Seawater desalination has established itself as a cornerstone of water security in arid and semi-arid regions. Population growth, rapid urbanization, industrialization, and climate variability have significantly increased pressure on conventional water resources, making the use of non-conventional sources essential. Globally, installed desalination capacity has grown steadily over the past two decades, with tens of thousands of units in operation and daily production exceeding 100 million m³/day [1,2]. This expansion is particularly pronounced in the MENA region, which accounts for a majority of global capacity due to its structural water deficit.
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Technological advances have profoundly changed the economics of the sector. While thermal processes historically dominated, reverse osmosis (SWRO) is now the predominant technology, thanks to significant energy efficiency gains and a gradual reduction in unit costs [3,4]. Investment costs (CAPEX) for large SWRO units generally range between 800 and 1,500 USD per m³/day of installed capacity, depending on location, project size, and level of technological integration [4,5]. Recent megaprojects show a trend toward cost optimization through economies of scale, equipment standardization, and increased competition among international consortiums.
Operating costs (OPEX) are dominated by energy consumption, which can account for 30–50% of the total cost of desalinated water production [6]. Advances in energy recovery systems have reduced the specific energy consumption of modern SWRO units to approximately 3–3.5 kWh/m³, compared to over 5 kWh/m³ two decades ago [7]. Other major OPEX components include chemicals (antiscalants, coagulants, biocides), periodic membrane replacement, electromechanical maintenance, and skilled labor costs [6,8]. In economies with historically subsidized energy, the impact of energy OPEX has long been mitigated, but the gradual reform of subsidies and the shift toward more sustainable models make energy management strategic.
In this regional context, several Gulf countries have developed massive capacities exceeding several million m³/day each, with projects integrating power plants and desalination units in hybrid or standalone configurations. Public-private partnership (PPP) financing models and BOO/BOT contracts have facilitated the entry of international private actors while maintaining strategic public oversight [4,9]. Competitiveness in recent tenders has progressively reduced the average cost of produced water, sometimes below 0.5 USD/m³ for large units benefiting from optimized energy conditions [4].
Simultaneously, some North African countries have accelerated their desalination programs to reduce reliance on dams and overexploited groundwater aquifers. Ambitious programs aim to rapidly increase national capacity to several million m³/day by the end of the decade. Units of 300,000 m³/day have recently been commissioned, representing multi-billion-dollar investments and significantly increasing the share of desalinated water in urban potable supply. Official projections target over 5 million m³/day by 2030, which would make desalination the primary source of drinking water in certain coastal areas. These large investments bring the CAPEX profile of these countries closer to that of the Gulf states, although financing structures differ and budgetary pressures are more sensitive.
Beyond volumes and costs, the issue of local integration has become a key strategic focus. Local integration measures the share of value added produced domestically in the design, construction, equipment, and operation chain. In many historical projects, reliance on international suppliers was high, particularly for reverse osmosis membranes, high-pressure pumps, energy recovery devices, and advanced control systems. However, industrial policies are gradually fostering the development of domestic expertise.
Local integration first manifests in civil engineering and infrastructure work, which accounts for a significant portion of total CAPEX. National companies participate in building construction, prefabrication of metal structures, manufacturing of tanks, piping, and mechanical supports. Electrical panels, control cabinets, and wiring can also be locally assembled under license. These segments, although considered peripheral compared to critical components, contribute to increasing domestic value added and developing a specialized industrial base.
Another area of integration concerns chemicals used in membrane pretreatment and cleaning. Antiscalants, coagulants, and some biocides can be formulated locally when the national chemical industry is sufficiently developed. Local production reduces logistical costs and secures supply while promoting skill transfer in formulation and quality control. Similarly, the production of microfilters or prefiltration cartridges can be partially localized, even though primary membranes remain mostly imported from major international manufacturers [8,10].
Maintenance and operation are likely the areas where local integration is progressing most rapidly. The growing number of facilities creates a structural need for engineers, maintenance technicians, instrumentation specialists, and qualified operators. Universities and training centers are gradually adapting their curricula to meet this demand. Developing national competencies in performance diagnostics, energy optimization, and membrane management reduces dependency on foreign experts and lowers long-term OPEX.
Some initiatives also explore the integration of renewable energy to power desalination units, particularly through coupling with photovoltaic plants. This hybridization aims to stabilize OPEX against energy price fluctuations and reduce the sector’s carbon footprint [5]. While full integration remains technically complex due to renewable variability, advances in energy storage and smart management open interesting prospects.
Regional comparison thus shows differentiated profiles. Economies with substantial financial resources and long-standing desalination experience demonstrate advanced maturity, competitive unit costs, and structured local content strategies. Countries recently engaged in large-scale programs have high initial CAPEX but benefit from rapid learning and strong political will to industrialize the sector. Overall, the regional trend converges toward combined CAPEX and OPEX optimization through economies of scale, technological innovation, and increasing local integration.
In the long term, desalination competitiveness will depend less on initial investment costs and more on the ability of states to progressively internalize higher-value segments. Local production of intermediate components, formulation of specialized chemicals, advanced maintenance, and national engineering development are essential levers to transform desalination from a mere technical solution into a genuine industrial driver. Current trends indicate that desalination is no longer only a water security instrument but a strategic sector combining industrial policy, energy transition, and technological sovereignty.
References
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[3] World Bank. The Role of Desalination in an Increasingly Water-Scarce World. Washington DC: World Bank; 2019.
[4] Global Water Intelligence (GWI). Desalination Markets 2022. Oxford: Media Analytics Ltd; 2022.
[5] Caldera U, Bogdanov D, Afanasyeva S, Breyer C. Role of seawater desalination in a 100% renewable energy based power sector. Water. 2018;10(1):3. https://doi.org/10.3390/w10010003
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[7] Darwish MA, Al-Najem NM. Energy consumption by multi-stage flash and reverse osmosis desalters. Appl Therm Eng. 2000;20(4):399-416.
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[9] Fichtner GmbH. Power and Water Sector Technical Report. Stuttgart: Fichtner; 2019.
[10] DuPont Water Solutions. Membrane Technology Report. Wilmington: DuPont; 2022.
