A hybrid renewable energy system as a potential energy source for water desalination using reverse osmosis: A review

The water needs of the inhabitants of Saudi Arabia are met by desalination powered by electricity generated from fossil fuel. Excessive burning of fossil fuels results in faster depletion and causes an adverse impact on the local environment. Reverse osmosis (RO) desalination based on a hybrid renewable energy system (HRES) has emerged as a cleaner alternative. The primary objective of this review is to assess the current status of utilizing renewable energy for small and large-scale water desalination plants. An overview of the expansion of domestic and global desalination plant capacities is presented with the evaluation of Saudi Arabia's renewable energy potential. Numerous studies on coupling various combinations of renewable energy sources to power desalination processes are reviewed. A comprehensive analysis of the trends and technical developments of PV-RO, Wind-RO, and hybrid PV-Wind-RO for a wide range of capacities over the past three decades is provided. Designing and modeling HRES-RO desalination systems using different combinations of renewable energy sources are thoroughly analyzed and the technical aspects of their performance are presented. The application of a range of optimization and sizing software tools available for conducting pre-feasibility analysis and the comparison of the available software tools for HRES-RO desalination are also presented. The study also demonstrated that the replacement of fossil fuel with renewable energy for desalination will significantly decrease greenhouse gas emissions. The review also highlights the effect of solar and wind profiles on the economics of desalination powered by renewables. The economic analysis indicates a significant decrease in the cost of water production by hybrid PV-wind-RO systems, implying good prospects for the technology in the near future. Finally, the study provides a flowchart depicting the steps involved in installing a hybrid PV-wind-RO system in KSA.