Error: Azimuth 0 differs Azimuthal Axis performance

Hello SAM team!

I identified today an error in my simulations. I'm simulating Detailed PV - No financial model for Campo Grande, Brazil (weather file from INMET attached) ( energyplus.net/weather-location/south_america_wmo_region_3/BRA//BRA_MS_Campo.Grande.Intl.AP.868100_INMET ).

My system is over a surface north oriented (azimuth zero), but when I simulate using the azimuthal axis in System Design instead of value 0 in azimuth, the results are different. I read the Help according it and, as presented there, for south equator places, the azimuthal axis is 0, but the results are a bit confusing. Can you help me how to solve this problem? I don't know if SAM is really suited for my simulations, or if I need to use azimuthal axis or azimuth zero for not present bad results and fake performance.

The file is attached in this message.

Thank you in advance!

Luiz

Hi Luiz,

If your system has a fixed array that does not move and is facing North, you should use the Fixed tracking option with Azimuth = 0.

If you system has a tracker that rotates around a vertical axis, then you should choose the Azimuth Axis tracking option. For this option, SAM calculates the azimuth angle for each hour as the tracker rotates, so you do not need to specify a value for the Azimuth input.

Best regards,
Paul.

Hello team, 

I´ll have to endorse Luiz's report.
After SAM set accordingly to the standards of a fixed tilt/azimuth system, using a 0° Azimuth and the tilt=local latitude (15°), ie, modules facing north with the local latitude as the tilt, it MUST result in higher energy yield annually than in a 180° Azimuth setting.

And this is not what´s happening. For some reason, it seems that the calculations are being made as if the solar PV is located in the north hemisphere and has a higher generation facing south (180°).

Something is really wrong, 

Even the Monthly energy production graph is showing an opposite result as the expected one. For our region (south of equator), it should have a lower energy yield in the months between May and August (winter solstice), and it´s not what´s happening, as you can check below, with its correspondent system design print: 

Hi Lester,

Could you attach a .sam file that generates the results you describe?

Best regards,
Paul.

Hello there,

Thanks for the usual assistence. 

Here´s the .sam file. 

Regards,

Lester

Hello there,


Thanks for the usual help !
I´m sending attached the .sam file.

Regards,

Lester
-16.688599°,-049.284685°