I own a PV install business called Solar Si, and was disappointed with how bad H2K's PV modeling and documentation is.

None of the defaults (user specified, mono Si) are reasonable.  Standard rooftop panels aren't 13-14% efficient, they are 20-21% efficient.  As well the temperature coefficient is negative, not positive.

I could find no documentation on the azimuth field, so from experimentation I found it is not a compass direction.  It's an offset from south.  If they are going to use an offset, it would make a lot more sense to be relative to the direction the front of the house faces, since H2K already has that data.

I tried to upload a datasheet, but it was rejected as an attachment.  Instead here's a link to one of the types of panels I've used this year.

https://en.longi-solar.com/home/products/Hi_MO4.html

Ray,

Given your reference to magnetic declination, does that mean you use a compass to determine orientation?
When I'm checking my planned driving route to the client appointment, I flip google maps to sat view and note the orientation.

CACEA does have a PV guide that was being worked on.