Assessment of the Energy Gain of Photovoltaic Systems by Using Solar Tracking in Equatorial Regions

Abstract

Solar tracking is a major alternative to increase the electric output of a photovoltaic (PV) module, and therefore, improves the global energy collected by PV systems. Nonetheless, solar-tracking PV systems require more resources and energy than static systems. Additionally, the presence of cloudiness and shadows from near buildings may reduce the profitability of these systems. Therefore, their feasibility must be assessed in order to justify their application. In equatorial latitudes, the sun's movement through the sky is in the zenith East–West axis. It may be advantageous, since the best tilt in such latitudes is the horizontal. In these terms, the main objective of this research is to numerically assess the performance of a PV array with solar tracking and under typical operation conditions in equatorial latitudes. For this, the assessment of the solar resource in Quito was analyzed in first place. Then, the comparison between three solar arrays was studied to evaluate the feasibility of solar tracking (two-axes tracking, horizontal one-axis tracking, and horizontal fixed). Additionally, the impact of cloudiness and shadows in the system was analyzed. The results showed that the horizontal one-axis tracking is the most beneficial option for equatorial latitudes as the two-axes tracking system only surpasses the gains of the one-axis tracking marginally. Furthermore, the use of a strategy to place the PV modules horizontally in cloudy conditions seems to be marginally advantageous. Finally, the shadows created from neighboring buildings in the East and West of the system may reduce considerably the solar irradiation on the PV-array (not the ones in the north and south).