Over 30 years off grid, not by choice when I started...
You used to have 2 HUGE issues, now it's down to 1.
Storage (batteries) were inefficient, expensive, short lived and constant maintiance.
That has mostly changed with Lithium. Not nearly the maintiance, much longer lived, much more efficient, but the cost is still up there.
The #1 issue I had was winter.
Short peak sun hours, overcast days etc.
You can't use or store what you can't produce.
No such thing as too many panels/over production, you MUST produce enough to operate on winter days or fill in the shortfall with other means.
You can't worry about 'Over Production' on longer, more direct sun days in summer. It's not 'LOSSES' when you simply can't use it.
Off grid, storage (batteries) are a close #2.
Unless you have 'Backup', which defeats the purpose of having solar PV, you will need at least a day or two minimum of storage. No sun days DO happen, and you need reserve storage capacity.
#3 on the list is REDUNDANCY.
Off grid, it's just YOU.
One BIG battery is fine for backup, but completely off grid batteries (plural) En Bank provide redundancy in the event of a failure.
Panel strings with charge controller for each battery is redundancy. Panel string or charge controller (ability to charge) can fail, you are redundant.
People talk about system, line losses. This small loss is INSURANCE you don't sit in the dark and the beer/bologna stays cold.
Off grid, MODULAR instead of combined units are a good way to go,
OR,
Chargers/inverters in parallel.
When (not *IF*) a combined unit fails, you will quickly learn about warrenty, repair times, parts availability, etc. Your inverter AND charger goes off to be serviced... Again, without redundancy you sit in the dark while the beer & bologna gets warm.
with redundancy you have reduced power.
The key part of that sentence is "You Have..."
If you built your own off grid system, you have the skills to add components in parallel with transfer switches.
Spare parts are always more useful when you flip a switch to activate them rather than having them on a shelf somewhere.
Flip the switches, remove failed components, plenty of time to get that serviced or replaced while up and running.
A capable DIY off grid system will cost about the same as an econo-box car, but last up to 30 years (so far).
Room for expansion if needed is the key.
For the cost of that econo-box you will have enough reserve to get through a few days without sun, be redundant, have enough production to charge on the shortest sunny day, etc.
In a full on, SHTF, grid down for weeks or longer.
See east coast ice storms, hurricanes, big tornado outbreaks, or just some moron that can't flip the switches correctly at a power plant/sub station...
Panels and batteries don't care.
DC power IS STILL POWER.
It's work you don't have to manually do, it's transportation, and it's refrigeration you can't do manually.
When was the last time you saw a hand cranked refrigerator?
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