PVsyst has just released a fix (new in version 6.10) for the issue raised in previous posts about shading losses and tracking.  The developer has posted a nice description of the history of the problem and the new approach being used.  If you use PVsyst to model tracking systems, it would be worth your while to check this out.  The link is here: http://forum.pvsyst.com/viewtopic.php?f=30&t=694.  Thank you to André Mermoud of PVsyst for sharing this information and news.

The PVPMC is always looking to raise awareness of technical issues in the PV performance modeling community.  Please share issues that you feel may be of general interest to our growing community.  The PVPMC has 750 members and growing!