efficient placement=system size all components=initial investment
you might need that to determine usable output and total cost to calculate ROI, no?
It certainly contributes but the overall design is more complicated than that. My location is fixed, my days of sunlight are reasonably well known, so calculating the output is not difficult.
Where the additional cost for the initial investment comes in are things like battery sizing, location vs distance to batteries, inverters, control panels, etc. Does one create enough energy to only offset some of my electricity? Would two units take me off grid or would I have to get three?
It is a spreadsheet exercise that I need to look into.