Tom Murphy shows in his excellent book on energy that over-tilting your solar panels by 15 degrees is a good idea (Table 13.2): https://escholarship.org/uc/ite

Tom Murphy shows in his excellent book on energy that over-tilting your solar panels by 15 degrees is a good idea (Table 13.2): https://escholarship.org/uc/item/9js5291m#section.13.4 https://escholarship.org/uc/item/9js5291m#section.13.4 Basically take your latitude and add 15 degrees and that'll get you good annual coverage.