World estimates of PV optimal tilt angles and ratios of sunlight incident upon tilted and tracked PV panels relative to horizontal panels – Stanford

“A critical parameter for installing fixed-tilt panels is the tilt angle, since PV panel output increases with increasing exposure to direct sunlight. Energy modelers also need to know the optimal tilt angle of a panel for calculating regional or global PV output in a given location or worldwide.”

Source: World estimates of PV optimal tilt angles and ratios of sunlight incident upon tilted and tracked PV panels relative to horizontal panels