I don't know anything about rooftop solar mounting systems, I will show my ignorance here: I was imagining that perhaps you could attach the panels to rails running vertically rather than horizontally, to allow for convection airflow below the panels.
Or if the rails are horizontal perhaps they have holes in them to allow some airflow.
I'm sure this has been thought of and doesn't work some obvious reason I just don't know about.
Edit: As I expected, this has been thought of: https://solarstone.com/blog/natural-ventilation-and-effect-o...