Solar Energy For Application To Desalination In Tunisia: Description of A Demonstration Project

For southern Mediterranean countries, small-scale solar desalination might be the most economic solution for providing potable water to remote communities lacking access both to the electric grid and the national water supply infrastructure. However, these communities have significant solar energy potential, enabling the use of solar power for fresh water production. This chapter identifies the potential of solar energy for water production in Tunisian rural communities. Three pilot research desalination concepts based on solar energy are described and analysed: solar multiple effects distillation; reverse osmosis driven by photovoltaic panels; and membrane distillation. The first demonstration desalination plant, for supplying 300 inhabitants, is located at Ksar Ghilene, southern Tunisia: it uses solar energy to power a reverse osmosis desalination unit with a capacity of 15m3/day. This chapter gives an analytical description of the plant components and reports experimental results for a 6-month operating period. Several problems challenges remain unsolved (e.g. brine rejection, low efficiencies, high cost). For this reason more research is required to optimise the technical and operating parameters and to improve the economic feasibility of the process.