What is desalination?

Water scarcity threatens communities worldwide as climate change disrupts weather patterns and population growth strains our limited freshwater supplies. While water covers over 70% of the planet, less than 1% is available for human use. As droughts linger and groundwater reservoirs deplete, seawater has become an increasingly critical resource. 

Desalination makes that resource usable by filtering dissolved salts and minerals from seawater to produce fresh, potable water. The process has long been essential in regions where traditional freshwater sources are insufficient, and its importance is growing fast. According to Fortune Business Insights, the global desalination technologies market was valued at $27.8 billion in 2025 and is projected to reach $59.34 billion by 2034. The Middle East alone is expected to spend more than $25 billion on desalination capital expenses between 2024 and 2028, according to a 2026 study published in npj Clean Water.

The sun has naturally desalinated seawater for as long as the oceans have existed, evaporating water to produce rain. Man-made desalination units have been in use since the early 1900s, when steam-powered ships carried evaporators to produce boiler water. Since then, the technology has matured significantly. According to the International Desalination and Reuse Association, global installed desalination capacity stands at roughly 109.4 million cubic meters per day. An estimated 300 million people depend on desalination for their daily water.

How desalination works
Two main processes facilitate seawater desalination: reverse osmosis and thermal desalination.

Reverse osmosis pushes seawater under high pressure through semi-permeable membranes. These membranes act as a filter, allowing water molecules to pass while blocking salt particles and other impurities. The result is clean, potable freshwater on the other side. Studies show that reverse osmosis now accounts for roughly 70% of global desalination capacity, in part due to its energy-efficiency advantages over thermal methods.

Thermal desalination distills saltwater by heating it to produce water vapor, then cooling and condensing the vapor to yield pure drinking water. This process is typically used for water and process streams with high dissolved salt content, where membranes would be less effective.
Hybrid systems combine both reverse osmosis and thermal technologies, allowing the benefits of each to be tailored to specific conditions.

Recent innovations continue to improve energy efficiency and reduce the cost of desalination. Veolia’s Spidflow® DAF filter andM&C filter protect membranes and shrink the physical footprint of seawater reverse osmosis plants. Veolia’s Smart Membrane technology uses artificial intelligence to normalize and predict the evolution of operational parameters, enabling predictive maintenance and reducing unplanned downtime.

Veolia’s latest reverse osmosis technology is the Barrel™, a desalination system delivered on-site as a ready-to-operate module. This compact, digital solution produces water compliant with all purity standards and is also suitable for water reuse, offering significant capital and operating expenditure savings.

Veolia’s global desalination capabilities
With 18% of the world’s installed desalination capacity built using its technologies, Veolia is the leading player in the desalination market. The company has planned, built, and supplied equipment for hundreds of desalination facilities worldwide, producing freshwater for municipal and industrial applications across more than 2,300 sites in 108 countries.

In April 2025, Veolia announced an ambitious goal to double its operated desalination capacity from 1.4 million cubic meters per day to 2.8 million cubic meters per day by 2030, while maintaining its global market share. Over the past 25 years, Veolia has driven 85% gains in energy efficiency and a 90% reduction in the cost of desalinated water.

Our team works with plant operators to provide solutions that mitigate risk, encourage proactivity, and optimize uptime. Veolia assesses membrane fouling in real time to anticipate performance drift and act before unplanned shutdowns occur. Smart Membranes’ predictive features optimize maintenance planning, and real-time data and indicators save plant operators valuable time. 

Powering the world’s largest solar-driven desalination plant
One of the most significant examples of Veolia’s desalination work is the Hassyan seawater desalination plant in Dubai, commissioned by the Dubai Electricity and Water Authority (DEWA) and ACWA Power. Veolia is engineering and supplying the facility’s core technology.

Located roughly 55 kilometers southwest of Dubai Creek, the Hassyan plant will have a capacity of 818,000 cubic meters per day, enough to provide drinking water to 2 million people. It is the second-largest reverse osmosis desalination plant in the world and the largest powered entirely by solar energy, with an energy consumption rate of just 2.9 kilowatt-hours per cubic meter.

The plant is scheduled to reach full capacity in 2027. It will increase the UAE’s total desalinated water capacity to 3 million cubic meters per day, part of a broader national strategy to reach 3.3 million cubic meters per day by 2030.

Taking desalination offshore
In January 2026, Veolia and SBM Offshore announced a strategic partnership to develop and deploy near-shore floating desalination units, a new model for delivering freshwater in water-stressed regions. The partnership combines Veolia’s reverse osmosis desalination expertise with SBM Offshore’s decades of experience designing, building, and operating floating offshore production systems.

Each floating production unit is designed to produce up to 100,000 cubic meters of freshwater daily, enough to serve approximately 500,000 people. The units offer several advantages over conventional onshore plants: they can be deployed faster, scaled to match evolving demand, and relocated as conditions change. Target markets include municipal water systems in coastal areas, mining operations, and heavy industry requiring reliable freshwater for lower-carbon operations.

Defining the next generation of desalination
As water scarcity intensifies worldwide, desalination will play a growing role in securing safe, sustainable water sources for communities and industry alike. Veolia has spent more than 50 years building its position as the global leader in this space and continues to push the technology forward, from AI-powered membrane management to solar-driven megaplants to floating offshore production. These developments align with Veolia’s GreenUp strategy to accelerate ecological transformation.

No single solution can resolve the planet’s freshwater challenges, but seawater desalination holds unique promise by tapping an abundant resource to meet a growing need.Reach out to a Veolia expert to learn more about whether desalination is a viable solution for your water challenge.