Self Shading Calculator no impact

Hello,

I'm facing the problem with Self Shading Calculator.

All the requirements to enable it have been met.
Simulation Results Does show self shading derate.
Although POA nominal is equal to POA After shading only. POA after shading ans soiling clearly shows soiling derate.
Losses summary show 0.00% losses due to shading.

Energy Yield is the same for both cases when self shading is on and off.

Hello,
SAM calculates self-shading losses differently for fixed arrays than for arrays with one-axis tracking.
UPDATE (OCTOBER 30 2015): AS OF SAM 2014.11.24 SAM USES THE SAME ALGORITHM FOR FIXED AND ONE-AXIS TRACKING ARRAYS.
As you know, for fixed arrays, the self-shading inputs are on the Array page. SAM calculates a DC derate factor to account for the reduction in the array's electrical output caused by self-shading. You can see the self-shading derate factor values in the hourly results. in SAM, self-shading for fixed arrays does not affect the plane-of-array (POA) irradiance values.
For one-axis tracking on the other hand, the self-shading inputs are on the PV Subarrays page, and SAM calculates a reduction in the POA irradiance incident on the array. You can see that effect by comparing the nominal POA irradiance to the POA irradiance after shading only in the hourly results.
Best regards,
Paul.

Paul,

I am totally on a same page with you.
The problem is that I'm using fixed tilt array and I still don't see any POA reduction in hourly results.
Although I see that shading calculator is working and SAM produces hourly shading derate that seems to be about right.

I have notice this issue initially with SDK and now with SAM.

I have attached sam project file to my initial post to illustrate the problem.

Thanks

That is correct. The self-shading model for fixed arrays does not reduce the POA irradiance, so you should not expect to see a reduction in the hourly results. Instead, the model reduces the array's DC output, which is why you see values for the shading derate factor in the hourly results. That derate factor applies to the array's DC output, not to the POA irradiance.

Thanks,
Paul.

Bump.

Have a similar problem. The self shading is not affecting the results at all. A look into the "Arrary Self Shading Derate" shows that the value is 1 even though there is self shading...

Dear masir,
Please see my reply to your other post:
sam.nrel.gov/node/69726
Best regards,

Paul.