SAUDI ARABIA STEPS UP AMBITIONS TO DEVELOP CUTTING-EDGE DESALINATION TECHNOLOGY
▶ Turning seawater into potable water is no longer an expensive last resort,
Every year, Saudi Arabia’s farmers use 21 cubic kilometres of water, pumped to the surface from the country’s fossil aquifers, a non-renewable resource found deep underground.
The kingdom’s households use 3.5 cubic kilometres a year.
In Ethiopia, the reservoir at the Grand Ethiopian Renaissance Dam, currently under construction, will be able to hold 74 cubic kilometres of water, which will mainly be used for hydroelectric power generation.
So, just how much water does a growing arid nation need?
Under Saudi Arabia’s plans to diversify its economy, the country will need vast quantities: the Red Sea tourism project will need at least 50,000 cubic metres of water a day, according to estimates.
This is a critical challenge, so it is no surprise the government blazed a trail investing in new technology to desalinate seawater.
Saudi Arabia, the UAE and Israel now receive more than half their water through this technology and invest significant resources in trying to make it more efficient.
Prior to this, the situation for water-stressed countries looked bleak. But desalination offers a chance for more arid countries to address water shortages, at least partially, now that the cost of the technology is decreasing.
Seawater desalination was once too expensive to be viable – in the 1960s, it cost $10 for every cubic metre – but the cost is now as low as 50 cents per cubic metre, or even less. This means it is no longer the preserve of wealthy countries.
“Ten years ago, the view of desalination was that it was a rich Arab state solution,” says Nizar Kammourie, chief executive of Sawaco, one of the leading desalination companies in Saudi Arabia.
“But this exclusive club has grown and you now have Spain, Australia and many US states involved.
“But even the largest plant in the US, the Carlsbad desalination plant in San Diego, which produces about 220,000 cubic metres a day, qualifies as medium-size in the Gulf. Everyone thought it was unsustainable, but now, it is seen as the only viable solution.”
Saudi Arabia is now a global leader in this technology, which is good news for everyone, especially millions of people worldwide who live in dry, coastal areas.
As with most technology, more investment eventually leads to lower cost.
Saudi Arabia now has the largest plants anywhere in operation: Al Jubail plant produces 1.4 million cubic metres a day.
Advances in desalination mean that in arid coastal cities such as Basra, Iraq, seawater desalination is now within reach, although Hartha, a major project in the country, is behind schedule amid a series of corruption allegations.
Even as recently as 10 years ago, the idea of a desalination plant in Iraq was unthinkable because of the cost.
The technology also used to present an environmental challenge for oil-rich countries.
Previously, the most common method of desalinating water involved burning hundreds of thousands of barrels of oil a day in thermal power stations and using excess heat to separate fresh water from salty brine.
The other common method involves using membranes with microscopic holes to separate water from salt using reverse osmosis.
Both methods are costly, although membrane technology is advancing, with some companies planning to use advanced materials such as graphene. There is also an environmental cost involved in disposing of extremely saline brine, which can affect maritime life, as well as a large carbon footprint.
But innovations, such as using solar power and more efficient membranes, create less brine and use less energy.
“A lot of this came down to energy cost,” Mr Kammourie says. “It used to typically require 7 to 8 kilowatt-hours per cubic metre in thermal desalination.
“But now, that is 3kWh in megaplants or even 2.5kWh. If you couple this with solar, it’s a real sustainable solution.
“We’ve been doing desalination with renewable energy, partial solar solutions; real-life experiments using all reverse osmosis tech.
“The biggest advancements are with membranes that can deal with higher salinity. But so far, that’s been incremental progress, not disruption.”
In 2019, Solar Water chief executive David Reavley took no fewer than 18 flights to the Middle East, pursuing a project to install revolutionary new technology in a new city: Neom, Saudi Arabia’s vision for a futuristic desert metropolis.
His company’s solar dome uses concentrated solar power – technology that already exists – to evaporate seawater inside a giant dome, separating fresh, potable water from extremely saline brine.
“We’ve taken this concept to an industrial scale and will be able to produce millions of cubic metres per year,” he says.
“From concept, it took about two and a half years to develop into a situation where there was a sufficient volume of water that could be produced.”
Work to treat water on an industrial scale was undertaken with a team from the Cranfield University in the UK.
“And that water from the dome will be drinking-water quality, meeting WHO guidelines, although for domestic use it would be remineralised,” he says.
With any desalination process, minerals that naturally occur in fresh water have to be added later.
This is because desalinated water is slightly acidic and can accelerate corrosion without the addition of minerals such as calcium that wash into freshwater from rocks.
“It’s not giving off pollution, it’s aesthetically pleasing to look at, it’s not ruining the horizon like a massive conventional power plant,” he says.
Mr Reavley says the technology can be adapted to several settings, from providing water to a coastal hotel to water for heavy industry, such as a project they are looking at in Jordan for the country’s fertiliser industry.
Sustainability is a central theme of the Neom project.
“Work has started, a site has been designated and construction will be starting shortly,” Mr Reavley says.
But he says the pandemic may affect the timetable. “Components are being manufactured, the designs and blueprints are fully completed for the site.”
Perhaps the most striking thing about the project – if fully realised – is the apparent cost: only $0.34 for every cubic metre.
“We’re now getting inquiries from all over the world, most recently in California,” he says. “There’s no shortage of interest – it’s just a question of being able to get on a plane.
“Through 2020, we were able to negotiate contracts in Jordan for work at phosphate mine sites. And we are talking about projects in Egypt. It has been slower than we would have liked.”
Despite facing similar delays, Mr Kammourie of Sawaco is also optimistic about the future.
“We’re seeing huge investment,” he says.
He points to Sawaco’s partnership with Saudi Arabia’s water and energy company Acwa Power on the desalination plant Rabigh 3, expected to come online by the end of the year.
It also linked up with Gradient, a US company, in 2014 to work on new technology that puts less brine back into the sea, a challenge the company has been trying to tackle since 2008.
“You have to innovate,” Mr Kammourie says. “Costs and margins are falling, and that comes from innovation.”
It’s not giving off pollution, it’s aesthetically pleasing to look at, it’s not ruining the horizon like a massive conventional power plant
DAVID REAVLEY
Chief executive, Solar Water