Análise de capacidade de geração e de aproveitamento de microrede baseada em sistema fotovoltaico em edifício residencial em Teresina-PI

Abstract

This work presents an analysis of the generation capacity and energy utilization of an off-grid photovoltaic microgrid designed for a residential building in Teresina, Brazil. The study is motivated by the regulatory changes introduced by Law No. 14.300/2022, which increase the operational costs of grid-connected systems, making autonomous configurations technically and economically attractive. The methodology included an aerophotogrammetric survey using a DJI Mini 3 drone, followed by 3D roof modeling in Agisoft Metashape Professional to define the available area for module installation. Based on solar irradiation data from CRESESB and assuming 5 peak sun hours, a system composed of 24 modules of 550 Wp (totaling 13.2 kWp) was dimensioned, estimating a daily generation of 66 kWh. The study evaluated key components of the microgrid, including MPPT and PWM controllers, LiFePO₄ and lead-acid batteries, off-grid inverters and electrical protection devices. The storage analysis showed that one day of autonomy requires approximately 15 LiFePO₄ modules of 5.12 kWh or 56 lead-acid batteries of 12 V and 200 Ah, highlighting the superior performance and lower physical footprint of LiFePO₄ technology. The generated energy is suitable for supplying essential household loads, such as lighting and low-power appliances, but insufficient for high-power equipment such as air conditioners and electric showers. The results indicate that shared off-grid microgeneration is a technically viable solution for residential buildings, provided that proper energy management, electrical protection and adequate component sizing are implemented.