Off Grid Battery Sizing

Welcome to the forum TFTI.

First, just to clarify, is that 6,000 Watts * 14 hours per day = 84,000 WH per day = 84 kWH per day

Or is that 6,000 WH (6 kWH) per day, over 14 hours (day time or night time)?

If it is the first, then, at a minimum, you are looking at:

• 84,000 WH per day * 1/0.85 AC inverter eff * 1/48 VDC * 1 day storage * 1/0.50 maximum discharge = 4,118 AH @ 48 VDC battery bank

If this is a grow operation, you are pretty much stuck with power big (and power hungry) lights. If you have green houses, then you only need to add light in the morning/evening times (some have argued for nursery operations, that only need "some light" to extend the growing season, not "full sun" the whole time).

If your needs are otherwise (pumping water, moving air, running a cell tower, etc.)--Then you probably should review your loads and take a serious stab at conservation. Many people can cut 1/2 (or even more) from their electrical needs if they work at conservation (new Energy Star Equipment, turn stuff off when not in use, insulation, etc.).

In general, running a very large off grid solar power system (84 kWH per day is very large--That can power a very large home with full AC in Texas or Florida). Probably would need a proffesional installer if this is your first time and you don't have a lot of electrical/construction experience.

If it is only 6 kWH per day, that is reasonable small system that works well for DIY folks.

-Bill