Usinas fotovoltaicas flutuantes como alternativa para a geração de energia e redução da evaporação em açudes do semiárido brasileiro

Abstract

About 28 million people live in the Brazilian semiarid and depend on 3,456 weirs as their main source of water supply. Water scarcity issues are part of the region’s history and Intergovernmental Panel on Climate Change (IPCC) indicates an increase in the average temperature associated with greater intensity and frequency of droughts periods, which leads to higher evaporation rate in its reservoirs. Floating photovoltaic systems (UFVF) could be used to mitigate water supply issues reducing the evaporation rate of water bodies such as weirs. Thus, this work aims to estimate the potential evaporation prevented and potential electrical energy generated by the installation of UFVF in weirs of the Brazilian semiarid using the Apodi-Mossoró basin, in state of Rio Grande do Norte as a case study. Three scenarios of the surface cover are considered for the weirs: 1) the area occupied by dead storage; 2) 50% of the total weirs area; 3) 70% of the total weirs area. Results show that the installation of UFVF over weirs would preserve 20.6 Mm³, 83.3 Mm³ and 124.3 Mm³ of water in scenarios 1, 2 and 3, respectively, and estimates the annual generation of 2.3 TWh, 8.6 TWh, and 12 TWh, respectively. The UFVF are more viable than the conventional photovoltaic plants because they reduce expenses with water trucks due to less weirs evaporation and due to the higher generation efficiency.