Renewables open up a sea of possibilities for sustainable desalination

The growing water crisis is forcing humanity to look to the sea to solve the problem. Desalination has emerged as a viable solution, but it needs clean energy to render it sustainable.

For many years now, when the water problem is discussed, our gaze has turned toward the sea. This horizon is where much of humanity’s hopes lie for drinking water, irrigation needs and to keep the economy working.

But seawater desalination has its own challenges. It’s an intensive process in terms of the consumption of electricity, often supplied by burning fossil fuels.

Fortunately, the winds of change are blowing in the right direction. Wind and sun rays, to be more exact. Solar and wind energy are now starting to power desalination plants, making the desal process more economic and sustainable.

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Desalination is redefining water’s future

On a planet where water seems to be everywhere, water shortages are, ironically, becoming an urgent issue. Consider the fact we probably all know by now: 71% of the planet might be covered by water, but 97% of it is seawater which cannot be drunk directly or put to everyday use.

Climate change, with its unpredictable weather patterns and rising temperatures, is aggravating an already challenging situation. By 2030, water consumption is forecast to grow by 50%. Yet two-thirds of the global population currently experience water shortages during at least one month every year, according to the UN.

Drought is hitting especially hard in Mediterranean countries, for example, as well as regions on the African continent, stressing the fragile balance between our water resources and the increasing demand for water for human consumption and agricultural and industrial uses.

“Two-thirds of the global population currently experience water shortages during at least one month every year”

In such context, seawater desalination is an increasingly viable solution to mitigate the effects of shortages. There are currently some 21,100 desal plants worldwide, operating to satisfy the daily water needs of over 300 million people. Arabian Gulf nations are the world’s largest producers of desalinated water, representing around 40% of global supply. Countries like Israel and Saudi Arabia have been committed to the technology for years in order to supply their populations’ needs.

In fact, today, the Saudis lead desalinated water production worldwide with a daily capacity that will have reached 13.32 million m³ by the end of 2024. The country has 43 desal facilities along its coast, distributed between the Red Sea and east coast. Among them, the biggest floating desal plant in the world with a daily production capacity of 25,000 m³.

Challenges facing desalination (and renewables as the solution)

The process of obtaining drinking water from the sea, however, is not exempt from challenges. The plants require costly infrastructure and a stable electricity supply, which normally depend on fossil fuels. It also needs careful management of the resulting salt concentration.

Reverse osmosis, one of the most used methods, requires around 3 kWh of energy for every m³of desalinated water (1,000 liters of water) produced. This is already a considerable advance if one takes into account that, a decade ago, it needed 20 kWh/m³, the Spanish newspaper El País reports.

Although there’s still a long way to go, the panorama is changing favorably with respect to the use of renewable energies for desalination processes. Wind and solar photovoltaic energies are driving a revolution in the sector.

A study by the Institute of Water and Environmental Engineering (IIAMA) at Valencia Polytechnical University highlights the enormous transformative potential of these renewable sources and augurs a more sustainable future for water production. Their research shows that integrating solar power in desal plants can reduce the cost of desalinating water by up to 24%, converting what was previously an expensive process into a more accessible and sustainable alternative. If, on top of that, they are combined with storage systems, the stability of the electricity supply is improved and ensures correct operation at all times.

“Integrating solar power in desal plants can reduce the cost of desalinating water by up to 24%”

A ray of hope – solar desalination in Saudi Arabia

The industrial city of Jubail, on the Arabian Gulf Coast, about 100 km from Dammam in eastern Saudi Arabia, is the location of one of the world’s most advanced desal plants, Jubail 3B. This project, led by ACCIONA in collaboration with SEPCOIII, has a capacity of 570,000 m³/day, enough to supply water to 2 million people in the cities of Riyadh and Qassim. But the most amazing thing about the J3B desal facility is it is connected to a solar plant, thanks to which it has achieved a reduction of electricity consumption from the grid of 20% per year.

Elsewhere, another country, Morocco, is not only mitigating the environmental impact of the desalination process by powering it with solar energy, it is also assuring a constant and sustainable supply of water for its population. This approach is crucial in a country where water shortages are a constant concern.

The challenge now is to extend these solutions to other regions of the world, especially those with productive agriculture that could benefit enormously from more affordable freshwater access. The combination of avant-garde technology and renewable energies promises to transform desalination into a key tool in tackling water stress and guaranteeing a more sustainable future for generations to come.

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