In this study, energy and water production estimation on a large-scale time from Photovoltaic-Wind hybrid system coupled to a reverse osmosis desalination unit in southern Tunisia has been elaborated. The use of a hybrid system for desalination appears nowadays as a very promising solution for remote and arid areas. The produced energy is used for potable water production. For energy production, metrological data (wind speed, solar irradiance...) and steady-state models have been used. The obtained results show that the hybrid solution (solar and wind) gives an energy availability during the year, despite changing energy according to daytime, season and year. The reverse osmosis desalination unit powered by Photovoltaic-Wind hybrid system for producing potable water from brackish water is an appropriate solution to southern Tunisia (salinity about 6 g/l). For this, compositions of brackish feed water in Djerba region were selected. Double stage configuration in the desalination process using spiral modules is adopted extensively and validation of the steady-state models is presented. (C) 2011 Elsevier Ltd. All rights reserved.