The innovators: desalination unit brings clean water on wheels

Portable 'Desolenator' makes sea water and rain fit for human consumption

Travelling around Thailand in the 1990s, William Janssen was impressed with the basic rooftop solar heating systems that were on many homes, where energy from the sun was absorbed by a plate and then used to heat water for the home.

Two decades later and Janssen has developed that basic idea he saw in south-east Asia into a portable device that uses the power from the sun to purify water.