The "correct" tilt in the more northern and southern regions as well in higher places is "enough so the snow slides off the panels". I built a barn with a roof

The "correct" tilt in the more northern and southern regions as well in higher places is "enough so the snow slides off the panels". I built a barn with a roof at the "correct" 36° angle specifically so that the panels - 36x400W - both produce the maximum amount during the summer months as well as shed snow without the need for manual intervention.