Dimensionamento de um sistema de iluminação a LED alimentado por painéis solares para melhoramento de iluminação pública no parque da Mozal

Abstract

This work addresses the design of a public lighting system using LEDs powered by solar panels, aiming to improve lighting in the Mozal park. Initially, the study location was described, highlighting its characteristics and lighting needs. Then, the components of the hybrid photovoltaic system were sized, including the selection of solar panels, energy demand assessment, battery bank sizing, inverter, and protective cabling. The chosen photovoltaic panel was the JAM54D40 model from JA Solar, with a power of 410 Wp, an open-circuit voltage of 37.82 V, and a short-circuit current of 13.95 A, due to its excellent cost-performance ratio and efficiency guarantee. The performance of these panels is significantly influenced by temperature and the irradiance incident on the photovoltaic cells. These aspects were meticulously analyzed using the PSimi tool to ensure a comprehensive understanding of how these factors affect the operation of the solar panels. To replace the conventional HPS luminaires with LEDs, the conditions of the original lighting design were maintained, ensuring that the new luminaires had technical characteristics equal to or superior to the existing ones. Among the analyzed suppliers, the 147 W LEDLUME XP3 luminaire from BekaSchréder was selected, which has a luminous flux of 23 496 lm. The energy consumption of the HPS lighting system was determined to be 7 kW and 8.4 kWh/day. With the replacement by LEDs, the new system presents a consumption of 4.116 kW and 49.392 kWh/day. The solar resource evaluation involved determining the optimal tilt of the panels (21 degrees facing true north) and using irradiation data obtained by the PVsyst tool, focusing on the most unfavorable period (June) with an irradiation of 4.52 kWh/m 2. day. Based on this, it was calculated that 11 modules would be required to meet the predicted load, occupying an area of 21.483 m2. The minimum inverter power was defined as 4.510 kW, opting for a 5 kW SUNSYNK model, with a maximum DC input power of 6500 V, PV input voltage of 370 V, nominal output power of 5000 W, and output voltage of 220 V The battery bank was sized with the necessary stored energy of 27.440 kWh/day and a bank capacity of 571.667 Ah, using LiFePO4 batteries model LPBF48200-H. The configuration resulted in 2 batteries in parallel to meet the total required capacity, maintaining the desired system voltage of 48 V. For the cabling, 4 mm2 and 35 mm2 cables were used as needed for current conduction in different sections, and the protective devices were sized to ensure system safety. The economic analysis of the project showed that the initial investment for the photovoltaic system is 2,300,192.87 MZN, with a simple payback of approximately 5 years and an estimated total savings of 8,707,167.13 MZN over the 25-year lifespan of the panels. Additionally, AutoCAD 2022 software was used to represent the system's single-line diagram.