Saudi invention holds immense promise for a water-scarce world

‘Sun-rich’ countries such as Saudi Arabia and the UAE stand to reap the greatest benefits from the KAUST breakthrough in sustainable desalination technology. (Shutterstock)
Updated 24 July 2019

Saudi invention holds immense promise for a water-scarce world

  • Device built by KAUST researchers can turn seawater into potable water using solar power
  • Technology uses waste heat recovered from solar panels to power desalination process

DUBAI: The use of solar power to produce plentiful supplies of safe drinking water has long been seen as an answer to many of the Middle East’s pressing challenges relating to water and energy. Now a project at Saudi Arabia’s King Abdullah University of Science and Technology (KAUST) has raised hopes of just such a solution.

Researchers at the university’s Water Desalination and Reuse Center in Jeddah say they have developed a technology that uses waste heat recovered from solar panels to power a desalination process that produces clean water from seawater.

“The global solar panel installed capacity is huge, so the quantity of waste heat produced is enormous,” said Dr. Peng Wang, a professor at the center.

“We can use this to give us fresh water and also show us a very attractive future.”

Few regions in the world stand to benefit from such an invention as much as the Arabian Gulf. Saudi Arabia, for example, is one of the poorest countries in the world in terms of water resources per inhabitant, according to UN data. 


IN NUMBERS

 9% - Saudi Arabia’s electricity used for desalination of seawater

 38% - Middle East and North Africa’s share of global water-desalination capacity

40% - Saudi Arabia’s electricity from burning oil (2016)

40% - Saudi electricity demand rise expected over 2019-2030

40 gigawatts - Saudi solar PV energy capacity target for 2030

$100 billion - Investments needed globally by 2030 for solar applications


“Saudi Arabia produced close to 2 billion cubic meters of desalinated water in 2018, and it is estimated that by 2030, 50 percent of Saudi Arabia’s local oil and gas will solely be used to meet the domestic demand for fresh water," Peng said.

“The production of drinking water in Saudi Arabia consumes a lot of fossil fuels, which is not sustainable. The solar potential that the Kingdom has is massive. We say it has the best solar energy in the world, but we are not using it. We have the energy, but on the other hand we don’t have fresh water. So if you can use this energy to give you fresh water, it’s the best solution,” he said.

For two years, Peng has been working on developing a new, more sustainable desalination system. “We know that solar panels have a big problem of wasted heat,” he said, referring to photovoltaic (PV) modules that convert sunlight directly into electricity. “We decided to combine these two together — the heat coming from the solar panel and our desalination process.”

Thanks to advancements in technology, modern solar panels are increasingly effective in harvesting solar energy. According to Peng, solar panels can absorb more than 90 percent of incoming solar radiation. However, only 10 to 20 percent of this energy can be converted by most commercial solar panels into electricity.

“This means that about 80 to 90 percent of the harvested solar energy is actually converted to heat,” he said. “It is also the reason commercial solar panels get very hot in the daytime.”

In fact, solar panels across the Kingdom are known to record levels of up to 40C above the ambient air temperature during summer months. “If it’s 30C (ambient temperature), the panel can be as hot as 80C,” Peng said. “This means the solar panel suffers from some kind of drawback.”

Put another way, there are limits to the amount of sun’s heat that can be converted by a solar panel into electricity. “People have been working on various ways of cooling down solar panels, but so far it hasn’t been very successful,” he said. “At this stage, our device utilizes the waste heat (from solar panels) to give us something useful, which is drinking water.”

The device built by the research team can make both seawater and contaminated groundwater into drinking water. As of now, it can produce almost four liters of drinking water per hour using the heat from solar panels. “We believe this is a significant number, especially when you think of all the solar panels you have installed in the entire world,” he said.




‘Sun-rich’ countries such as Saudi Arabia and the UAE stand to reap the greatest benefits from the KAUST breakthrough in sustainable desalination technology. (Shutterstock)

“The calculation we have is also very attractive. It tells us that if every solar panel uses our device, we can have at least 10 percent of the world’s drinking water in about six years’ time — and this is a conservative estimate.”

