Water-energy nexus: desalination technologies and renewable energy sources.

Rapid population growth and industrialization have contributed to a dramatic decline in the supply of freshwater. As a result, desalination is an important choice to solve the global problem of water scarcity. Nevertheless, the hyper-saline by-product, the high capital costs, and the high energy demands currently met by fossil fuels are key obstacles to the widespread adoption of desalination systems. Furthermore, desalination plants powered by fossil fuels have negative environmental impacts due to greenhouse gases (GHGs) emissions. In contrast to fossil fuels, renewable energy is abundant and clean and is therefore a promising alternative for powering desalination plants. This is why the water-energy nexus is a crucial step towards a sustainable future. Therefore, the integration of renewable energy sources (RES) into desalination is very important. The main objective of this review to analyze and evaluate desalination technologies (thermal-based and membrane-based) and RES (solar, wind, hydropower, geothermal, and biomass) that could be combined as an integrated process. Social-economic factors, environmental concerns, current challenges, and future research areas for both desalination and RES are discussed.