After an attack on tourists in the divided state of Jammu and Kashmir, the Indian government said it was suspending a water sharing treaty with Pakistan, bringing the two nuclear-armed powers to the brink of war. Mexico’s president, Claudia Sheinbaum, acceded to Trump Administration demands that her country deliver an enormous amount of water to Texas farmers, at the expense of Mexican farmers suffering from a long, severe drought. These global headlines underscore the increasing importance of desalination technologies in a warming world.
Since my December 2024 article, Flocean’s Deepwater Desalination Reforms A Vital But Costly Industry, I’ve done a good bit of research on desalination technology. My research convinced me that desalination will become increasingly vital the further we move into the post-Climate 21st century.
Here are the trends I see:
- Increasing demand: A combination of stresses from urbanization, greater industrial use (See my recent article about Nexalus to learn how water can be used to save water), and drier, hotter weather due to climate change is spurring demand.
- Decreasing supply: Overuse of slowly recharging natural aquifers and pollution of rivers and groundwater are making it harder to find freshwater, a challenge only marginally offset by improvements in water treatment and recycling.
- Increasing human stakes: The World Resource Institute estimates that 25% of the world’s population faces extremely high water stress, and a billion more will live in areas with extreme water stress by 2050. Worryingly, many facing the highest water stress live in quickly growing areas such as India and China.
According to a recent Bank of America analysis, the desalination market was worth $15.2 billion in 2022 and is projected to grow at an annual rate of 10.5%, reaching $33.4 billion by 2030.
Desalination Technologies: A Quick Overview
The Age of Exploration would not have been possible without desalination aboard ships transiting to the Americas and the Spice Islands. Onboard stills boiled saltwater and captured the fresh condensate.
After World War Two, Middle Eastern countries, flush with oil and the cash that came with it, built huge, oil-burning desalination plants based on the same principles as the shipborne stills. This technological pathway, called thermal desalination, was dominant until around 2000 and comes in two flavors: Multi-Stage Flash and Multi-Effect Distillation. MSF is the easiest to scale and was thus the dominant technology in the Middle East for years. It is phenomenally energy-intensive but can be made less so if paired with electricity generation. MED is much more energy efficient but harder to scale, so these plants are usually used on remote islands with limited fuel resources.
Research into membrane-based desalination using reverse osmosis began in the U.S. in the 1950s in response to a local drought in California. Spain’s arid climate and lack of domestic fossil fuel resources focused national R&D programs on RO desalination. This technology uses powerful electric pumps to push seawater through special membranes that allow freshwater to pass through while blocking salt.
The price of desalinated water decreased about 45% between 2012 and 2022, according to a 2023 analysis by Utah Tech University professor Gale L. Pooley. Improvements to RO systems, especially modularization and energy recovery, were a big factor in this price reduction.
The Ecological Cost of Conventional Desalination
While climate change threatens the freshwater resources humans rely on, the carbon footprint and other ecological impacts of conventional desalination methods exacerbate climate change and ecosystem loss.
Energy consumption is the main driver behind desalination’s carbon footprint. Desalination, whether by burning fossil fuels to boil water or using electricity to force water through a membrane, requires a lot of energy.
CO₂ emissions from desalination facilities are substantial, estimated to be around 120 million tons annually. Extrapolating the growth of desalination services over the next several decades, the carbon footprint of providing freshwater globally could reach 218 million tons by 2040 and 400 million by 2050.
Seawater is typically drawn from the top 20 meters of the sea, which is teeming with biological activity. The first step in both thermal and RO desalination is to filter and chemically treat the seawater with biocides and coagulants to remove organics. After the desalination process is finished, highly concentrated brine and chemical waste is released into offshore tidewaters, wreaking havoc with sensitive coastal ecosystems.
Another ecological impact that cannot be overlooked is onshore land use. Desalination plants can take up a lot of real estate, crowding out other agricultural or other potential users.
The Competitive Environment for Desalination
There are some very large legacy players in the desalination business, including French Veolia Water Technologies (a subsidiary of Veolia Environment and acquirer of Suez), Korean firms Doosan Enerbility and GS Inima, Spanish firms Abengoa, Acciona Agua, and Aqualia, and Israeli firm IDE Technologies.
