggested max continuous Genset load current (best life)

So still a good match with charger+eu2200i Genset. Limiting charging current to 30 amps would be a bit "nicer" to your 100 AH battery. Unload the Genset a bit (if high altitude/hot weather). And give you some extra power for 120 VAC loads (or just run the inverter for your 120 VAC and save the hassles of plugging loads into Genset AC power, etc.). You will not waste very much power running from the inverter while charging.

Not sure what to do with your 100 feet of 8 AWG cable... Putting in conduit really means you cannot run and pull cable when you are there. And copper thieves would love that much copper to sell or use themselves.

Getting outdoor/UV Rated cable (suggest black to be less obvious vs Orange) and just put it how when you are there 1 month of year and roll up/lock when gone. (sorry--I am getting paranoid in my old age--Years ago somebody stole everything from well pump to whole cabin for one poor sole). Just temporary bury for under paths and such. 

8 AWG should be fine for your use... Note that "over sizing" and "derating" for loads/time/temperature/altitude--All those "derating factors" quickly add up (I.e., 80% max suggested Genset loading, 85% efficient battery charger, 3% cable losses, 85-95% Efficient AC inverter, Tare losses, battery temperature/cycle life/capacity degradation/large AC inverter + small AC inverter for 24 hour operation, etc.).

It is nice to have a "well or over designed" system... But it can get costly). The numbers/ideas above are just starting/sizing suggestions. And help you to ensure that you have the most efficient loads you can find. It is almost always cheaper (in the long run) to have smaller/high efficiency loads and smaller power solar/Genset power system.

-Bill