China has achieved a new breakthrough in solar energy, increasing the efficiency of water desalination using sunlight. This achievement could make producing drinking water from seawater cheaper than bottled water.
With global freshwater shortages, water purification and reuse have become critical, but the technologies behind them remain heavily reliant on fossil fuels, making them impractical for harsh regions.
Although solar thermal evaporation is a promising method for water treatment in such areas, its use is limited by inefficiencies and operational limitations.
Now, scientists from the Chinese Academy of Sciences have developed a new three-dimensional (3D) structure that significantly improves the efficiency of this technology for converting seawater into drinking water.
This structure contains tightly bound polymer chains with hollow shells, which provides a record-breaking evaporation rate, 8.5 times higher than previously recorded figures for this technology.
According to scientists, this unique structure maximizes sunlight absorption and reduces energy consumption for evaporation by almost 50 percent.
«"This structure exhibits 90.2 percent broadband absorption of solar radiation and reduces the energy consumption for evaporation by 45.7 percent," the scientists wrote in a study published in the journal Advanced Materials .
Tests also showed that the materials used have good strength and reliability during long-term use.
«"Excellent photothermal conversion and water transport capacity enable such outstanding evaporation performance," said Van Dan, one of the study's authors.
The researchers then used this material to create a real-world outdoor desalination device.
With natural sunlight, the system produced 20 liters (5.33 gallons) of fresh water per day, which met World Health Organization drinking water standards.
Scientists noted that this small installation, occupying only about 0.75 square meters, can produce enough water to meet the basic daily drinking needs of approximately 10 people.
The desalinated water produced by this device was also successfully used to irrigate a small field.
«"The resulting water successfully supported the full growth cycle of various crops in a five-square-meter demonstration plot at a lower cost," the scientists wrote.
The water produced by this system enabled the full growth cycle of spinach, corn and Chinese cabbage, indicating the potential for this technology to support agricultural irrigation in water-scarce regions.
Researchers estimate that after two years of operation, the cost of water produced using this technology will be lower than the cost of bottled water sold in stores.
They hope the new material could offer a practical solution for sustainable freshwater production in regions facing water shortages.