New solar still could bring clean water to world's poor

An affordable solar still that utilises the sun's power to provide clean water to many parts of the developing world has been shown off in prototype form by freelance industrial designer Gabriele Diamanti.

A traditional solar still works by suspending a plastic sheet above a hole that has a container for collection. The sheet is angled downwards, culminating at a point in the centre. As the sun heats the interior air (and any water-holding material within the still), water condenses on the sheet and runs down to the middle, dripping into the receptacle.

Diamanti's new 'Eliodomestico' works in a similar fashion - but purports to use the sun's energy to sterilise the water by "boiling".

It's this part of the design that is giving commentators such as Wired pause for thought: how is the energy of the sun supposed to boil the water, whether it's contained within a black 'boiler' or not?

Users pour dirty water into the top of the terracotta design, which then collects in the metal 'boiler'. According to Diamanti, the heat of the sun then "boils" the water - though he may simply be getting the word mixed up with 'evaporates' - and steam travels up and condenses on the sides of a pipe and is filtered down to a secondary collection dish. Coming back at the end of the day, you should find your water cleaned and ready for drinking.

The use of simple materials like this should allow for easy integration in places where clean water is hard to come by - if, of course, the design works as intended.