A tool for the design of desalination plants powered by renewable energies

A unified approach for the evaluation of alternative renewable-energy-power ed desalination systems and their comparison on the basis of the economics of the associated investments is presented. The proposed method works out a preliminary plant design, evaluates the energy flows and calculates the wa ter cost and the expected water selling price. The energy needs of the desa lination processes and the energy production by the renewable energy techno logies are estimated using simplified models. The size and type of the back -up power units (energy storage, grid connection or diesel generators) are identified. The expected water selling price is estimated, taking into acco unt the water production cost and the investment profitability index. The c omputer-aided design tool that has been developed proposes technology combi nations that guarantee the desalination energy needs and provides the means to compare the alternative options on the basis of economic indicators. Re sults on alternative RE-desalination combinations are presented in order to select the optimum solution for a specific case study. The effect of criti cal design parameters on the water selling price is analyzed for a wind-pow ered reverse osmosis plant.