When the sea slakes our thirst: the history and future of desalination around the world
From age-old distillation methods to reverse osmosis, all the way to cutting-technologies, the global desalination market is growing at an astounding rate. An engineering and environmental challenge to provide a reliable water supply in places where water is scarce.
Desalination: alchemy from a distant land
Desalination is a process that allows for the salts present in seawater or brackish water to be reduced or even removed entirely, making it drinkable or suitable for agricultural and industrial use. This ‘alchemy’ was already well understood in ancient times: indeed, in his treatise Meteorology, which dates back to the 4th century B.C., Aristotle writes: “Salt water when it turns into vapour becomes sweet, and the vapour does not form salt water when it condenses again. This I know by experiment”. This type of desalination, which also occurs via distillation in nature (also known as ‘thermal desalination’), is based on the principle of evaporation by which heating a saline solution results in fresh water condensing, leaving the salty residue at the bottom.
From distillation to reverse osmosis: a necessary evolutionary leap
Up to the 1970s, this type of desalination was used almost exclusively, with the basic principle of evaporation remaining exactly the same, albeit on an industrial scale: vast quantities of seawater are heated, with the product of the resulting distillation then being collected. However, this process is extremely energy-intensive, as well as requiring a great deal of space. As of the 1980s, desalination based on reverse osmosis started gaining ground, gradually coming to replace thermal desalination almost completely as it consumes much less energy and can be performed in much more compact facilities.
How does reverse osmosis work?
The process of reverse osmosis is considered a mechanical one as the saline solution (seawater or brackish water) is subjected to high pressure - specifically, a level higher than the osmotic pressure of the solution (hence the name reverse osmosis) - and then forced through a semi-permeable membrane that allows the water molecules to pass through whilst retaining the salts. (Fisia Italimpianti – Reverse Osmosis (RO) Desalination plants).
New technologies with great potential have recently appeared on the market, such as direct osmosis and membrane distillation. However, transitioning from the experimental phase to the application and industrial phase involves lengthy turnaround times, and so these new technologies have not yet been applied outside of purely experimental conditions.
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The desalination market and its future prospects
The desalination market is coming on in leaps and bounds, requiring increasingly vast and high-performance facilities. It is estimated that the desalination system market is currently worth $1.68 trillion as of 2025, a figure expected to reach $2.57 by 2030 (Desalination System Market Analysis | Industry Report, Size and Forecast).
Desalination plants around the world today
There are currently around 16,000 desalination plants in operation worldwide, spread across 177 countries and capable of generating a daily total of 95 million cubic metres of fresh water. Just under half of all desalination plants are located in countries in the Middle East and North Africa, where the demand for water is high, the cost of energy is low, and the socio-economic conditions make sizeable investments a sustainable choice. Saudi Arabia is home to one of the largest in the world, the Jebel Ali Desalination Plant, which produces 636,400 cubic metres of water a day and which was Fisia Italimpianti helped to construct.
Australia and India also make extensive use of desalination, whilst in Europe, the country that harnesses its potential the most is Spain, with 765 facilities. In Cyprus, 95% of all water distributed for drinking is derived from desalination. Growing markets include the United States, Australia and Latin America, but desalination is also becoming increasingly popular in Mediterranean countries, such as Italy and Greece, where droughts are occurring more and more frequently.
Fisia Italimpianti’s extensive experience
Design capabilities, references from completed and fully operational plants, and financial viability: these are the critical factors for success in a developing market such as desalination. As it is part of the Webuild Group and has nearly 100 years of experience in the water industry, Fisia has cemented its position as one of the world’s leading players in the sector: it has constructed facilities and continues to operate in countries such as Saudi Arabia, Dubai, Abu Dhabi, Kuwait and Qatar.
For almost a century, the company’s guiding values have been those that inspired the people who founded the companies that have been merged into Fisia as it exists today. First and foremost, the desire to build projects around the world that meet the highest quality standards in order to fully satisfy the client, with a particular focus on safety and environmental aspects. And it is no small source of pride to know that its products are capable of delivering water to places where there was none, helping to achieve the UN’s goals of ensuring that millions of people have access to safe, clean water.
Conclusions
The world and the companies operating within it are having to deal with an exponential boom in the global population - with the resulting demands on the water supply - as well as increasingly extreme climate change and the development of technologies that consume ever-greater quantities of water. Desalination should be thought of as just one part of an integrated water management system which - with the combined contributions of desalination, water treatment and efficient reuse - will allow sustainable access to this increasingly precious commodity for every last person. As such, technology must evolve in a direction that leads us to develop systems with effective, low-investment technical solutions, as well as design solutions capable of reducing the consumption, and therefore the costs, of the water we produce. Lowering the production cost of water allows for the process to be used on a larger scale, facilitating widespread social and economic development.
