Ground Mount Panel direction question, 3 Arrays.

[doox00]

I am putting up 3 adjustable angle ground mount arrays, each with 10 400 watt bifacial panels, I am in Michigan. I am putting the 3 all side by side to each other. I am wondering if it is beneficial to put one aiming more SE, center one straight south and the other one facing more SW? I will have ~24k watts of panels total, the other ~12k worth on rooftops facing straight south and 130KW hours of battery storage.

 

[OzSolar]

I was chatting about this with a very smart friend the other day.

All of it facing due south gets you the most "potential" daily kWh but it may not get you the most "usable" daily kWh is what we came up with.

I think one needs to try to dig deep into thier system design to better answer this. For example, some solar farms are built facing to the west knowing that when the grid really needs thier energy is from 1PM until things start to cool off at sunset.

Our thinking was that having arrays of different orientations would allow you have a smaller battery bank. PV is cheaper than batteries plus it doesn't take up room inside your house or shop. 2X more batteries cost 2X's more and require 2X's more space inside.

You're in MI, perhaps you'd be better off with more east(ish) facing solar assuming you have more colder mornings than I do here in southern MO. The quicker you start producing more power the sooner your batteries start charging after the often long dark nights.

Not saying I'm right about any of that, just offering that I think that the design practices of 25 years ago when PV was $4/watt just for panels doesn't apply to today and it would interesting to dig deeper into that.

 

[Steve777]

You also may want to factor in your common weather patterns. For example: if afternoon/evening storms are common, tilting a bit E will improve AM sun on the panels before the storms roll in.