ADVANCING SUSTAINABLE WATER DESALINATION

ACWA Power, which oversees the desalination of 6.8 million cubic meters per day. The two parties have been collaborating since 2019 to reduce the costs and carbon footprint of the desalination process in support of the Kingdom’s national energy and environmental goals.

Thomas Altmann, Executive Vice President of Innovation and New Technology, ACWA Power

development has led to improvements in the technology. KAUST aims to be at the forefront of innovation in this industry by developing effective ways to deploy new technologies at scale, ensuring the Kingdom’s water security.

Most new desalination plants utilize reverse osmosis, a membrane-based method that filters seawater by pushing it through a semipermeable membrane, allowing only fresh water to pass through. However, a significant challenge with reverse osmosis is biofouling, which occurs when microorganisms grow and multiply in the feed water, which in turn affects the quality and yield of the water produced.

JOHANNES

Director, Water Desalination and Reuse Center

Recent research conducted at KAUST is helping eliminate impurities in desalinated water, resulting in reduced energy consumption, lower maintenance costs and an increase in the process’ overall efficiency.

KAUST has a series of strategic partnership agreements with Saudi power company

Saudi Arabia’s water-scarce climate makes desalination essential for obtaining enough clean water to meet the needs of the growing population and economy. As of September 2022, the Kingdom relied on desalination for more than 60% of its water supply, producing around 20% of the world’s desalinized water, or approximately 9 million cubic meters per day. In 2023, Saudi Arabia’s desalination capacity reached 13.2 million cubic meters per day, most of which is produced by large-scale plants.

The process of desalinating water used to be seen as a costly, inefficient undertaking. However, investment in research and fundamental challenges the technology faces, such as how to uniformly cover a micrometer-sized pyramidal surface with perovskite. This has resulted in a tandem solar cell that combines perovskite top cells with industrially compatible, two-sided, textured silicon bottom cells. The perovskite top layer absorbs blue light best, while the silicon foundation absorbs red light, helping overcome the single-junction efficiency limit of silicon solar cells. This allows PVs to capture sunlight more effectively than traditional materials and convert it into electricity more efficiently.

KAUST’s recent research has found that specific antiscalants present in membrane filtration may contain biodegradable nutrients that result in biofouling. As a result, the university’s researchers have identified antiscalants that have a low risk of biofouling and have devised a sensitive testing approach that will support the development of a new generation of antiscalants, designed to mitigate potential risks.

KAUST’s findings are helping ACWA Power optimize production at its desalination plants. The Kingdom expects to benefit from such innovations as it looks to expand its current desalination infrastructure and boost production.

Tandem perovskite/silicon technologies are expected to comprise more than $10 billion of the global PV market by 2032, and the KSC expects to help drive this technological innovation. The KAUST team is exploring scalable methods to produce industrial-scale perovskite/silicon tandem cells with areas exceeding 240 square centimeters, as well as strategies to obtain highly stable tandem devices that meet critical industrial stability protocols.

To scale applications, the team must further develop its perovskite top-cell technology and test it in outdoor operating conditions. The research has shown great promise so far, and there is potential to significantly increase the efficiency of solar PVs and support Saudi Arabia’s goal of reaching net-zero carbon emissions by

“This new record is the highest power conversion efficiency of any twojunction solar cell under non-concentrated light, demonstrating the tremendous promise of perovskite/silicon tandems to deliver ultra-high performance photovoltaic modules.”