Article Open Access

The Potential of Salinity Gradient Energy Using Reverse Electrodialysis to Generate Electricity for Seawater Desalination Plants, an example from Western Australia

Clean Energy and Sustainability. 2024, 2(2), 10006;
Reza Rezaee *   
Western Australian School of Mines, Minerals, Energy and Chemical Engineering, Curtin University, Bentley, WA 6102, Australia
Authors to whom correspondence should be addressed.

Received: 24 Jan 2024    Accepted: 06 Mar 2024    Published: 13 Mar 2024   

(This article belongs to the Topic Collection Energy Recovery and Harvesting)


Seawater desalination plays a vital role in addressing the increasing global demand for freshwater. However, the energy-intensive nature of desalination processes and the generation of brine by-products pose environmental challenges. In Western Australia (WA), approximately 48% of freshwater is supplied by two seawater desalination plants employing the energy-intensive seawater reverse osmosis (SWRO) method. These plants are powered by a combination of renewable and conventional energy sources. Typically, the most efficient approach for desalination plants involves a blend of renewable energy sources. Salinity gradient energy (SGE) harnessed through the reverse electrodialysis (RED) system, which derives energy from mixing waters with varying salinities, has emerged as a potential solution. RED utilizes ion-exchange membranes to convert the chemical potential difference between two solutions into electric power. The net specific energy of SGE, calculated based on the Gibbs free energy associated with mixing seawater and wastewater, is estimated at approximately 0.14 kWh per cubic metre of brine for SWRO desalination plants. The combined SGE potential of WA’s two desalination facilities theoretically amounts to approximately 87.4 MWh of energy. However, due to the inherent limitations of the RED system’s current energy efficiency, only about 2.5% of the desalination plant’s energy requirements can be met through this technique. This paper addresses a significant gap in the literature by analyzing the technical and economic constraints of utilizing salinity gradient energy (SGE) through the reverse electrodialysis (RED) system for seawater desalination plants. This marks the first examination of its kind, shedding light on both the technical feasibility and economic challenges of SGE-RED application in this context. The scientific contribution lies in its innovative approach, integrating technical and economic perspectives to provide an understanding of SGE-RED technology’s potential drawbacks and opportunities. By identifying and tackling these challenges, this paper aims to pave the way for optimizing SGE-RED systems for practical implementation in seawater desalination plants.


Bahar H. Renewables 2020: Analysis and Forecast to 2025; International Energy Agency: Paris, France, 2020.
Ziolkowska JR. Is Desalination Affordable?—Regional Cost and Price Analysis. Water Resour. Manag. 2015, 29, 1385–1397. [Google Scholar]
Water-Technology. Perth Seawater Desalination Plant. 2008. Available online: (accessed on 20 November 2023).
Milne P. Climate-focused Water Corp Could Face $24m Bill after Failing to Power Desalination Plant with Clean Energy. 2021. Available online: (accessed on 12 November 2023).
Sanz MA, Stover RL, Degrémont S. Low energy Consumption in the Perth seawater desalination plant. In Proceedings of the IDA World Congress–Maspalomas, Gran Canaria, Spain, 21–26 October 2007.
Tristán C, Fallanza, M, Ibáñez, R, Ortiz I. Recovery of salinity gradient energy in desalination plants by reverse electrodialysis. Desalination 2020, 496, 114699. [Google Scholar]
Post J, Goeting CH, Valk J, Goinga S, Veerman J, Hamelers HV, et al. Towards implementation of reverse electrodialysis for power generation from salinity gradients. Desalin. Water Treat. 2010, 16, 182–193. [Google Scholar]
Pattle R. Production of electric power by mixing fresh and salt water in the hydroelectric pile. Nature 1954, 174, 660. [Google Scholar]
Qin T, Fan J, Zhang X, Feng J, Li C, Dong B, et al. Global Freshwater Discharge into the World’s Oceans Reached a Record Low Over Past Nearly 70 Years. 2022. Available online: (accessed on 10 August 2023).
