PV Azimuth doesn't appear to work in Southern Hemishpere

Hi All

I've tried to model PV systems in QLD, Australia. we are south of the equator so the optimal azimuth should be North (0). 
However, no matter which cities weather data I use, South (180) always seems to generate more power. 

Also the shape of the load profile seems odd. With Solar you would expect higher generation in Summer (Dec - Feb) and lower generation in Winter (Jun - Aug). with Autumn and Spring being somewhere in between. When I use a azimuth of 180 (south), this is exactly the shape i get, however when I use a azimuth of 0 (north). its mostly flat with lower output in the summer months. The location I am testing is Mareeba, which is in far north Australia and thus close to the equator, so I can understand the load profile being somewhat flat, but not to this level.

I've sourced Australian weather data from  This Site , I suspect perhaps the fault lies with the data, as the SAM HELP PDF seems to recommend Azimuth settings on page 154.
unfortunately I do not know enough about the file types to find out where the issue might be.

Anyone else experienced similar problems, know of a potential solution, or perhaps where I might sourced different data?

I've attached the file, for perusal

Kind Regards
Bobby

Hi Bobby,

If you don't mind sharing a copy of a .sam file and .epw weather file that illustrates this behavior, it would be helpful for me to investigate.

In my tests using the detailed photovoltaic model with tilt = latitude for a southern latitude, I find that the total annual output is greater when azimuth = 0 than azimuth = 180.

Best regards,
Paul.

Hi Bobby,

Thank you for attaching the .sam file to your original message.

For a PV array with one-axis tracking, when the tilt angle is zero for a horizontal tracking axis, I would expect the system's output to be higher in summer months and lower in winter months. Tilting the tracking axis so that the array faces north in the Southern hemisphere has the effect of reducing the total monthly incident solar irradiance in summer months and increasing it in winter months compared to the horizontal tilt angle.

For example, from your .sam file and weather data, for Tilt = 0 and Azimuth = 0, you can see a clear pattern of higher output in summer months and lower in winter months:



Changing the tilt angle to 10 degrees with Azimuth = 0 slightly increases the winter monthly output and decreases summer monthly output.



As for the optimal azimuth angle, for a tilt angle of 10 degrees, and a range of azimuth angles from zero to 315 degrees, the maximum annual output is for an azimuth angle of zero:



I generated these graphs from the attached version of your file. For the Annual Energy vs Azimuth Angle graph, I ran a parametric simulation by clicking Parametrics under the Simulate button.

Best regards,
Paul.