Design and field evaluation of a combined double-axis solar tracker

To improve solar energy gain by the photovoltaic (PV) modules, a novel double-axis solar tracker was developed in the present study. The proposed system worked based on both active and passive methods of sun tracking using electromotor and gas actuator, respectively. The electromotor oriented the module in the east-west direction based on the principle of the chronology of the sun, and in the north-south direction, the change in the gas pressure, due to the temperature change, activated a pneumatic cylinder to rotate the module. The evaluation tests were carried out at the different modes of tracking (including east-west, north-south and double axis). The results showed that the available solar energy on the PV module increased by 5.03%, 33.75% and 38.78% using the tracker at the north-south, east-west and double axis modes, respectively. This, finally, improved electricity generation of the PV module by 4.82%, 31.43% and 36.25%, respectively. Moreover, employing the tracker system led to an increase in operating temperature of the PV module. Based on the operating temperature of the module with the tracking system, it was proposed for using in the photovoltaic-thermal collectors. The designed system could track the sun trajectory with the accuracies of 0.6% and 8% in the east-west and south-north directions, respectively.