Isaacs JD, Seymour RJ. The ocean as a power resource. Int. J. Environ. Stud. 1973, 4, 201–205. [Google Scholar]
Tufa RA, Pawlowski S, Veerman J, Bouzek K, Fontananova E, Di Profio G, et al. Progress and prospects in reverse electrodialysis for salinity gradient energy conversion and storage. Appl. Energy 2018, 225, 290–331. [Google Scholar]
Ramon GZ, Feinberg BJ, Hoek EM. Membrane-based production of salinity-gradient power. Energy Environ. Sci. 2011, 4, 4423–4434. [Google Scholar]
Post JW, Veerman J, Hamelers HV, Euverink GJ, Metz SJ, Nymeijer K, et al. Salinity-gradient power: Evaluation of pressure-retarded osmosis and reverse electrodialysis. J. Membr. Sci. 2007, 288, 218–230. [Google Scholar]
Zoungrana A, Çakmakci M. From non‐renewable energy to renewable by harvesting salinity gradient power by reverse electrodialysis: A review. Int. J. Energy Res. 2021, 45, 3495–3522. [Google Scholar]
Jang J, Kang Y, Han JH, Jang K, Kim CM, Kim IS. Developments and future prospects of reverse electrodialysis for salinity gradient power generation: Influence of ion exchange membranes and electrodes. Desalination 2020, 491, 114540. [Google Scholar]
Nazemi M, Zhang J, Hatzell MC. Harvesting natural salinity gradient energy for hydrogen production through reverse electrodialysis power generation. J. Electrochem. Energy Conv. Storage 2017, 14, 020702. [Google Scholar]
Xu S, Liu Y, Wang Y, Zhang M, Xiao Q, Duan Y. Influential analysis of concentration polarization on water flux and power density in PRO process: Modeling and experiments. Desalination 2017, 412, 39–48. [Google Scholar]
Dong F, Jin D, Xu S, Xu L, Wu X, Wang P, et al. Numerical simulation of flow and mass transfer in profiled membrane channels for reverse electrodialysis. Chem. Eng. Res. Des. 2020, 157, 77–91. [Google Scholar]
Culcasi A, Gurreri L, Zaffora A, Cosenza A, Tamburini A, Cipollina A, et al. Ionic shortcut currents via manifolds in reverse electrodialysis stacks. Desalination 2020, 485, 114450. [Google Scholar]
Brogioli D, Ziano R, Rica RA, Salerno D, Mantegazza F. Capacitive mixing for the extraction of energy from salinity differences: Survey of experimental results and electrochemical models. J. Colloid Interface Sci. 2013, 407, 457–466. [Google Scholar]
Lee J, Yoon H, Lee J, Kim T, Yoon J. Extraction of Salinity‐Gradient Energy by a Hybrid Capacitive‐Mixing System. ChemSusChem 2017, 10, 1600–1606. [Google Scholar]
Cath TY, Childress AE, Elimelech M. Forward osmosis: Principles, applications, and recent developments. J. Membr. Sci. 2006, 281, 70–87. [Google Scholar]
Micale G, Cipollina A, Tamburini A. Salinity gradient energy. In Sustainable Energy from Salinity Gradients; Elsevier: Oxford, UK, 2016; pp. 1–17.
Zhu Y, Wang W, Cai B, Hao J, Xia R. The salinity gradient power generating system integrated into the seawater desalination system. IOP Conf. Ser. Earth Environ. Sci. 2017, 52, 012067. [Google Scholar]
Gao H, Xiao Z, Zhang J, Zhang X, Liu X, Liu X, et al. Optimization Study on Salinity Gradient Energy Capture from Brine and Dilute Brine. Energies 2023, 16, 4643. [Google Scholar]
Zou Z, Meng S, Bian X, Liu L. A single-cell system of flow electrode capacitive mixing (F-CapMix) with a cross chamber for continuous energy production. Sustain. Energy Fuels 2023, 7, 398–408. [Google Scholar]
Yip NY, Brogioli D, Hamelers HVM, Nijmeijer K. Salinity gradients for sustainable energy: primer, progress, and prospects. Environ. Sci. Technol. 2016, 50, 12072–12094. [Google Scholar]
Jalili Z, Krakhella KW, Einarsrud KE, Burheim OS. Energy generation and storage by salinity gradient power: A model-based assessment. J. Energy Storage 2019, 24, 100755. [Google Scholar]
Veerman J. Reverse Electrodialysis: Design and Optimization by Modeling and Experimentation; University of Groningen: Groningen, The Netherlands, 2010.
