The second annual Solar Challenge has begun in Chile's Atacama desert, where 15 solar-powered cars rolled out of an old salt mine.

The solar-powered prototypes will travel more than 1300km through the world's driest desert in the four-day, multinational race.

There are two categories: cars powered only by solar energy, and three-wheeled models that get a little help from pedals pushed by the drivers themselves.

The cars had to be built for less than US$7000 (NZ$8400), forcing their makers to be creative more than wealthy. Most of the teams represent university engineering departments.

The big finish comes Monday, and the winners get prizes of US$30,000 (NZ$36,000) in the solar category and US$9000 (NZ$10,800) in the hybrid category.

- AP