Saudi Arabia, the UAE and the wider Gulf region are among the 122 “sun-rich” countries that lie either completely or partly between the Tropic of Cancer and the Tropic of Capricorn. In theory, at least, the amount of potable water production available to these countries could be doubled if sufficient numbers of solar installations were set up.

“You should expect drinking water coming out of these devices for the entire country,” Peng said, referring to Saudi Arabia, which has set ambitious renewable energy production goals for itself. According to the National Renewable Energy Program’s website, the target for energy from solar photovoltaics alone is 40 GW in 2030. “If by that time every panel in the Kingdom (includes) our device, by our conservative calculation is that they will produce more than 50 percent of the drinking water for Saudi Arabia.”

The research center’s breakthrough looks even more promising if the technology is adopted on a large scale. To this end, the scientists behind the device will have to carry out more work to enhance the system’s scalability and stability.

A scientific paper published on July 10 said the largest device the team was able to build so far measured 10 sq. cm. “At this point, we can double that size, but our target is to make it one square meter within the next 12 months,” Peng said. “This is the next step in our project.”

Stability is of equal importance since desalinating seawater is no easy matter given the harmful impact of high salt concentrations on the device. Scale formation due to salt precipitation inside the device is a problem that scientists are currently trying to solve, with answers including a system that can operate for long periods without major maintenance.




Prof. Peng Wang

“It’s a very attractive drinking-water production system, especially in decentralized facilities,” Peng said. “By decentralization, we mean producing drinking water in places where you have low-to-medium population density, such as off-grid small villages, small tribes, islands, all kinds of maritime activity and small towns with populations of about 10,000. Our technology is attractive to places in need of niche applications.”

Once the device is able to produce fresh water on such a scale, the next step could include dryland agriculture to grow plants or grass for sheep. “Farmers see an opportunity there,” he told Arab News. “With our device, you can have significantly more water. When you have water in a dry place and in arid to semi-arid regions, you can do many things that were once challenging.”

However, keeping the device’s manufacturing cost as low as possible will be critical if it to be affordable for impoverished areas. Although research is still in its early stages, the research scientists will have a clearer idea of the costs when they are able to build large-scale devices.

“Hopefully by next year, we will have a pilot-scale demonstration to show the world,” Peng said. “One branch under Saudi Arabia’s Ministry of Energy has already contacted us to express interest and they are talking about the possibility of granting us funds to help speed up the process. We are in negotiations with the government and other companies that are also interested in helping us.”

Looking to the future, Peng sees vast scope for the device, which has drawn attention to KAUST’s research expertise in water desalination and reuse.

“We will all run out of oil reserves at some point and solar is easily the most renewable energy known to us,” he said. “There are more than 800 million people in the world who have no access to clean water. Living in rural areas in underdeveloped countries, where the best infrastructure isn’t available, they look for decentralized drinking water solutions. Our technology should match this need very nicely.”

 


Saudi pursuit of ‘green Kingdom’ goal gets a boost

Updated 18 November 2019

Saudi pursuit of ‘green Kingdom’ goal gets a boost

  • Agreement between agriculture ministry and Dubai's ICBA aimed at conserving natural resources
  • Kingdom's biosaline agriculture research and systems stands to benefit from ICBA's expertise

DUBAI: Agricultural development and environmental sustainability in Saudi Arabia will receive a boost in the coming years, thanks to a new agreement between the International Center for Biosaline Agriculture (ICBA) in Dubai and the Saudi Ministry of Environment, Water and Agriculture.

The agreement aims to enable Saudi Arabia to achieve its goal of preservation and sustainable management of its natural resources by raising the quality of biosaline agriculture research and systems.

The ministry says that the agreement will make use of the ICBA’s expertise in capacity development besides agricultural and environmental research, especially in the fields of vegetation development, combating desertification and climate change adaptation.

“It also includes training programs for Saudi technicians and farmers,” the ministry said. “In addition, it will localize, implement and develop biosaline agriculture research and production systems for both crops and forestation, which contributes to environmental and agricultural integration.”

Dr. Ismahane Elouafi, the ICBA’s director general, told Arab News: “The agreement had been in the making for about two years. That was when we were approached by the Saudi government.”