She Q, Jin X, Tang CY. Osmotic power production from salinity gradient resource by pressure retarded osmosis: Effects of operating conditions and reverse solute diffusion. J. Membr. Sci. 2012, 401, 262–273. [Google Scholar]
Jianbo L, Chen Z, Kai L, Li Y, Xiangqiang K. Experimental study on salinity gradient energy recovery from desalination seawater based on RED. Energy Conv. Manag. 2021, 244, 114475. [Google Scholar]
Goh P, Ismail A. Flat-sheet Membrane for Power Generation and Desalination Based on Salinity Gradient. In Membrane-Based Salinity Gradient Processes for Water Treatment and Power Generation; Elsevier: Oxford, UK, 2018; pp. 155–174.
Li J, Zhang C, Wang Z, Bai Z, Kong X. Salinity gradient energy harvested from thermal desalination for power production by reverse electrodialysis. Energy Conv. Manag. 2022, 252, 115043. [Google Scholar]
Kang S, Li J, Wang Z, Zhang C, Kong X. Salinity gradient energy capture for power production by reverse electrodialysis experiment in thermal desalination plants. J. Power Sources 2022, 519, 230806. [Google Scholar]
Cipollina, A. Micale G. Sustainable Energy from Salinity Gradients; Woodhead Publishing: Sawston, UK, 2016.
Gonzales RR, Abdel-Wahab A, Adham S, Han DS, Phuntsho S, Suwaileh W, et al. Salinity gradient energy generation by pressure retarded osmosis: A review. Desalination 2021, 500, 114841. [Google Scholar]
Ribeiro L, Helfer F, Lemckert C, Sahin O. Australian Potential for PRO-Assisted Desalination. In Proceedings of the 21st International Congress on Modelling and Simulation (MODSIM 2015), Gold Coast, Australia, 29 November–4 December 2015.
Strathmann H. Electrodialysis, a mature technology with a multitude of new applications. Desalination 2010, 264, 268–288. [Google Scholar]
Smith JM. Introduction to Chemical Engineering Thermodynamics; ACS Publications: Lafayette, IN, USA, 1950.
Pitzer KS, Peiper JC, Busey R.  Thermodynamic Properties of Aqueous Sodium Chloride Solutions. J. Phys. Chem. Ref. Data 1984, 13, 1–102. [Google Scholar]
Vermaas DA, Bajracharya S, Sales BB, Saakes M, Hamelers B, Nijmeijer K. Clean energy generation using capacitive electrodes in reverse electrodialysis. Energy Environ. Sci. 2013, 6, 643–651. [Google Scholar]
Vermaas DA, Kunteng D, Saakes M, Nijmeijer K. Fouling in reverse electrodialysis under natural conditions. Water Res. 2013, 47, 1289–1298. [Google Scholar]
Forgacs C. Recent developments in the utilization of salinity power. Desalination 1982, 40, 191–195. [Google Scholar]
UN Warns of Rising Levels of Toxic Brine as Desalination Plants Meet Growing Water Needs; United Nations University Institute for Water, Environment and Health: Hamilton, ON, Canada, 2019.
