Single-Pyranometer Approach for Diffuse Optimization in Solar Tracking Systems
Abstract
This study presents the development and field validation of a simplified optimization algorithm for single axis tracking systems (SATS) operating under diffuse irradiance conditions. The proposed approach eliminates the need for complex meteorological stations or multiple reference cells, using instead a single pyranometer to monitor the clearness index (Kc) and control the trackers’ positioning. The algorithm commands the horizontal positioning of the modules whenever Kc remains below 0.3 for more than eight minutes, returning to standard tracking (ST) once the condition is no longer met. The methodology was implemented in a 5 MWp photovoltaic plant located in southeastern Brazil, where one of the ten inverter groups was used as the optimized unit with the proposed algorithm, while the others operated under ST. Over approximately one year of continuous operation, the system achieved daily energy gains of up to 5.49% and an accumulated improvement of 0.38% in energy generation compared to the reference groups. These results demonstrate the feasibility of applying a single-sensor diffuse irradiance optimization strategy in utility-scale PV plants, offering a cost-effective and scalable alternative to current tracking control approaches.
Keywords
diffuse irradiance optimization, single-pyranometer approach, solar tracking systems, clearness index, photovoltaic performance