New Chinese technology turns seawater into fresh water without electricity, costs less than bottled water

Scientists in China have developed a new solar-powered desalination technology that can turn seawater into fresh water without electricity. Desalination has always been an energy-hungry process that turns salt water into fresh water, making it largely the preserve of rich nations with abundant fossil fuel reserves.

Desalination usually requires a huge amount of energy and is often expensive. However, researchers have created a new material that uses sunlight more efficiently, making the process much cheaper. The researchers have designed a specialised method to weave nanoparticles into a three-dimensional photothermal evaporation material that absorbs solar energy to drive desalination.

Small trial site

The tests showed that the material achieved a solar absorption rate of up to 90.2 per cent, while cutting the energy required to evaporate the same volume of seawater by 45.7 per cent. The system successfully converted seawater into fresh water using only natural sunlight, without depending on any external power sources. The process was conducted at a small trial site, in which the fresh water produced was enough to irrigate 5 square metres (nearly 54 square feet) of farmland for a full growth cycle.

After two years, the team believe that using this technology, the cost of producing water would reduce below that of bottled water, offering a low-cost and sustainable solution to water shortages, especially in regions with limited access to electricity.