STUDENTS celebrated a college technology day by making solar stills to show how to produce clean drinking water for developing countries.

The stills, which are powered by the sun, turn polluted water or seawater into clean drinking water for emergency use.

About 300 students at Northallerton College, working in teams of 12, spent the day not only designing, making and testing the stills but also devising a marketing strategy to sell them as flat packs across the world.

Head of design and technology Steve Marshall, who led the team organising the project, said: "We wanted to challenge the students with a real and relevant problem."

The technology day was part of an eight-week programme designed to welcome 300 students who moved to the college from its partner school, the Allertonshire, two months early.