These companies have staked out geographical territories and technical competencies and are focused on designing, building, and sometimes operating the largest desalination plants on earth, some generating millions of cubic meters of freshwater per day.
I am more excited about smaller, modular competitors, especially because smaller companies are finding creative ways to reduce desalination’s ecological impact.
Barge-Based Desalination
Several years ago, Metito, a Middle Eastern company, outfitted barges with modular RO desalination equipment and supplied them to the Saudi Water Authority, the largest buyer of desalination services in the world. Since then, other floating desal projects have been discussed for regional water shortages in Spain and elsewhere. I spoke with the CEO of a Norwegian firm, EnviroNor, which repurposes decommissioned freighters with desalination equipment to service the needs of coastal communities. EnviroNor has teamed up with Japanese shipping and logistics giant Mitsui OSK Lines to commercialize this business, and the team is actively bidding projects.
Barge-based desalination solves land-use issues and expels waste in offshore waters that dilute it more readily, but most of the ecological issues associated with desalination are still evident, since shipborne desalination still requires the same amount of energy and chemicals to run as legacy systems.
Wave-Powered Desalination
The Canadian firm Oneka and the Norwegian firm Ocean Oasis are working on modular, floating desalination buoys that use wave power to provide low-carbon-footprint freshwater to coastal communities. In answer to written questions, Oneka’s CEO told me that the company started with smaller projects, oftentimes benefiting remote coastal communities, but intends to scale up to an output of up to 10,000 cubic meters per day by adding modular desalination units.
Clearly, this solution greatly reduces the carbon footprint of a desalination project, since desalination’s energy requirements are provided by renewable wave power. It also reduces pressure to use valuable land and expels brine and chemicals offshore, rather than in sensitive ecological tidewaters.
This approach’s biggest drawback in my mind is scalability, especially within the engineering difficulties associated with the rough offshore environment. The buoys are relatively small and light, so storms and high waves must play havoc with their anchoring and piping systems and the actual desalination equipment.
Subsea Desalination
Three firms are taking the lead in this field: Flocean and Waterise from Norway and OceanWell from the U.S. Of these, Flocean looks to be the most commercially and technically advanced, having already conducted a commercial pilot in the Red Sea and, according to CEO Alexander Fuselang, is closing in on further commercial announcements. Waterise has announced partnerships and memoranda of understanding, but seems to still be waiting for approval to start a commercial pilot. OceanWell is focused on the U.S. market and announced a pilot project off the coast of southern California, but is also awaiting permitting approval.
I like subsea desalination for its attenuation of ecological harm and its readiness to scale. Subsea RO desalination, performed at around 500 meters below the surface, uses the enormous weight of the water column to push saltwater through membranes, resulting in a 35%-50% reduction in desalinization’s energy requirements. This energy might be supplied by wave power or on-shore solar or wind, reducing the carbon footprint even further. Also, intake water is drawn from deeper than the level which sunlight can penetrate, so biological activity and organic matter is extremely low, requiring less harsh chemical pretreatments that wind up as toxic waste. The brine can be dispersed over the sea floor and diluted by currents.
The downside of subsea desalination is that servicing units is not as straightforward as sending someone aft with a wrench. That said, periodic servicing of Flocean’s desalination modules can be done using the same equipment and techniques as for subsea oil and gas equipment. The company also includes redundancies in its planned modular facilities. Each desalination operation will have eight modular units, one of which is “hot-swappable,” held in reserve in case another unit malfunctions or needs to be serviced.
Desalination Will Soon No Longer Be “Nice-to-Have”
Human habitation wouldn’t be possible in some parts of the world without desalination. As the climate heats up, soils dry up, more people move to coastal urban centers, and more water is used for industrial and agricultural purposes, desalination will only become more important. If you are interested in a more in-depth picture of the supply/demand dynamics of the desalination market and want to learn more about Flocean’s approach to desalination, please take a look at the detailed research report I just published.
I received a message from a contact in Spain who recounted her shock when her tap ran dry during the recent blackout. It does not require too great a leap in this post-Climate world to imagine a dry tap becoming a daily or weekly occurrence rather than a one-off, and that mental experiment piques my interest in desalination. Intelligent investors take note.