A novel UV sensor-based dual-axis solar tracking system: Implementation and performance analysis

The application of photovoltaic (PV) systems has been increasing rapidly worldwide in the field of sustainable electricity generation. However, the efficiency of PV systems depends significantly on the orientation of solar PV modules. To enhance the efficiency of PV systems, previous studies focused mainly on the development of sensor based solar tracking systems using sun position sensors. In particular, they used light-dependent resistors (LDRs), which detect the visible light spectrum. However, LDRs have significant limitations (e.g., saturation of light intensity and ineffectiveness under low-visibility conditions) that can adversely affect the solar tracking performance. Utilization of ultraviolet (UV) spectrum captured by UV sensors displays the potential for overcoming the limitations of LDRs. This is owing to the enhancement of UV radiation by the cloud effect during overcast conditions and the capability of UV sensors. Considering this, we propose a novel UV sensor-based dual-axis solar tracking system to improve tracking movements and PV energy generation by utilizing the advantages of UV radiation enhancement and UV sensor capability. Four intensity signals of UV radiation obtained by UV sensors are compared and employed as inputs to the solar tracking system after it is implemented on a pseudo-azimuthal mounting structure, which is capable of following the sun trajectory through daily and elevation angles. A comparative analysis is performed to evaluate the solar tracking performance of the proposed solar tracking system with respect to that of a fixed flat-plate system and conventional LDR-based solar tracking system. The experimental results reveal that our tracking system increases energy generation (after accounting for the operational energy consumption) by 19.97% and 11.00% compared with the fixed flat-plate system and LDRbased solar tracking system, respectively. Moreover, the proposed solar tracking system performs effectively in terms of movement tracking under the tested conditions. Finally, the economic performance evaluation demonstrates that the proposed tracking system is profitable.