Dr. Ismahane Elouafi, ICBA Director General, at the center's Quinoa fields in Dubai. (Supplied photo)

She said: “We put forward a proposal to demonstrate how the ICBA can help the Saudi government to implement its Green Kingdom Initiative, through which the ministry is trying to restore green coverage in the country and revive old conservation practices.”

Geographical features and climatic conditions very greatly from one part of the country to the other.

In the past, experimentation with such crops as potatoes, wheat and alfalfa proved detrimental to the Kingdom’s environment and natural resources due to faster rates of groundwater withdrawal.

“The ministry wanted to put a halt to over-abstraction of water, so they went through different policies,” Elouafi said.

“They made sure, for example, that farmers stopped producing wheat because about 2,400 liters of water is consumed to produce 1 kg of wheat. It was a huge amount,” she added.

“The new strategy is to find more appropriate crops for the farming community, which is quite large in the Kingdom.”

Saudi Arabia has been trying to grow its own food on a large scale since the 1980s. 

The objective of the Green Kingdom Initiative is to reduce the agricultural sector’s water demand by finding alternatives to thirsty crops.

The agreement will require the ICBA, over the next five years, to build for Saudi Arabia a new biosaline agriculture sector. 

As part of this shift, cultivation of a number of crops, notably quinoa, pearl millet and sorghum, will be piloted in high-salinity regions and then scaled up.

“The crops did very well in the UAE,” Elouafi said. “We’re looking at Sabkha regions, which have very high salinity and wetlands, and are on the ministry’s environmental agenda.”

Another objective is “smart” agriculture, which will involve raising water productivity, controlling irrigation water consumption and changing farming behavior.

Elouafi said that getting farmers in the Kingdom to stop cultivating wheat took some time as they had become accustomed to heavy government subsidies. In 2015, wheat production was phased out, followed by potatoes a year later and then alfalfa. 

“Farmers were provided everything to the point where they got used to a very good income and a very easy system,” she said.

“Now farmers are being asked to start producing something else, but the income won’t be the same, so it’s very important at this stage that the ministry has a plan and it’s fully understood.”

The agreement envisages preparation of proposals for ministry projects that involve plant production, drought monitoring, development of promising local crop and forestation varieties, and conservation of plant genetic resources.

“We’re also discussing capacity building because the ministry is big and has many entities. Because Saudi Arabia is a large country and has the capacity to meet some of its food requirements internally, what’s required is a better understanding of the country’s natural capabilities in terms of production of the crops it needs, like certain cereals,” Elouafi said.

“The way the authorities are going about it right now is more organized and more holistic. They’re trying to plan it properly.”

Elouafi said that having a better understanding of Saudi Arabia’s water constraints and managing the precious resource is essential.

 

Although almost the entire country is arid, there is rainfall in the north and along the mountain range to the west, especially in the far southwest, which receives monsoon rains in summer.

 

Sporadic rain may also occur elsewhere. Sometimes it is very heavy, causing serious flooding, including in Riyadh.

“They (the government) are very interested in drought management systems. The Kingdom has a long history of agriculture,” Elouafi said.

“It has large quantities of water in terms of rainfall, and certain regions have mountainous conditions, which are conducive to agriculture.”

Clearly, preservation of water resources is a priority for the Saudi government. But no less urgent is the task of conversion of green waste to improve soil quality, increase soil productivity and water retention, and reduce demand for irrigation.

The Kingdom is one of at least three Gulf Cooperation Council countries that are taking steps to develop a regulatory framework for the recycling of waste into compost.

Saudi Arabia, the UAE and Oman are respectively aiming to recycle 85 percent, 75 percent and 60 percent of their municipal solid waste over the next decade, according to a report by the Economist Intelligence Unit (EIU) entitled “Global Food Trends to 2030.”

Saudi Arabia and the UAE rank in the bottom quartile of the 34 countries covered by the EIU’s Food Sustainability Index, with low scores for nutrition and food loss and waste. 

The answer, according to many farmers, policymakers and food-industry experts, is a shift toward more sustainable management of each country’s natural resources.