Feasibility Study of a Reverse Osmosis Desalination Unit Powered by Photovoltaic Panels for a Sustainable Water Supply in Algeria

In recent years, reverse osmosis water desalination has developed rapidly and has become the most competitive and widely used technology in the world. The number of desalination plants is increasing rapidly as freshwater needs increase. Various membrane technologies have been developed and improved, including nanofiltration (NF) and reverse osmosis (RO), whose desalination costs have been relatively reduced. Therefore, this work proposes an experimental study for a small desalination unit based on RO generated by renewable energy, which is mainly suitable for arid regions or desert areas that do not have electricity and water and can be applied for emergency treatment to meet strong freshwater resource needs. In this study, to meet the drinking water demand, a reverse osmosis desalination system is designed and evaluated in order to improve and optimize its operation. This system has a daily capacity of 2 m3. We used brackish groundwater, which has been characterized as reference water, to produce synthetic water for different salinities until seawater. The analysis is based on data obtained from experiments carried out in the standalone RO pilot designed for the production of fresh water. For this purpose, we conducted relevant experiments to examine the influence of applied pressure, salt concentration and temperature on the RO membrane performance. The effects of different factors that affect the energy consumption in the RO desalination process were analyzed, and those with significant influence were explored. The effectiveness of RO desalination coupled with a photovoltaic (PV) energy system is shown. We found the recovery rate for system operation to be 32%. An optimization study is presented for the operation of an autonomous RO desalination system powered by photovoltaic panels. The energy produced by the PV system was used to feed two pumps forthe production of drinking waterwithanRO membrane, under the conditions of the town of Bou-Ismail. As results, a 3 kWp PV system was installed based on the energy demand. The design data have shown that a 3 kWp PV system can power a 1.8 W RO load given the Bou-Ismail climate. Energy consumption in the case study under Bou-Ismail weather conditions were analyzed. The desalination of brackish water at a TDS value of 5 g/L requires an energy of about 1.5 kWh/m3. Using seawater at a TDS value of 35 g/L, this value increases to 5.6 kWh/m3. The results showed that the optimal recovery rate for system operation was determined to be 32% for a feedwater salinity of 35 g/L, and 80% for a feedwater salinity of 1 g/L.