Researchers at King Abdullah University of Science and Technology (KAUST) in Saudi Arabia have developed a cooling system that operates without electricity, using salt and solar energy. The technology was detailed in a study published in the journal Energy & Environmental Science in 2025.
The system uses a salt solution that absorbs moisture from the air at night, then releases it during the day when heated by the sun, creating a cooling effect. This process, known as sorption-based cooling, can reduce ambient temperatures by up to 10°C (18°F) in dry climates, according to the research team.
Lead researcher Dr. Peng Wang stated that the system is designed for off-grid applications, particularly in arid regions where electricity is scarce. The prototype uses a salt called calcium chloride, which is inexpensive and widely available.
The technology is still in the prototype stage, with no commercial release date announced. The researchers are working to scale up the system for potential use in food preservation and building cooling in remote areas.
