An Indian Institute of TechnoN Delhi, researcher has devised a, to produce potable water fi impure water using solar ent efficiently. The device, a solar a produces 20 per cent more w than other stills and gives 3 1 litres of clean water per sq metre day, reports Science For Villagesi 189/190, April, 1995. The pro@ involves the simple procedun condensation from a plastic ve by making use of san's rays.