Old and New SAM - Packing factor

I was converting an old .zsam file to a new .sam file. I noticed that the .zsam file had a section to input the "packing factor" and I could not find it in the new SAM (after hours of trying to locate it). Because of this, the land size is different and I get different results with the same inputs everywhere else.*
*The packing factor is located in "Array" in the old SAM(.zsam) under "Land Area".
The packing factor is in the "Help" sections in the new SAM where I attempted to seek help locating it (with no luck).

I have another question regarding the monthly soiling loss as well. What units do you use? Is it a percentage? It isn't clear what I should input.

Thank you for your help.

Hello,

We removed the packing factor input starting in SAM 2014.11.24 because it was causing confusion with the ground coverage ratio (GCR) input. Older versions had inputs for both, but they were completely independent so you could have land costs that were not consistent with the GCR. The term "packing factor" is also potentially misleading in the context of photovoltaic systems because it is also used to describe the density of cells in a module.

The current version of SAM uses the GCR for self shading and to estimate the land area required for the array.

At the bottom of the System Design page, you'll see values for "Estimate of Overall Land Usage." SAM estimates the land area in acres required for the array based on the total module area and GCR, which is an input just above it under "Tracking and Orientation."

On the System Costs page, you can specify land-related costs in $/acre based on that calculated estimate. If the estimate is not correct for your project, you can specify the land cost using one of the other units (% of direct cost, $/Wdc, or a fixed dollar amount), or any combination of them.

Best regards,
Paul.

Thank you for the response.

I have another question. Is there a section of "Depreciation" in the old SAM? In the new SAM, it is under Financial Parameters. However, I cannot find this section in the old SAM.

Hello,

Depreciation is on its own page in some older versions of SAM (specifically I am looking at version 2014.1.14)- the Depreciation page. The depreciation page is not found in the Residential model because it does not apply to homeowners.

Hope that helps.

Regards,
Janine