Solar-Powered 'Water Bank' Revolutionizes Irrigation for Urban Farms
Developed by Professor Li Jun and Dr. Zhu Jingling’s team at the NUS Environmental Research Institute (NERI), this solar-driven hydrogel irrigation device aims to enhance water efficiency in urban farming by capturing and reusing moisture. Their innovative research, recently published in Nature Water, addresses the pressing issue of water scarcity in places like Singapore.
Trying to grow plants in a small urban garden is akin to pouring water into a leaky bucket; much of it disappears before reaching the plants due to evaporation and plant transpiration. Prof Li’s team, in collaboration with Professors Wang Ruzhu and Huang Danfeng from Shanghai Jiao Tong University, has now devised a clever solution to trap water from the air, transforming it into a solar-powered "water bank." Instead of letting moisture slip away unused, the Transpiration and Evaporation Assisted Device (TEAD) "deposits" it into a storage system, collecting it at night when conditions are optimal. By day, the device "withdraws" the stored moisture, converting it back into liquid form for irrigation. Thus, every drop is accounted for, providing a reliable water source even in challenging climates.
At the core of this system is the TCP-Li gel, composed of various materials, including titanium nitride, which functions like a mini solar panel. This gel is responsible for absorbing sunlight and releasing the captured water. The TEAD device, roughly the size of a book, can be easily placed in any garden or greenhouse, quietly collecting water at night and releasing it during the day—no electricity or additional equipment needed.
This innovative approach can save up to 45% of the water typically lost, making it a game-changer for urban farms with limited space and resources. As cities such as Singapore face increasing water scarcity, this technology enables farmers to grow more food using less water, promoting sustainability and self-sufficiency.
“The research was driven by the urgent need to tackle global water shortages and improve agricultural efficiency, particularly in greenhouses,” explained Professor Li. “Traditional water extraction methods often involve complex systems and high energy consumption, which can be cost-prohibitive, especially for small to medium-sized operations. Our goal was to develop a practical and efficient solution for enhancing water recovery in greenhouses.”
Several unexpected findings emerged from the study, proving highly valuable. Prof Li was particularly pleased by the TEAD device’s performance in not only maintaining crop health under high temperatures but also adapting seamlessly to Singapore's variable weather without compromising efficiency. “It was an unexpected advantage,” said Prof Li. “The high water extraction rate also exceeded our expectations.”
Looking ahead, Professor Li outlined several future research directions, including optimizing the device's material composition, exploring system integration and automation, expanding its applications beyond greenhouses, and evaluating its long-term sustainability.
The future looks sunny for urban farms, as this "water bank" technology promises to store and recycle water more efficiently than ever. By continuing to refine the system, Professor Li and his team are ensuring that the "leaky bucket" of water wastage will soon be a thing of the past, helping farms thrive with every precious drop.
Please refer to the article published in Nature Water for more details:
“Solar-driven scalable hygroscopic gel for recycling water from passive plant transpiration and soil evaporation”
https://www.nature.com/articles/s44221-024-00265-y
For more details, please contact:
Professor Li Jun
E-mail: jun-li@nus.edu.sg