Water-energy nexus: Floating photovoltaic systems promoting water security and energy generation in the semiarid region of Brazil

Floating photovoltaic systems could be used to mitigate water supply issues by reducing the evaporation rate of water bodies such as weirs. This paper aims to estimate the potential evaporation prevented and the potential electrical energy generated by the installation of floating photovoltaic systems in specific weirs of the Brazilian semiarid region. Moreover, an economic feasibility analysis is carried out regarding energy and water supply. A net present value approach was used to conduct this analysis. The software System Advisor Model was employed to simulate and compare the performance of two photovoltaic systems in the region: floating and ground-mounted. Three scenarios of the surface cover are considered for the weirs: 1) the average area occupied by dead storage of all weirs; 2) 50% of the total area of weirs; 3) 70% of the total area of weirs. Results show that the installation of floating photovoltaic systems over weirs of the Apodi/Mossoro basin would potentially preserve 20.6 Mm(3) of water in scenario 1, 83.3 Mm(3) in 2 and 124.3 Mm(3) in 3. The annual electricity generation estimated in scenarios 1, 2, and 3 is 2.3 TWh, 8.6 TWh, and 12 TWh, respectively. Financial results show that when energy and water cash flows are considered together, payback time diminishes, and the project becomes more economically feasible. (C) 2020 Elsevier Ltd. All rights reserved.