This paper intends to study the impacts of orbit parameters change and evaluate their importance in Electrical Power Subsystem (EPS) design. Two main objectives have been followed in this research: 1) understanding the impacts of the orbital parameters change and the mechanisms of their interactions with the EPS design and operation, 2) evaluation of the importance of their effects. To this end, a typical cube satellite has been considered in different LEO orbits, to investigate the impacts of variation in the main orbit parameters e. g. altitude and inclination angle. Then the sizing, operation and performance of power sources have been evaluated via comparing the results of in-orbit simulations of EPS operation. In addition, some indirect impacts of the orbit parameters change are evaluated, by analysis and calculation of the interaction between EPS and other subsystems such as Telecommunication and Telemetery (TMTC), Attitude Determination and Control Subsystem (ADCS) and Thermal Control. The results show how the sizing and operation of solar array and battery are under the influence of orbit parameters change via certain factors such as orbit period, duration and the fraction of eclipse to sunlit phases, received solar irradiance by solar panels, and received thermal fluxes from the sun. According to the acquired results, any altitude increment leads to have better margins in power source sizing but there is an optimum value for inclination angle from this point of view.