Is desalination the answer to global water shortage?

As population grows, water becomes more scarce

And as the global population burgeons and is expected to reach 9.7 billion by 2050, there has been an urgent need to embrace water technologies to address the worrying pressure this will place on resources. 

Among the innovations being touted is water desalination (desal for short), which has received a warm welcome from both government and industry players. The process of removing salt, impurities and other minerals on a massive scale so that the water can quench the thirst of millions and be used in other activities, like farming, largely involves two techniques.  The less technical one is the heating of sea or salty water to draw pure vapour, which is then cooled into liquid that is safe for drinking; the more complicated process, dubbed reverse osmosis, uses membranes that push water through filters at a high pressure in order to remove salt and other impurities. 

The over 20,000 desalination plants available globally embrace these processes, producing approximately 25 billion gallons of desalinated water every day. 

Up to 4 percent of the global water desalination initiatives are happening in the Middle East and North Africa, with the global market set to reach $32.1 billion by 2027.

“While desalination on its own cannot solve the global water crisis, it is proving to be one of the most effective ways of taming water loss and boosting supplies with the evolution of technologies involved in water recycling reaching millions who would otherwise struggle with access to clean and affordable water,” explained Matthew Wasike, a water engineer at the University of Nairobi. “This comes at a time when water has become a political and global issue of momentous proportions.” 

Governmental and private sector interventions

Aware of the threat that water scarcity poses to nations and their citizens, governments have spent millions of dollars on desalination initiatives. 

The protracted water wars pitting Egypt against Ethiopia over the Grand Renaissance Dam has expedited Egypt’s investment in desal efforts. The North African country has been keen to create new sustainable cities away from the Nile valley as it seeks to get more water to boost wheat production and farming.  The country’s sovereign wealth fund has been working on a $2.5 billion package in partnership with financiers to build and operate 17 solar-enabled desalination plants by 2025. This comes at a time when the government mulls public-private partnerships to construct 47 seawater desal plants to the tune of $8.5 billion by 2050. 

Earlier this year, Morocco switched on a desalination plant in Agadir - the largest in the country, estimated to have cost $470 million - in an effort to assist the water-stressed zones and farms in the area. It has a daily capacity of 400,000 cubic metres of desalinated water and will be used to irrigate close to 15,000 hectares that previously relied on scarce groundwater resources. 

Nations have also collaborated to share water resources while boosting desalination initiatives. In 2021, the Israeli government entered into a deal with water-stressed Jordan, in which Jordan would export 600 megawatts of solar power to Israel and in return receive 200 million cubic metres of desalinated water.

Namibia, among the driest countries in Africa, despite having access to the sea, is working with neighbouring Botswana to develop the Walvis Bay desalination plant, whose recycled water would be shared among the two Southern African countries. 

The Israel case study

Israel remains the model country in wastewater recycling and desalination. 

The water revolution that saw the Middle Eastern country turn a water-scarcity catastrophe into a model story was inspired by a heightened governmental campaign on water conservation, as well as investment in modern desalination plants to recycle water. Israel has the world’s largest seawater desalination plant, which has allowed the country to comfortably quench the thirst of its population and invest heavily in irrigated farming. As the country recycles almost 90 percent of its waste water  via sewage treatment plants, up to 80 percent of its drinking water comes from desalination. Israel intends to produce 1.1 billion cubic metres of desalinated water annually by 2025.

“The benefits of desalination go beyond the single-use value of the water produced. If coupled with water reuse for irrigation, desalination reduces groundwater abstraction and augments the water cycle,” noted a European Commission-backed study. “As such, it may support both adaptation to, and mitigation of climate change impacts by deploying plentiful water for human use, with all the benefits that entails, while helping preserve and restore ecosystems.” 

Beyond governments, private players have supported desalination efforts through investments of mega-projects and small-scale interventions. 

ACWA Power, a Saudi developer and operator of power generation and water desalination plants, has delivered desalinated water to 24 million people globally and has 16 water desalination plants in its fold. Earlier this year, it won a bid to develop the largest independent water desalination plant in Saudi Arabia that would produce 600,000 cubic metres of water daily. 

Berlin-based start-up Boreal Light has been working with millions of undersupplied people through an innovative model dubbed WaterKiosk. Last year, it supplied 23 Kenyan hospitals with solar-powered desalination systems which would provide more than 1 million litres of safe drinking water per day. It has expanded its services to other countries, including Somalia, Tanzania and Madagascar. 

But as desalination gets touted as a sustainable way of replenishing dwindling water supplies, there have been concerns about the exorbitant cost of energy involved in the process and its impact to the environment from carbon dioxide emissions, and the threat to marine biodiversity as a result of the dumping of salt and unwanted minerals into oceans. 

Enter green desalination

However, as technology advances, countries and organisations are tapping into modern innovations, like using renewable energy to enhance clean desalination. 

ACWA Power, while partnering with research and development company Water Global Access announced the integration of green water desalination technology in seawater desalination which would reduce energy consumption while ensuring that the byproducts released after desalination were completely green. 

“At a time when Africa is grappling with a high cost of energy and over 600 million of its population not connected to the national grid, energy conservation is key. And as the continent faces unprecedented water shortages, it has to accommodate modern and sustainable ways of recycling waste water management,” said Michelle Karimi a Water, Sanitation and Hygiene (WASH) specialist. “By being well endowed with renewable energy, the continent is at a pole position to embrace these clean energy sources in finding lasting solutions to water shortages. Desalination provides a plausible option.”

Image by Peter Campbell