LAUSR

Abstract 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 Mm³ of water in scenario 1, 83.3 Mm³ in 2 and 124.3 Mm³ 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.