Abstract Despite the sun-tracking system maximising the annual yield of solar power generation, the inevitable parasitic energy losses from the sun-tracking mechanism related to range of motion should be considered. This paper presents a systematic approach to investigate the annual accumulated parasitic energy losses in photovoltaic (PV) or concentrator photovoltaic (CPV) system installed in a dual-axis solar tracker located at various locations with latitudes ranging from 45°N to 45°S. This approach allows the engineers to evaluate and to optimize the PV/CPV system performance by determining the least parasitic energy loss in the cases of fixed and non-fixed stow positions. The results show that the solar tracker with non-fixed stow position always has lower annual accumulated parasitic energy losses as compared to that of fixed stow position located in different latitudes.