Dear masir,
Thank you for attaching your .sam file. That makes it easier for me to answer your question.
Before I get to the self-shading question, I found one problem in your file: You are using a weather file for a location in Australia (Location and Resource page), but the Azimuth for each subarray on the System Design page is 180 degrees, which means that the subarrays are facing south, away from the equator. For southern hemisphere locations, you should use an azimuth value of zero to orient the array toward the equator.
There are a couple of reasons you are not seeing any self-shading losses. The main reason is that the modules for each subarray are on a single row. For example, Subarray 1 has 56 modules with 8 modules along the bottom and 7 modules along the side, so all of the modules are in one row. If you change the number of modules along the side to 1, then the subarray would have 7 rows, and you would see the effect of self-shading in the results.
Once you have correctly configured the self-shading inputs, you are likely to see only a small effect because the subarray tilt angles are low (5 and 10 degrees), so the rows do not cast large shadows on each other. If you increase the tilt angle you should see more self-shading losses.
Finally, to see the effect of self-shading in the results, you can compare the POA total nominal irradiance to the POA total irradiance after shading to see the reduction in diffuse irradiance, and also look at the self-shading derates for each subarray. Note that "self-shading derate" applies to the DC output of each subarray rather than reducing the POA irradiance. That's because the self-shading model reduces the incident diffuse irradiance, but because the effect of self-shading on beam irradiance is non-linear, calculates a DC derate factor for its effect on the array's output.
Best regards,
Paul.
