It also is used to run some stuff in my shop but only when I am in the shop and I never have much running at any one time. My wind has been pretty good, but there are times when two or three days go by without enough to disallow the normal battery discharge to get down around 75 or 80%.
I don't think I follow what that means.
Wind seems to run in a cycle. 2~3~4 days of wind, then 2~3~4 days without much or any.
Solar is quite predictable.
It may have a couple days without much power, but it is predicted in the predictions.
Below, I am ignoring MPPT solar tracking controllers.
Myself, I am NOT very worried if the battery reaches 75%, and regularly.
Keep in mind, batteries will fail from age even if no usable power was removed from them. May as well use it while you got it!
My WAG is even 500W of solar would keep the battery SOG in the region you are looking for.
And with the combined power, there will be a high percentage of time it is an excercise in dumping excess power.
Might think about taking a couple small circuits off-grid? The laptop(s) is something obvious, because they have an internal battery, and give enough warning to move the plug from RE to grid. Maybe the UPS for the desktop computer? Both are small in comparison to the extra power you will have available, IMHO.
At a certain point with solar power, bigger does not cost a whole lot more.
The battery already exists, and most of the 'etcs' will still work fine.
Decent 48V solar controllers would cost about the same for 100W or 1000W.
Wiring cost difference is not much.
Hardware difference is not much.
Etc.
With a little bigger solar array, there will be more power to use on a daily basis, for very little extra cost.
Back to the original question, 'How many cells?'
In a 48V sytem, I believe 132 would be fine (33x4), because there is only one 'diode drop' to contend with.
Most common (AKA: inexpensive) PVs will come in 36 or 72 cell configurations, and that means 144 cells.
If a portion of any of the PV string could be subject to shading, 144 cells would be my choice.
Watch out for the S&H charges for larger PVs. Anything over about 80W per panel can come back to bite you in the butt when you get the freight bill.
G-