Tracker accuracy loss & Wind stow loss

[Amol Daware]

Hi all,

 

I’m currently working on large-scale solar PV projects using single-axis trackers with bifacial modules, and I had a couple of questions regarding how PVSyst handles certain tracker-related losses.

 

1. Tracking Accuracy Loss:
   Does PVSyst internally account for any energy loss due to tracking inaccuracies (like small misalignments or sensor/controller errors)? If not, is it recommended to include this manually under “Other Losses”? If so, what would be a reasonable default assumption?
2. Wind Stow Loss:
   In cases where trackers go into a stow position during high wind events, is there any way to model this loss in PVSyst? Or should this be estimated separately and added manually to the loss diagram?

 

 

Both of these can add up to 1–3% energy loss annually, and we want to make sure they are properly accounted for in our generation estimates — especially when working on PR guarantees or bankable yield assessments.

 

Would appreciate any guidance or best practices from the community or the PVSyst team.

[Linda Thoren]

Hello,

1. PVsyst does not consider any loss due to tracking inaccuracy and there is no general “other losses” parameter, though you could possibly add such a loss as a “soiling loss” for instance.
2. If wind velocity is available in the meteorological data, you can simulate wind stow behavior. You would define a wind speed threshold, and if the wind speed during a particular hour exceeds this threshold, the simulation would be done for the defined wind stow position for that hour.
   This would normally result in a less optimized tilt angle and thus less production, though it will not directly appear as a loss in the loss diagram.