Shading/Solmetric Import Annual production reduced by too much?

Hello,

I am modeling a 70 kW array in chicago. Without shading the estimate is about 91,000 kWh.

In Solmetric my annual solar availability is 89%. This is on the roof of a highrise and only a small penthouse can cause shading.

Once I import the hourly solmetric file into SAM the production estimate drops to 62,000 kWh - a decrease of 32%!

I have carefully reviewed which skyline files are going into the shading analysis, wondering if anyone has any experience or advice?

I will attach the hourly shading export to this question, I am not sure how to interpret it yet.


Thanks,

Alex

Dear Alex,

I did a test simulation with the shading file you attached, and saw a 85% difference between results with shading and results without, which seems more in line with the "annual availability" value you report above.

Would you mind sending me your .sam file so I can see your other assumptions? You can either attach it to your original post by editing it, or [url=mailto:sam.support t=_self]email it to me[/url].

Best regards,
Paul.