Renewable energy-driven desalination technologies: A comprehensive review on challenges and potential applications of integrated systems

Despite the tremendous improvements in conventional desalination technologies, its wide use is still limited due primarily to high energy requirements which are currently met with expensive fossil fuels. The use of alternative energy sources is essential to meet the growing demand for water desalination. In the last few decades a lot of effort has being directed in the use of different renewable energy (RE) sources to run desalination processes. However, the expansion of these efforts towards larger scale plants is hampered by several techno-economic challenges. Several medium-scale RE-driven desalination plants have been installed worldwide. Nevertheless, most of these plants are connected to the electrical grid to assure a continuous energy supply for stable operation. Furthermore, RE is mostly used to produce electric power which can be used to run desalination systems. This review paper focuses on an integrated approach in using RE-driven with an emphasis on solar and geothermal desalination technologies. Innovative and sustainable desalination processes which are suitable for integrated RE systems are presented. An assessment of the benefits of these technologies and their limitations are also discussed. © 2014 Elsevier B.V. All rights reserved.

An overview of the status of RE-driven desalination technologies, with a focus on integrated systems, their promotion and potential applications, as well as their current technological and economic limitations has been presented in this review paper. Existing RE technologies can be combined with prevailing desalination technologies. Presently, technological and economic constraints hinder large-scale applications. Current research on RE technologies and mass production of these systems can reduce the cost of solar energy. Geothermal energy can provide an attractive option for desalination, in particular where low-cost, low-enthalpy sources are available (e.g., from shallow depth, produced water from hydrocarbon wells, from existing deep wells, residual heat from geothermal power plants). Offshore geothermal resources can be tapped using mature technologies from onshore. Furthermore, since the price of fossil fuels is increasing, RE-driven desalination will eventually become feasible for large-scale applications. RE-driven desalination is a sound technology for freshwater production at small- or medium-scale to supply remote off-grid areas. However, there is a necessity to improve the thermal performance and technical efficiency of these systems. Also there is a need to make modifications to conventional desalination processes to make them more suitable for integrated systems. The coupling of RE technologies with desalination systems will require significant additional R&D. This will help to facilitate market launch and market penetration with mass production at low cost. In addition, technical enhancement and development of innovative and energy-efficient desalination technologies such as AD and MD, which are more suitable for RE use, will help to establish new frontiers in the application of RE technology. A combined-cycle solar and geothermal powered desalination process can provide the most effective use of RE without the need for energy storage. Nomenclature AD adsorption desalination CAES compressed air underground heat storage CPV concentrating photovoltaic CRS central receiver systems CSP concentrated solar power CST concentrated solar thermo-electric ED electrodialysis FAO Food and Agriculture Organization of the United Nations GCC Gulf Cooperation Council GE geothermal energy GOR gain output ratio HDH humidification–dehumidification HFC heliostat field collector HTF heat transfer fluid IBM International Business Machines Corp KACST King Abdulaziz City for Science and Technology KAUST King Abdullah University of Science and Technology LCOE levelized cost of electricity LFR linear Fresnel reflector MCDA GIS-multi-criteria decision analysis MD membrane distillation MED multi-effect distillation MENA Middle East and North Africa MSF multi-stage flash MVC mechanical vapor compression MWt Megawatt thermal O&M operation and maintenance PDC parabolic dish collectors PDS parabolic dish systems ProDes promotion of RE for water production through desalination PTC parabolic trough collector PV photovoltaic RE renewable energy RO reverse osmosis SE solar energy SPT solar power tower SWRO seawater reverse osmosis UHCPV ultra-high concentrator photovoltaic