Dear Sir or Madam,
I am kindly writing to ask about the behavior of PV output during winter months at higher latitudes.
During winter months, for FIXED SYSTEMS, I have identified that after tilts of about 30°, the capacity factor diminishes in a convex trend, increasing its values towards 90°. In TRACKING SYSTEMS, this behavior is not happening.
The attached picture shows this behavior in a polar surface in which the length of the radius indicates the tilt and the circumference indicates the azimuth.
My question is which could be the reason why there is that convex phenomenon in the tilt and azimuth from tilt=30 to tilt=90?
Thanks in advance for your response