Desalination: Demand Grows for Water Technology Amid Climate Change

Demand for desalination plants is growing as climate change makes fresh water scarcer

As one of the driest places on the planet, Saudi Arabia has excelled in extracting water from the sea to quench its people’s thirst.

And its use of the latest in technology on a grand scale saw it recently enter the Guiness World Records with Rabigh IWP, the largest facility in the world to use reverse osmosis to desalinate water.

Run by the utility ACWA Power, it produces 600,000 cubic metres of potable water every day for more than one million households in Makkah Al Mukarramah and Jeddah. “This will ensure the water security of many residents, along with pilgrims that this region welcomes during the holy month of Ramadan and the Hajj season,” read a statement by Abdulrahman Abdulmohsen AlFadley, Saudi Arabia’s Minister of Environment, Water and Agriculture, following news of the facility setting the record in March.

Saudi Arabia is already the biggest producer of desalinated water in the world at 22.9 million cubic metres a day. It puts the United States at a far second at 15.5 million, and China a distant third at 12.2 million, according to Global Water Intelligence, an industry publisher. The comparison is significant given how the kingdom has a much smaller population than the two giants: 36 million against 334 million and 1.45 billion, respectively.

Inflection point

But demand for the technology to convert sea water into potable water is growing as climate change brings drought to more countries like Italy, home to Fisia Italimpianti, one of the leading builders of plants that apply reverse osmosis, the most commonly used technology.

Data published in October by GWI DesalData, the research arm of Global Water Intelligence, show demand for the technology rising at an accelerated rate. Orders for plants to treat sea and brackish water were seen reaching 5.1 million cubic metres per day in 2021, up 8 percent from the previous year. “Although slow to arrive, we are clearly at the inflection point to ramp up this unique way to generate new water resources as a critical pillar to fight against climate change,” Carlos Cosin, president of the International Desalination Association, said of the data when they were presented at a conference that month. “Population growth, climate change, and resource scarcity make water reuse an increasingly in-demand technology.”

Desalination process: Efficient technology

Reverse osmosis has various stages. There is the pre-treatment of the water drawn out of the sea to the plant, which comprises filtration and the addition of chemicals to prevent the growth of micro-organisms. Then there is a high-pressure pump to remove the salts from the water by forcing it through a membrane. The pressure can be as high as 80 bar, or 1,180 psi (pound per square inch). A pressure vessel sends the water again through a membrane before a post-treatment process ensures certain minerals are returned to the water.

Among the major projects to apply this technology are Salalah in Oman and Shuaibah 3 in Saudi Arabia, which produces 250,000 cubic metres a day for more than one million residents in Makkah, Jeddah and Taif. Both were developed by Fisia Italimpianti of the Webuild Group, which has come to supply four million cubi metres a day of treated water for more than 20 million people.

Italy in crisis

In Italy, its home country, the hot, dry months have led to a water crisis, with major rivers like the Po running virtually dry. Although 32 percent of the population has limited access to potable water – especially in southern regions like Calabria and Sicily – the country uses desalination plants to meet a mere 4 percent of its water needs. “We need an immediate and structured plan to resolve once and for all the country’s deep water crisis, taking advantage of the positive momentum behind the development of infrastructure and the experience of institutions and entrepreneurs who together can provide solutions to the problem for the country and Italians,” said Pietro Salini, Chief Executive of Webuild.