Desenvolvimento de um sistema de rastreamento solar horizontal de um eixo de baixo custo baseado em microcontrolador

Abstract

This work presents the development and evaluation of a cost-effective horizontal single-axis solar tracking system based on the ESP32 microcontroller. The research was conducted in collaboration with Flex, a company located in Divinópolis, MG, with the primary goal of reducing the costs of the solar tracking system originally marketed by Flex by replacing the original controller, a PLC (Programmable Logic Controller), with a more affordable microcontroller. Throughout the development, Python algorithms were implemented to estimate daily irradiation curves, taking into account different conditions of photovoltaic plants (fixed structures and structures using single or dual-axis tracking) and geographic coordinates. Besides assessing the feasibility of solar trackers, the algorithms helped determine the most advantageous tracking methodology for solar alignment. The results from computer simulations indicated that using solar trackers can increase energy production by up to 30%, depending on climatic conditions and the type of tracker used. Regarding the module movement method for a single-axis tracker, higher generation was observed with movement based on the solar incidence angle, which represents the sun's position in the sky. Before testing the proposed controller in a real solar plant, a prototype was developed and tested under controlled conditions, with a peak power of 1.05 kWp. The analysis of the prototype tracker’s positioning curve showed that the ESP32-based system maintains adequate alignment of the solar panels throughout the day, validating the effectiveness of the tracking algorithms. Real experimental results, utilizing a photovoltaic mini-plant with an installed capacity of 109 kWp, indicated that the ESP32-based solar tracker generated between 17.51% and 30.42% more energy than a fixed plant, depending on weather conditions. The cost analysis demonstrated that the ESP32-based system has a significantly lower total cost compared to the PLC-based system, approximately 86% lower, making it an economically viable alternative for various applications, especially in plants with relatively low peak powers, between 1 kWp and 100 kWp.