Compass orientation and verticle angle are critical to getting optimum output from panels.
Have you tried a small PV test panel in your location? People are always surprised when they get far less than rated max output from panels.
Good luck.
Solar tracking units (esp dual axis tracking) in parabolic dish configurations generally are more expensive but worth it in the long run. With tracking, the dish is always pointed at the sun within a fraction of the optimal degree. As such, the vertical angle is less of an issue. Also, my roof gets full sun, dawn to dusk.