China's New Tech Turns Seawater Into Drinking Water, No Power Needed

Chinese scientists have developed a new solar-powered desalination technology that could make turning seawater into fresh water cheaper than buying bottled water, the South China Morning Post reported. Desalination has traditionally been an energy-intensive process, limiting its use mostly to wealthy nations with large fossil fuel reserves.

According to the South China Morning Post, researchers in China have built an outdoor prototype that ran for a full year with zero utility energy costs, powered entirely by sunlight.

The breakthrough lies in a newly designed photothermal material. Scientists wove nanoparticles into a three-dimensional structure that dramatically improves how efficiently sunlight is converted into heat to drive the evaporation process needed for desalination.

In tests, the material achieved a solar absorption rate of up to 90.2 per cent, while cutting the energy required to evaporate the same amount of seawater by 45.7 per cent compared with conventional methods.

At a small trial site, the system was used to desalinate seawater for irrigation, successfully watering around 5 square metres of farmland through an entire growing cycle. Remarkably, it needed no external power grid and relied solely on natural sunlight.

The research team estimates that, based on around two years of operation, the cost of producing water this way would drop below the price of bottled water, the South China Morning Post noted. They added that the savings would grow even further if the technology were scaled up or used over a longer period.

The innovation could offer a low-cost, sustainable option for regions facing water shortages, particularly areas with strong sunlight but limited energy infrastructure, without depending on expensive power supplies or fossil fuels.