Van Zalk J, Behrens P. The spatial extent of renewable and non-renewable power generation: A review and meta-analysis of power densities and their application in the US. Energy Policy 2018, 123, 83–91. [Google Scholar]
Ciofalo M, La Cerva M, Di Liberto M, Gurreri L, Cipollina A, Micale G. Optimization of net power density in Reverse Electrodialysis. Energy 2019, 181, 576–588. [Google Scholar]
Veerman J, Saakes M, Metz S, Harmsen G. Reverse electrodialysis: Performance of a stack with 50 cells on the mixing of sea and river water. J. Membr. Sci. 2009, 327, 136–144. [Google Scholar]
Giacalone F, Papapetrou M, Kosmadakis G, Tamburini A, Micale G, Cipollina A. Application of reverse electrodialysis to site-specific types of saline solutions: A techno-economic assessment. Energy 2019, 181, 532–547. [Google Scholar]
Geise GM, Hickner MA, Logan BE. Ionic resistance and permselectivity tradeoffs in anion exchange membranes. ACS Appl. Mater. Interfaces 2013, 5, 10294–10301. [Google Scholar]
Mei Y, Tang CY. Recent developments and future perspectives of reverse electrodialysis technology: A review. Desalination 2018, 425, 156–174. [Google Scholar]
Vermaas DA, Guler E, Saakes M, Nijmeijer K. Theoretical power density from salinity gradients using reverse electrodialysis. Energy Procedia 2012, 20, 170–184. [Google Scholar]
Vermaas DA, Saakes M, Nijmeijer K. Doubled power density from salinity gradients at reduced intermembrane distance. Environ. Sci. Technol. 2011, 45, 7089–7095. [Google Scholar]
Mehdizadeh S, Kakihana Y, Abo T, Yuan Q, Higa M. Power generation performance of a pilot-scale reverse electrodialysis using monovalent selective ion-exchange membranes. Membranes 2021, 11, 27. [Google Scholar]
Li J, Zhang C, Wang Z, Wang H, Bai Z, Kong X. Power harvesting from concentrated seawater and seawater by reverse electrodialysis. J. Power Sources 2022, 530, 231314. [Google Scholar]
Othman NH, Kabay N, Guler E. Principles of reverse electrodialysis and development of integrated-based system for power generation and water treatment: A review. Rev. Chem. Eng. 2022, 38, 921–958. [Google Scholar]
Tong X, Liu S, Crittenden J, Chen Y. Nanofluidic membranes to address the challenges of salinity gradient power harvesting. ACS Nano 2021, 15, 5838–5860. [Google Scholar]
Song D, Li L, Huang C, Wang K. Synergy between ionic thermoelectric conversion and nanofluidic reverse electrodialysis for high power density generation. Appl. Energy 2023, 334, 120681. [Google Scholar]
Feng Y, Zhu W, Guo W, Jiang L. Bioinspired energy conversion in nanofluidics: a paradigm of material evolution. Adv. Mater. 2017, 29, 1702773. [Google Scholar]
Daiguji H, Yang P, Szeri AJ, Majumdar A. Electrochemomechanical energy conversion in nanofluidic channels. Nano Lett. 2004, 4, 2315–2321. [Google Scholar]
Xin W, Jiang L, Wen L. Two-dimensional nanofluidic membranes toward harvesting salinity gradient power. Acc. Chem. Res. 2021, 54, 4154–4165. [Google Scholar]
Hsu JP, Lin SC, Lin CY, Tseng S. Power generation by a pH-regulated conical nanopore through reverse electrodialysis. J. Power Sources 2017, 366, 169–177. [Google Scholar]
Liu X, He M, Calvani D, Qi H, Gupta KB, de Groot HJ, et al. Power generation by reverse electrodialysis in a single-layer nanoporous membrane made from core–rim polycyclic aromatic hydrocarbons. Nat. Nanotechnol. 2020, 15, 307–312. [Google Scholar]
Lazard. Lazard’s Levelized Cost of Energy Analysis—Version 13.0; Lazard Zurich, Switzerland, 2019.
Turek M, Bandura B. Renewable energy by reverse electrodialysis. Desalination 2007, 205, 67–74. [Google Scholar]
Daniilidis A, Herber R, Vermaas DA. Upscale potential and financial feasibility of a reverse electrodialysis power plant. Appl. Energy 2014, 119, 257–265. [Google Scholar]
Kim H, Yang S, Choi J, Kim J-O, Jeong N. Optimization of the number of cell pairs to design efficient reverse electrodialysis stack. Desalination 2021, 497, 114676. [Google Scholar]
IRENA. Technology Brief; International Renewable Energy Agency: Masdar City, UAE, 2014.
Krakhella KW, Morales M, Bock R, Seland F, Burheim OS, Einarsrud KE. Electrodialytic energy storage system: Permselectivity, stack measurements and life-cycle analysis. Energies 2020, 13, 1247. [Google Scholar]
Simoes C, Vital B, Sleutels T, Saakes M, Brilman W. Scaled-up multistage reverse electrodialysis pilot study with natural waters. Chem. Eng. J. 2022, 450, 138412. [Google Scholar]
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