@cpaulgilman Before I move this to other module pages can you test this to see if you like the functionality. I'd prefer this over msgbox warnings as they could pop up often in system design. This won't have any effect on calculations at the moment.

I'm getting a callback error when I enable bifacial for the default Detailed PV / Single Owner case:

Could not evaluate callback function:cec_is_bifacial->on_change
[94]: reference to unassigned variable:check_clearance_height
[94]: error: _s
[94]: eval error in statement list

@cpaulgilman this should be cleaned up now but no rush on the review.

The callback issue is fixed -- thanks. Let me know when this is ready for a full review.

I believe it's ready for a full review, I will let you come up with better language for the message. I am happy to apply that language to all the pages once you have it.

Looks good for 1-axis tracking.

A couple of questions:

1. Should there be a check for fixed arrays?
2. Should there also be an SSC check on ground clearance? Right now, it is possible to enter negative values and zero for ground clearance, and SSC is not checking for insufficient clearance.

Looks good for 1-axis tracking.

A couple of questions:

1. Should there be a check for fixed arrays?
2. Should there also be an SSC check on ground clearance? Right now, it is possible to enter negative values and zero for ground clearance, and SSC is not checking for insufficient clearance.

1. For fixed arrays that distance is the distance between the ground and the bottom edge of the module so it would not apply here.
2. I can add SSC checks in the var table and potentially SSC notices, the actual calculations are not currently accounting ground interference.