A Low Cost, Fully Sensorless Dual Axis PV Tracker Using Astronomical Ephemerides and Discrete Actuation

Solar tracking systems can significantly increase photovoltaic (PV) energy production; however, conventional solutions often rely on sensors, feedback control systems, and continuous actuation, increasing cost, complexity, and maintenance requirements. This study presents a fully sensorless dual-axis solar tracking system that combines astronomical ephemerides with ZIP-code-based geographic localization to determine the optimal orientation of PV panels without optical, irradiance, GPS, or positioning sensors. The proposed approach employs discrete actuation to minimize mechanical movement and reduce energy consumption while maintaining high tracking accuracy. Simulation results, supported by experimental validation of the tracking mechanism, indicate that the proposed tracker increases daily energy output by approximately 56.65% compared with an equivalent fixed PV panel, while the energy consumed by the tracking mechanism represents only 1.17% of the additional energy generated. The analysis further demonstrates that tracking intervals between 1 and 2.5 h provide an effective compromise between energy production, actuator energy consumption, and mechanical wear. In addition, the system remains highly effective with tracking errors up to 12°, highlighting its robustness and suitability for low-cost implementations. The results show that a simple open-loop control architecture can substantially improve PV energy production with minimal hardware. The proposed sensorless tracking strategy therefore offers a practical, reliable, and cost-effective way to improve PV system performance, particularly in remote and resource-constrained regions.