The solar-powered ‘tree’ that turns the sea into drinking water
- Material that generates heat from sunlight could provide self-maintaining water supply on remote islands
A Chinese-led international research team has created a “tree” that can generate clean drinking water.
Drawing its energy entirely from the sun just like a real tree, the “water tree” has a root made of cotton fabric that can absorb water from its surroundings, such as from sand on a beach.
After water moves up the stem, it is vaporised by “leaves” made of black-carbon paper cones that convert light energy to heat, reaching nearly 50 degrees Celsius (122 Fahrenheit). The tree sits in a glass chamber with a relatively cool surface that collects the vapour.
Using standard cotton fabric and a new nanomaterial that can be cheaply mass-produced from charcoal, a paper cone with a surface area as large as 1 square metre would cost only US$2, according to the researchers.
A cone that size can generate up to 3.4kg (7.5lbs) of condensed water per hour, faster than any other solar-powered desalination methods previously reported.
Even on a cloudy day, the total output in seven hours of sunlight can reach 5.4kg, or three times the amount the typical adult needs to stay hydrated.