Paper Title
Design, Techno Economic and Environmental Evaluation of a Small Scale Brackish Water Desalination Systems Powered by Solar Energy in the Arid Regions of Algeria.

Abstract
The southern regions in Algeria are suffering from fresh water shortage due to their climate severity and the geographic situation. These areas have access to brackish groundwater and significant potential of solar energy. The combination of solar energy with desalination processes, such as reverse osmosis systems, presents possible solution to satisfy the fresh water needs for the population living in these remote areas. This paper presents a technical and economic evaluation of a small-scale brackish water reverse osmosis desalination unit powered by solar photovoltaic systems for fresh water production under Algerian arid climate conditions. In the first part of this paper, a mathematic model has been developed for design and sizing the photovoltaic field, taking into account two configuration; power system with batteries and without batteries. The photovoltaic system model is coupled to reverse osmosis model to determine the overall system performance (water production, Specific Energy Consumption…) and an optimization is performed in order to determine the suitable configuration. In the second part, the economic feasibility study of use solar energy has been done using some economic parameters such as, Levelized Water Costs (LCOW) Net Present Value (NPV) and Internal Rate of Return ( IRR). The investigation also includes a discussion on the sensitivity of cost of unit of produced fresh water to some parameters such as the useful life of reverse osmosis system, cost of solar photovoltaic pannels and other associated parameters. The results of this investigation can be used also as indicators to identify the best locations for solar powered desalination plant implementation for fresh water production in Algeria. Keywords - Desalination, Brackish water, Solar Energy, Photovoltaic.